Urea production reporting

by aliazharch» Mon Apr 01, 2013 10:30 am

Dear Friends,

At our Urea plant, 3 different totalizers are available for urea production reporting i.e Ammonia totalizer, CO2 totalizer and Weigh scale totalizer. However, we use Ammonia totalizer to declare the production due to its consistency in accuracy.

Has anyone of you used Weigh scale totalizer for declaring Urea production?

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Re: Urea production reporting

by Basheer» Mon Apr 08, 2013 12:26 pm

to my knowledge, Ammonia mass flow meter is used to declare the production on daily basis. However, production test is carried out every 2 months by using the trucks weigh scale and hence coreect the ammonia to urea ratio.

regards

Basheer Ali Al-Awami
Saudi Arabia
T +966 (3) 340 6160
F +966 (3) 340 6217

Basheer

Posts: 3

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Title: Director - Technical Operation (Urea)

First name: Basheer

Last name: Al-Awami

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Company: Sabic

Country: Saudi Arabia

Urea Plant Technology: Stamicarbon and Snam

Final product: Granules

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Re: Urea production reporting

by norozi1972» Mon Apr 08, 2013 2:28 pm

Dear Freind
I think , final weigher that located on the belt before urea storage can be useful for declaring of production.
Ammonia and CO2 totalizer can help for accuracy.Test run should be done every one or two month by truck.Ammonia and CO2 totalizer is a compensative device with temprature and pressure that can be sometime wrong and have a flauctuation.
with best regard
khpc-iran
norozi

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Re: Urea production reporting

by m.farooq» Tue Apr 09, 2013 10:21 am

dear friends,

i do agree that at urea plant all of these totallizer are used to moniteer the urea production. rate. weighing scale at belt conveyer is among good option , but there are some associated problem due to dust at bottom of prilling tower and normaly one faces problem in accuracy in dusty conditions . production test of course is important is counter check . At our plant we have preferred ammonia base production and factor of production is calibrated after production test . additionally one can use molten urea line totallizer as well
regards.

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Calculation of Urea Production

by alokjaiswal» Mon Sep 02, 2013 6:35 am

Dear all,

I wish to know
1. How the Urea Production is calculated?
2. If it is calculated from Ammonia flow-meter, then how the accuracy of flow-meter is checked i.e. the physical Urea matching with calculated Urea.

Regards,

Alok

alokjaiswal

 

Posts: 2

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First name: Alok

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Country: India

Urea Plant Technology: Stamicarbon

Final product: Prills

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Re: Calculation of Urea Production

by GIRISH PRAKASH» Mon Sep 02, 2013 12:23 pm

Dear Alok,

It may not be accurate to calculate the Urea production from ammonia flowmeter rate.

Regards,
Girish

GIRISH PRAKASH

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Posts: 124

Joined: Fri Oct 23, 2009 4:40 am

First name: GIRISH

Last name: PRAKASH

Department: Manager - Urea

Company: Tata Chemicals Ltd., Babrala

Country: India

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Re: Calculation of Urea Production

by norozi1972» Mon Sep 02, 2013 3:16 pm

dear friend
there are many ways for calculation of urea production:
1-by ammonia consumption
2-by co2 consumption
3-by concentrated urea flow meter that installed before first urea evaporator or after final evaporators .
4-by weigher installed on the belt before going to product storage.
all mentioned ways can accurate with a direct or indirect test run minimum per month.
with best regard
norozi

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TRe: Calculation of Urea Production

by Reduxe» Tue Sep 03, 2013 12:24 am

Dear All
Urea Production is digitally calculated by a weight cell located in the final belt before the storage house. But there is some deviation between the actual production and the main plant load so we compare it by using the NH3 feed flow meter which gives us the main flow during the operation day ( 45 T/D )
45 * 24 = 1080 T of NH3 consumption
1080/0.566 = 1908 T of Urea produced ( every one ton of urea produce by reaction of 0.566
Ton of NH3 )
So the load of urea plant is
1908/17.5 = 109.03 %
So we compare the result with the actual production then we make a factor which controls that process ( you need to check that factor during operation )
All the above calculations can be made by using CO2 flow meter also ( every one tone of urea produced by react of 0.733 Ton of CO2 ) .
Thank you

 

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Final product: Granules

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Re: Calculation of Urea Production

by alokjaiswal» Thu Sep 05, 2013 10:58 am

Dear all,

As rightly mentioned, Urea production can be calculated by Ammonia from specific consumption of 0.566 MT/MT or by CO2 from specific consumption of 0.733. But again I have some doubts.
1. Will it not be accurate to take Ammonia or CO2 losses into account?
2. If any Industry is taking losses into account, then how much is being taken into account?
3. What about ammonia flow-meter reading? How much accurate is its reading owing to the fact that ammonia is highly volatile.

Request industry professionals to share their experience.

Regards,
Alok

alokjaiswal

 

Posts: 2

Joined: Sat May 12, 2012 4:46 am

Title: Mr

First name: Alok

Last name: Jaiswal

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Company: IFFCO

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Final product: Prills

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Re: Calculation of Urea Production

by GIRISH PRAKASH» Sat Sep 07, 2013 4:02 pm

Dear Alok,

If you do not take the losses into account, the declared production will be always inaccurate. It is very easy to account for the losses. As far as ammonia metering is concerned, the accuracy also depends on the type of flowmeter used for measuring the flow.

Regards,
Girish

GIRISH PRAKASH

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Posts: 124

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Department: Manager - Urea

Company: Tata Chemicals Ltd., Babrala

Country: India

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Re: Calculation of Urea Production

by KASHIF NASEEM» Sat Sep 14, 2013 8:03 pm

Carry out the actual load test and record the values of flow meters on monthly basis and find the optimum consumption ratios and then use these ratios to calculate the urea production.
Before load test calibrate the flow meters as per instrumental compensation factors.

MUHAMMAD KASHIF NASEEM
SR.PROCESS ENGINEER
SAUDI BASIC INDUSTRIAL CORPORATION (SABIC)
KINGDOM OF SAUDIARABIA
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+966596560770

Methods of Monitoring and Analysis

Guidance for assessment of representativeness and reliability of baseline environmental attributes

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Natural gas testing expertise.

SAFETY MOVEMENT HISTORY

Women and Hunger: 10 Facts

1. In developing countries, 79 % of economically active women spend their working hours producing food through agriculture. Women are 43% of the farming work force.
2. Yields for women farmers are 20-30 percent lower than for men. This is because women have less access to improved seeds, fertilizers and equipment.
3. Giving women farmers more resources could bring the number of hungry people in the world down by 100 - 150 million people.
4. Surveys in a wide range of countries have shown that 85 - 90 percent of the time spent on household food preparation is women’s time.
5. In some countries, tradition dictates that women eat last, after all the male members and children have been fed.
6. When a crisis hits, women are generally the first to sacrifice their food consumption, in order to protect the food consumption of their families.
7. Malnourished mothers are more likely to give birth to underweight babies. Underweight babies are 20 percent more likely to die before the age of five.
8. Around half of all pregnant women in developing countries are anaemic. This causes around 110,000 deaths during child birth each year.
9. Research confirms that, in the hands of women, an increase in family income improves children’s health and nutrition.
10. Education is key. One study showed that women's education contributed 43% of the reduction in child malnutrition over time, while food availability accounted for 26%.

Women in the developing world: facts and stats

Women and climate change

Women in Dola, Nepal, construct a pond to irrigate their vegetable gardens. With this pond and drought-resistant seeds, they now have a sustainable food supply.

Women make up 20 million of the 26 million people estimated to have been displaced by climate change.
Women are often hit much harder during disasters. In the Bangladesh cyclone of 1991, the number of women who died was five times greater than the number of men. They had not been taught how to swim and received no prior warning of the event. In the tsunami that hit Sri Lanka in December 2004, many more women perished than men because they did not know how to swim or climb trees.
In southwest Bangladesh, the salinisation of drinking water has meant that many women are forced to walk long distances – up to 10km every day – just to fetch water.
Droughts in the Philippines are making it increasingly difficult for women to search for food, fuel and water, all of which were previously accessible in towns. In rural areas, women and girls are being forced to walk for hours to fetch water. This makes them more prone to accidents and acts of violence.
After a food crisis, women and children often give up their meals for the men, increasing their susceptibility to malnutrition.
Increasingly unpredictable and extreme weather is affecting harvests and making it harder for the poorest people, especially women, to provide food for their families. In many developing countries, rural women produce up to 60% of household food, and are major producers of the world’s staple crops (such as rice, wheat, maize), which provide up to 90% of the rural poors' food intake.

• Read more on Oxfam's work on climate change

Women and food

Oxfam is helping communities establish vegetable gardens in the Highlands of Papua New Guinea.

Women produce the majority of the world’s food but do so under difficult conditions.
On Sub Saharan African farms, 75% of the workforce are women, they produce 80% of the household food but they only own 1% of the land and are rarely included in the decision making (either on agricultural production or at a household level).
Research has shown that farms run by educated women show increases in yields of up to 22%. Yet two-thirds of the children denied school are girls and 64% of the world’s illiterate adults are women.
Women worldwide rarely own land: in Sub-Saharan Africa women own 1% of the land, in Brazil they own 11% and in Peru 13%. Lack of land rights means women are frequently the ones left dispossessed and uncompensated. When women do own land, their holdings are smaller than their male counterparts – between 20% and 35% on average worldwide. Such land is often marginal and thus of low productivity.
Women face discrimination in terms of access to credit, tools, training and a variety of other agricultural services. Available figures show that only 5% of extension services have been addressed to rural women, while no more than 15% of the world's extension agents are women. In Africa women receive 7% of extension services and 10% of the credit to small-scale farmers. When women do obtain credit the average value is 42% of what is granted to male farmers, and often a much higher percentage of collateral is required (collateral that women rarely have, see earlier point).

• Read more on Oxfam's work on livelihoods

Women and increasing food prices

Women and children living in poverty will be hardest hit if global food prices continue to rise. In many countries it is women who are responsible for feeding their families and, when times are hard, it is women who go without to allow their husbands and children to eat.
Governments must act now and act together to help those already facing the crisis, to avert another global crisis and to help end hunger for the almost one billion people who go to bed hungry every day.

- See more at: http://www.oxfam.org.nz/what-we-do/issues/gender-equality/women-in-the-developing-world#sthash.FNHF12KV.dpuf

Women in the developing world: facts and stats

Women and climate change

Women in Dola, Nepal, construct a pond to irrigate their vegetable gardens. With this pond and drought-resistant seeds, they now have a sustainable food supply.

Women make up 20 million of the 26 million people estimated to have been displaced by climate change.
Women are often hit much harder during disasters. In the Bangladesh cyclone of 1991, the number of women who died was five times greater than the number of men. They had not been taught how to swim and received no prior warning of the event. In the tsunami that hit Sri Lanka in December 2004, many more women perished than men because they did not know how to swim or climb trees.
In southwest Bangladesh, the salinisation of drinking water has meant that many women are forced to walk long distances – up to 10km every day – just to fetch water.
Droughts in the Philippines are making it increasingly difficult for women to search for food, fuel and water, all of which were previously accessible in towns. In rural areas, women and girls are being forced to walk for hours to fetch water. This makes them more prone to accidents and acts of violence.
After a food crisis, women and children often give up their meals for the men, increasing their susceptibility to malnutrition.
Increasingly unpredictable and extreme weather is affecting harvests and making it harder for the poorest people, especially women, to provide food for their families. In many developing countries, rural women produce up to 60% of household food, and are major producers of the world’s staple crops (such as rice, wheat, maize), which provide up to 90% of the rural poors' food intake.

• Read more on Oxfam's work on climate change

Women and food

Oxfam is helping communities establish vegetable gardens in the Highlands of Papua New Guinea.

Women produce the majority of the world’s food but do so under difficult conditions.
On Sub Saharan African farms, 75% of the workforce are women, they produce 80% of the household food but they only own 1% of the land and are rarely included in the decision making (either on agricultural production or at a household level).
Research has shown that farms run by educated women show increases in yields of up to 22%. Yet two-thirds of the children denied school are girls and 64% of the world’s illiterate adults are women.
Women worldwide rarely own land: in Sub-Saharan Africa women own 1% of the land, in Brazil they own 11% and in Peru 13%. Lack of land rights means women are frequently the ones left dispossessed and uncompensated. When women do own land, their holdings are smaller than their male counterparts – between 20% and 35% on average worldwide. Such land is often marginal and thus of low productivity.
Women face discrimination in terms of access to credit, tools, training and a variety of other agricultural services. Available figures show that only 5% of extension services have been addressed to rural women, while no more than 15% of the world's extension agents are women. In Africa women receive 7% of extension services and 10% of the credit to small-scale farmers. When women do obtain credit the average value is 42% of what is granted to male farmers, and often a much higher percentage of collateral is required (collateral that women rarely have, see earlier point).

• Read more on Oxfam's work on livelihoods

Women and increasing food prices

Women and children living in poverty will be hardest hit if global food prices continue to rise. In many countries it is women who are responsible for feeding their families and, when times are hard, it is women who go without to allow their husbands and children to eat.
Governments must act now and act together to help those already facing the crisis, to avert another global crisis and to help end hunger for the almost one billion people who go to bed hungry every day.

- See more at: http://www.oxfam.org.nz/what-we-do/issues/gender-equality/women-in-the-developing-world#sthash.FNHF12KV.dpuf

Abnormal levels of Nitrogenous Compounds generally indicates pollution. Most of the nitrogen found in water originates from the decay from the remains of plants and animals. Ammonia Nitrogen is the most common form of nitrogen from an effluent involving the biological breakdown of animal waste products. Since it is readily oxidizes to either nitrite or nitrate under aerobic conditions, high amounts of this pollutant may indicate a fairly fresh or recent pollution event. Although to a lesser extent than nitrate-nitrogen, ammonia can be utilized by aquatic plants and algae to support their growth. Examples of sources of this type of nitrogen would be from wastewater treatment plants, failing septic tank systems, and runoff from livestock farms. When dissolved oxygen is readily available, bacteria quickly oxidize ammonia to nitrate through a process known as nitrification. Other types of bacteria produce ammonia as they decompose dead plant and animal matter. Depending on temperature and pH (a measurement of “acidity”), high levels of ammonia can be toxic to aquatic life. High pH and warmer temperatures increase the toxicity of a given ammonia concentration. High ammonia concentrations can stimulate excessive aquatic production and indicate pollution. Important sources of ammonia to lakes and streams can include: fertilizers, human and animal wastes, and by-products from industrial manufacturing processes. Techniques to prevent high ammonia concentrations involve filtration of runoff water especially from barnyards and other areas where animals may be kept in larger numbers, proper septic system maintenance, and not over-fertilizing yards or fields.
In order to understand and remove nitrogen when it threatens the stability of your water source, you must understand the different forms of nitrgen and some commonly referred to terms that you will be dealing with.    

• Total Nitrogen is the sum of all nitrogen forms (TKN + NO2 + NO3)
• Total Kjeldhal Nitrogen (TKN); this is the sum of NH3 + Organic Nitrogen
• Ammonia Nitrogen (NH3)
• Nitrite (NO2)
• Nitrate(NO3)
• Nitrogen Gas (N2)
• Refractory Nitrogen is the Nitrogen that is not biologically decomposable

Each of these nitrogen components play a role in the overall nitrogen manifestation in water quality. For example, for every 1 part ammonia(NH3) converted to nitrate (NO3) - 7.1 parts of alkalinity are depleted, and for every 1 part nitrate (NO3) removed - 3.6 parts alkalinity are recovered.  

Nitrogen-containing compounds act as nutrients in streams, rivers, and reservoirs. The major routes of entry of nitrogen into bodies of water are municipal and industrial wastewater, septic tanks, feed lot discharges, animal wastes (including birds and fish), runoff from fertilized agricultural field and lawns and discharges from car exhausts. Bacteria in water quickly convert nitrites [NO2-] to nitrates [NO 3 -] and this process uses up oxygen. Excessive concentrations of nitrites can produce a serious condition in fish called "brown blood disease." Nitrites also can react directly with hemoglobin in the blood of humans and other warm-blooded animals to produce methemoglobin. Methemoglobin destroys the ability of red blood cells to transport oxygen. This condition is especially serious in babies under three months of age. It causes a condition known as methemoglobinemia or "blue baby" disease. Water with nitrate levels exceeding 1.0 mg/L should not be used for feeding babies. High nitrates in drinking water can cause digestive disturbances in people. Nitrite/nitrogen levels below 90 mg/L and nitrate levels below 0.5 mg/L seem to have no affect on warm water fish. Because nitrogen is such an involved chemical, its consequences exceed simply water quality and extend to their consequences to organisms.

On one hand, you do not want nitrogenous compounds to rise too high.  Monitoring studies conducted at national and state levels show that nitrogen (N) concentrations in groundwater exceed health standards more often than other common contaminants, such as pesticides. A nationwide survey conducted by EPA showed that 1.2 percent of community and 2.4 percent of private drinking water wells exceeded the 10 parts per million (ppm) nitrate-nitrogen (NO3-N) standard. Though it rarely occurs, you also do not want nitrogen to drop too low. Nitrogen-containing compounds act as nutrients in streams, rivers, and reservoirs. Nitrite/nitrogen levels below 90 mg/L and nitrate levels below 0.5 mg/L seem to have no affect on warm water fish.

Nitrate and nitrite are compounds that contain a nitrogen atom joined to oxygen atoms, with nitrate containing three oxygen atoms and nitrite containing two. In nature, nitrates are readily converted to nitrites and vice versa. Both are anions, or ions with a negative charge. They tend to associate with cations, or ions with a positive charge, to achieve a neutral charge balance.Nitrates are naturally present in soil, water, and food. In the natural nitrogen cycle, bacteria convert nitrogen to nitrate, which is taken up by plants and incorporated into tissues. Animals that eat plants use the nitrate to produce proteins. Nitrate is returned to the environment in animal feces, as well as through microbial degradation of plants and animals after they die. Microorganisms can convert nitrate or the ammonium ion (which is a nitrogen atom combined with four hydrogen atoms) to nitrite; this reaction occurs in the environment as well as within the digestive tract of humans and other animals. After bacteria
convert (reduce) nitrate to nitrite in the environment, the nitrogen cycle is completed when they then convert the nitrite to nitrogen. Normally, this natural cycling process does not allow excessive amounts of nitrates or nitrites to accumulate in the environment. However, human activities have increased environmental nitrate concentrations, with agriculture being the major source. This includes increased use of nitrogen-containing fertilizers as well as concentrated livestock and poultry farming; the latter two produce millions of tons of nitrate-containing manure each year. Nitrate and nitrite compounds are very soluble in water and quite mobile in the environment. They have a high potential for entering surface water when it rains, as nitrates in applied fertilizers can dissolve in runoff that flows into streams or lakes; they also have a high potential for entering groundwater through leaching. The concentration associated with soil particles has been estimated to be about half the concentration in interstitial water (the water in the pore spaces between the soil particles).

Nitrates themselves are relatively nontoxic. However, when swallowed, they are converted to nitrites that can react with hemoglobin in the blood, oxidizing its divalent iron to the trivalent form and creating methemoglobin. This methemoglobin cannot bind oxygen, which decreases the capacity of the blood to transport oxygen so less oxygen is transported from the lungs to the body tissues, thus causing a condition known as methemoglobinemia. Normal individuals have low levels (0.5 to 2%) of methemoglobin in their blood. When this level increases to 10%, the skin and lips can take on a bluish tinge (cyanosis), and levels above 25% can cause weakness and a rapid pulse. At levels above 50 to 60%, a person can lose consciousness, go into a coma, and die. Infants are much more sensitive than adults to nitrates/nitrites, and essentially all deaths from nitrate/nitrite poisoning have been in infants. Long-term exposure to lower levels of nitrates and nitrites can cause diuresis (an increase in the amount of urine, and starchy deposits and hemorrhaging of the spleen).

Top 10 Amazing Extinct Animals

Industrial Dust, Air Pollution and related Occupational Diseases – Nuisance to be controlled for improvement of general environment, safety and health standard:

Industrial Dust, Air Pollution and related Occupational Diseases – Nuisance to be controlled for improvement of general environment, safety and health standard:

1.0. Introduction - Air pollution is the presence of high concentration of contamination, dust, smokes etc., in the general body of air man breaths. Dust is defined as particulate matter as “any airborne finely divided solid or liquid material with a diameter smaller than 100 micrometers.” Dust and smoke are the two major components of particulate matter. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it’s also called smog. These materials come from various sources, such as, various industrial processes, paved and unpaved roadways, construction and demolition sites, parking lots, storage piles, handling and transfer of materials, and open areas. Some air pollutants are poisonous. Inhaling them can increase the chances of health problems. In fact, dust when inhaled can increase breathing problems, damage lung tissue, and aggravate existing health problems. In addition to health concerns, dust generated from various activities can reduce visibility, resulting in accidents. Therefore, every federal Govt. has stringent regulations which require prevention, reduction and/or mitigation of dust emissions.
Thus, prime sources of air pollution are the industrial activities or processes releasing large quantity of pollutants in the atmosphere. These pollutants are mainly:
(a) Smoke comes out from various industries like, power plants, chemical plants, other manufacturing facilities, motor vehicles, etc.;
(b) Burning of wood, coal in furnaces and incinerators;
(c) Gaseous pollutants from Oil refining industries;
(d) Dust generated and thrown to general atmosphere by various industries such as cement plants, ore / stone crushing units, mining industries due to rock drilling & movements of mining machineries & blasting etc.;
(e) Waste deposition for landfills which generate methane;
(f) Toxic / germ / noxious gasses and fumes generated from military activities and explosives blasting in mines.

2.0. Mechanism of Adverse Impact of Smoke Pollutant – The main sources of smoke pollutants in urban areas are Petrol / Diesel driven motor vehicles, Fuel combustion in stationary sources including residential, commercial and industrial heating / cooling system and coal-burning power plants etc.
Petrol / Diesel driven motor vehicles produce high levels of Carbon Dioxide (CO2) / Carbon Monoxide (CO), major source of Hydrocarbon (HC) and Nitrogen oxides (NOx). Fuel combustion in stationary sources is the dominant source of Carbon Dioxide (CO2) and Sulfur Dioxide (SO2).
Carbon Dioxide (CO2)– This is one of the major gas pollutants in the atmosphere. Major sources of CO2 are due to burning of fossil fuels and deforestation. Industrially developed countries like USA, Russia etc., account for more than 65% of CO2 emission. Less developed countries with 80% of world’s population responsible for about 35% of CO2 emission. Due to high growth reported from less developed countries in last decade, it is estimated that, the Carbon dioxide emissions may rise from these areas and by 2020 their contribution may become 50%. It has also been seen that, Carbon dioxide emissions are rising by 4% annually.
As ocean water contain about 60 times more CO2 than atmosphere; CO2 released by the industry leads to disturbance of equilibrium of concentration of CO2 in the system. In such a scenario, the oceans would absorb more and more CO2 and atmosphere would also remain excess of CO2. As water warms, ocean’s ability to absorb CO2 is reduced. CO2 is a good transmitter of sunlight, but partially restricts infrared radiation going back from the earth into space. This produces the so-called “Greenhouse Effect” that prevents a drastic cooling of the Earth during the night. This so-called “Greenhouse Effect” is responsible for GLOBAL WARMING. Currently Carbon Dioxide is responsible for major portion of the global warming trend.
Nitrogen oxides (NOx)– They come mainly from nitrogen based fertilizers, deforestation, and biomass burning. Nitrogen oxides contribute mostly as atmospheric contaminants. These gases are responsible in the formation of both acid precipitation and photochemical smog and causes nitrogen loading. These gases have a role in reducing stratospheric ozone.
Sulfur Dioxide (SO2)– Sulfur dioxide is produced by combustion of sulfur-containing fuels, such as coal and fuel oils. SO2 also produced in the process of producing Sulfuric Acid and in metallurgical process involving ores that contain sulfur. Sulfur oxides can injure man, plants and materials. As emissions of sulfur dioxide and nitric oxide from stationary sources are transported long distances by winds, they form secondary pollutants such as nitrogen dioxide, nitric acid vapor, and droplets containing solutions of sulfuric acid, sulfate, and nitrate salts. These chemicals descend to the earth’s surface in wet form as rain or snow and in dry form as a gases fog, dew, or solid particles. This is known as acid deposition or acid rain.
Choloroflurocarbons (CFCs)– Chlorofluorocarbons, also known as Freons, are greenhouse gases that contribute to global warming. CFCs are responsible for lowering the average concentration of ozone in the stratosphere.
Smog – Smog is the result from the irradiation by sunlight of hydrocarbons caused primarily by unburned gasoline emitted by automobiles and other combustion sources. Smog is created by burning coal and heavy oil that contain mostly sulfur impurities.
[For more refer Pollution from Motor Vehicles ]

3.0. Mechanism of air pollution by particulate matters (Fine and Coarse Dust particles) – ‘Fine particles’ are less than 2.5 micron in size and require electron microscope for detection, however, they are much larger than the molecules of Ozone etc., and other gaseous pollutants, which are thousands times smaller and cannot be seen through even electron microscope.
Fine particles are formed by the condensation of molecules into solid or liquid droplets, whereas larger particles are mostly formed by mechanical breakdown of material or crushing of minerals. ‘Coarse particles’ are between 2.5 to 10 micron size, and cannot penetrate as readily as of Fine particle; however, it has been seen these are responsible for serious health hazards. The severity of the health hazards vary with the chemical nature of the particles.
The inhalation of particles has been linked with illness and deaths from heart and lung disease as a result of both short- and long-term exposures. People with heart and lung disease may experience chest pain, shortness of breath, fatigue etc., when exposed to particulate-matter pollutants. Inhalation of particulate matter can increase susceptibility to respiratory infections such as Asthma, Chronic Bronchitis. The general medical term given for such lung diseases is ‘Pneumoconiosis’.
Emissions from diesel-fuel combustion in vehicles / engines / equipments; Dusts from cement plants, power plants, chemical plants, mines are a special problem, specially for those individuals breathing in close proximity to such atmosphere. Cars, trucks and off-road engines emit more than half a million tones of diesel particulate matter per year.
3.1. Controlling Airborne Particulate Matters – Airborne particulate matters (PM) emissions can be minimized by pollution prevention and emission control measures. Prevention, which is frequently more cost-effective than control, should be emphasized. Special attention should be given to mitigate the effects, where toxics associated with particulate emissions may pose a significant environmental risk.
Measures such as improved process design, operation, maintenance, housekeeping, and other management practices can reduce emissions. By improving combustion efficiency in Diesel engines, generation of particulate matters can be significantly reduced. Proper fuel-firing practices and combustion zone configuration, along with an adequate amount of excess air, can achieve lower PICs (products of incomplete combustion). Few following steps should be adhered to control PM:
a. Choosing cleaner fuels – Natural gas used as fuel emits negligible amounts of particulate matter.
b. Low-ash fossil fuels contain less noncombustible, ash-forming mineral matter and thus generate lower levels of particulate emissions.
c. Reduction of ash by coal cleaning reduces the generation of ash and Particulate Matter (PM) emissions by up to 40%.
d. The use of more efficient technologies or process changes can reduce PIC emissions.
e. Advanced coal combustion technologies such as coal gasification and fluidized-bed combustion are examples of cleaner processes that may lower PICs by approximately 10%.
f. A variety of particulate removal technologies, are available – these are (a) Inertial or impingement separators, (b) Electrostatic precipitators (ESPs) , (c) Filters and dust collectors (baghouses), (d) Wet scrubbers that rely on a liquid spray to remove dust particles from a gas stream.
4.0. Dust in cement industry – Its prevention and collection enhances environment standard : The manufacturing of cement involves mining; crushing and grinding of raw materials (mostly limestone and clay); calcinating the material in rotary kiln; cooling the resulting clinker; mixing the clinker with Gypsum; and milling, storing and bagging the finished cement. The cement manufacturing process generates lot of dust, which is captured and recycled to the process. Gasses from clinker cooler are used as secondary combustion air. The process, using pre-heaters and pre-calciners, is both economically and environmentally preferable to wet process because of techno-economic advantages of the energy saving dry system over wet. Certain other solids such as pulverized fly ash from power plants, slag, roasted pyrite residue and foundry sand can be used as additives to prepare blended cement.
a. Dust generation: Generation of fine particulates and dust are inherent in the process; but most are recovered and recycled. The sources of dust emission include clinker cooler, crushers, grinders and material-handling equipments. Material-handling operations such as conveyors result in fugitive dust emission.
b. Prevention and control of dust: The priority in the cement industry is to minimize the increase in ambient particulate levels by reducing the mass load emitted from the stacks, from fugitive emissions, and from other sources. Collection and recycling of dust in the kiln gases in required to improve the efficiency of the operation and to reduce atmospheric emissions. Units that are well designed, well operated, and well maintained can normally achieve generation of less than 0.2 kilograms of dust per metric tonne (kg /t) of clinker, using dust recovery systems. For control of fugitive dust (a) ventilation systems should be used in conjunction with hoods and enclosures covering transfer points and conveyors; (b) Drop distances should be minimized by the use of adjustable conveyors; (c) Dusty areas such as roads should be wetted down to reduce dust generation; (d) Appropriate stormwater and runoff control systems should be provided to minimize the quantities of suspended material carried off site.
c. Mechanical systems for controlling dust:Several mechanical equipments are used in cement manufacturing plant to control / collect dust. These are:
(i) Dust collector - A dust collector (bag house) is a typically low strength enclosure that separates dust from a gas stream by passing the gas through a media filter. The dust is collected on either the inside or the outside of the filter. A pulse of air or mechanical vibration removes the layer of dust from the filter. This type of filter is typically efficient when particle sizes are in the 0.01 to 20 micron range.
(ii) Cyclone - Dust laden gas enters the chamber from a tangential direction at the outer wall of the device, forming a vortex as it swirls within the chamber. The larger articulates, because of their greater inertia, move outward and are forced against the chamber wall. Slowed by friction with the wall surface, they then slide down the wall into a conical dust hopper at the bottom of the cyclone. The cleaned air swirls upward in a narrower spiral through an inner cylinder and emerges from an outlet at the top. Accumulated particulate dust is deposited into a hopper, dust bin or screw conveyor at the base of the collector. Cyclones are typically used as pre-cleaners and are followed by more efficient air-cleaning equipment such as electrostatic precipitators and bag houses.
(iii) Electrostatic Precipitator - In an electrostatic precipitator, particles suspended in the air stream are given an electric charge as they enter the unit and are then removed by the influence of an electric field. A high DC voltage (as much as 100,000 volts) is applied to the discharge electrodes to charge the particles, which then are attracted to oppositely charged collection electrodes, on which they become trapped. An electrostatic precipitator can remove particulates as small as 1 μm (0.00004 inch) with an efficiency exceeding 99 percent.

5.0. Dust in Coal Handling Plant (CHP) and its control systems: Thermal power plants (coal-fired power plants) use coal as their fuel. To handle the coal, each power station is equipped with a coal handling plant. The coal has to be sized, processed, and handled which should be done effectively and efficiently. The major factor which reduces the staff efficiency in operation of coal handling plant is the working environment i.e. a dusty atmosphere and condition. Lots of care is always needed to reduce dust emission. In developing countries, all most all systems used in power station coal handling plants are wet dust suppression systems.
5.1. After dust is formed, control systems are used to reduce dust emissions. Although installing a dust control system does not assure total prevention of dust emissions, a well-designed dust control system can protect workers and often provide other benefits, such as (a) Preventing or reducing risk of dust explosion or fire; (b) Increasing visibility and reducing probability of accidents; (c) Preventing unpleasant odors; (d) Reducing cleanup and maintenance costs; (e) Reducing equipment wear, especially for components such as bearings and pulleys on which fine dust can cause a “grinding” effect and increase wear or abrasion rates; (f) Increasing worker morale and productivity; (f) Assuring continuous compliance with existing health regulations. In addition, proper planning, design, installation, operation, and maintenance are essential for an efficient, cost-effective, and reliable dust control system.
5.2. There are two basic types of dust control systems currently used in minerals processing operations are:
(a) Dust collection system - Dust collection systems use ventilation principles to capture the dust-filled air-stream and carry it away from the source through ductwork to the collector. A typical dust collection system consists of four major components, such as (1) An exhaust hood to capture dust emissions at the source; (2) Ductwork to transport the captured dust to a dust collector; (3) A dust collector to remove the dust from the air; (4) A fan and motor to provide the necessary exhaust volume and energy.
(b) Wet dust suppression system - Wet dust suppression techniques use water sprays to wet the material so that it generates less dust. There are two different types of wet dust suppression:
(i) wets the dust before it is airborne (surface wetting) and
(ii) wets the dust after it becomes airborne. In many cases surfactants or chemical foams are often added to the water into these systems in order to improve performance.
A water spray with surfactant means that a surfactant has been added to the water in order to lower the surface tension of the water droplets and allow these droplets to spread further over the material and also to allow deeper penetration into the material.
i. Surface wetting system: The principle behind surface wetting is the idea that dust will not even be given a chance to form and become airborne. With this method, effective wetting of the material can take place by static spreading (wetting material while it is stationary) and dynamic spreading (wetting material while it is moving). For static wetting, more effective dust suppression arises by increasing the surface coverage by either reducing the droplet diameter or its contact angle. For dynamic spreading, more factors come into play such as the surface tension of the liquid, the droplet diameter, the size of the material being suppressed, and the droplet impact velocity.
ii. Airborne dust capture system - Airborne dust capture systems may also use a water-spray technique; however, airborne dust particles are sprayed with atomized water. When the dust particles collide with the water droplets, agglomerates are formed.  These agglomerates become too heavy to remain airborne and settle. Airborne dust wet suppression systems work on the principle of spraying very small water droplets into airborne dust. When the small droplets collide with the airborne dust particles, they stick to each other and fall out of the air to the ground. Research showed that, if a sufficient number of water droplets of approximately the same size as the dust particles could be produced, the possibility of collision between the two would be extremely high. It was also determined that if the droplet exceeded the size of the dust particle, there was little probability of impact and the desired precipitation. Instead, the dust particle would move around the droplet.
5.3. System Efficiency: Over the years, water sprays has established the following facts:
(a) For a given spray nozzle, the collection efficiency for small dust particles increases as the pressure increases;
(b) At a given pressure, the efficiency increases as the nozzle design is changed so as to produce smaller droplets. The efficiency of spray dust capture increases by increasing the number of smaller sized spray droplets per unit volume of water utilized and by optimizing the energy transfer of spray droplets with the dust-laden air.
5.4. Sophisticated system like ‘Ultrasonic Dust Suppression’ systems uses water and compressed air to produce micron sized droplets that are able to suppress respirable dust without adding any detectable moisture to the process. Ideal for spray curtains to contain dust within hoppers. The advantages of using Ultrasonic Atomizing Systems for dust suppression can therefore be summarized as: (a) reduced health hazards; (b) decrease in atmospheric pollution; (c) improved working conditions; (d) efficient operation with minimum use of water.

6.0. Air pollution control devices / equipments for industries, in general – The commonly used equipments / process for control of dust in various industries are (a) Mechanical dust collectors in the form of dust cyclones; (b) Electrostatic precipitators – both dry and wet system; (c) particulate scrubbers; (d) Water sprayer at dust generation points; (e) proper ventilation system and (f) various monitoring devices to know the concentration of dust in general body of air.
The common equipments / process used for control of toxic / flue gases are the (a) process of desulphurisation; (b) process of denitrification; (c) Gas conditioning etc. and (d) various monitoring devices to know the efficacy of the systems used.
7.0. Occupational Hazards / diseases due to expose in dusty and polluted air: There are certain diseases which are related to one’s occupation. These are caused by constant use of certain substances that sneak into air and then enter our body.
(i) Silicosis (Silico-tuberculosis) occurs due to inhalation of free silica, or SiO2 (Silicon dioxide), while mining or working in industries related to pottery, ceramic, glass, building and construction work. The workers get chronic cough and pain in the chest. Silicosis treatment is extremely limited considering a lack of cure for the disease. However, like all occupational respiratory ailments, it is 100% preventable if exposure is minimized.
(ii) Asbestosis is caused by asbestos, which is used in making ceilings. It is also considered as cancer causing agent. Pathogenesis of the disease is characterized as progressive and irreversible, leading to subsequent respiratory disability. In severe cases, asbestosis results in death from pulmonary hypertension and cardiac failure.
(iii) Byssinosis, also referred to as brown lung disease, is an occupational respiratory disorder characterized by the narrowing of pulmonary airways. It is a disabling lung disease, which is marked by chronic cough and chronic bronchitis due to inhalation of cotton fibers over a long period of time.
(iv) Coal worker’s Pneumoconiosis occurs due to inhalation of coal dust from coal mining industry. Also referred to as black lung disease. The workers suffer from lung problems. Apart from asbestosis, black lung disease is the most frequently occurring type of pneumoconiosis . In terms of disease pathogenesis, a time delay of nearly a decade or more occurs between exposure and disease onset.
7.1. Preventive Measures – The most successful tool of prevention of respiratory diseases from industrial dust is to minimize exposure. However, this is not a practical approach from the perspective of industries such as mining, construction/demolition, refining/manufacturing/processing, where industrial dust is an unavoidable byproduct. In such cases, industries must implement a stringent safety protocol that effectively curtails exposure to potentially hazardous dust sources. National Institute for Occupational Safety and Health (NIOSH) recommended precautionary measures to reduce exposure to a variety of industrial dust types.
1.    Recognize when industrial dust may be generated and plan ahead to eliminate or control the dust at the source. Awareness and planning are keys to prevention of silicosis.
2.    Do not use silica sand or other substances containing more than 1% crystalline silica as abrasive blasting materials. Substitute less hazardous materials.
3.    Use engineering controls and containment methods such as blast-cleaning machines and cabinets, wet drilling, or wet sawing of silica-containing materials to control the hazard and protect adjacent workers from exposure.
4.    Routinely maintain dust control systems to keep them in good working order.
5.    Practice good personal hygiene to avoid unnecessary exposure to other worksite contaminants such as lead.
6.    Wear disposable or washable protective clothes at the worksite.
7.    Shower (if possible) and change into clean clothes before leaving the worksite to prevent contamination of cars, homes, and other work areas.
8.    Conduct air monitoring to measure worker exposures and ensure that controls are providing adequate protection for workers.
9.    Use adequate respiratory protection when source controls cannot keep silica exposures below the designated limit.
10.    Provide periodic medical examinations for all workers who may be exposed to respirable crystalline silica.
11.    Post warning signs to mark the boundaries of work areas contaminated with respirable crystalline silica.
12    Provide workers with training that includes information about health effects, work practices, and protective equipment for respirable crystalline silica.
13.    Report all cases of silicosis to Federal / State health departments.
8.0. Preventing damaging effects of air and dust pollution – The prevention of air pollution is world wide concern. There have been many investigations into what causes air pollution and the exact methods that work best in the prevention of air pollution. Through the use of many different methods air pollution is becoming easier to control. It is only through various measures, though, that the prevention of air pollution is possible. The government plays a very important role in prevention of air pollution. It is through government regulations that industries are forced to reduce their air pollution and new developments in technology are created to help everyone do their part in the prevention of air pollution. The government also helps by continuously making regulations stricter and enforcing new regulations that help to combat any new found source of air pollution.
In many countries in the world, steps are being taken to stop the damage to our environment from air pollution. Scientific groups study the damaging effects on plant, animal and human life. Legislative bodies write laws to control emissions. Educators in schools and universities teach students, beginning at very young ages, about the effects of air pollution. The first step to solving air pollution is assessment. Researchers have investigated outdoor air pollution and have developed standards for measuring the type and amount of some serious air pollutants.
Scientists must then determine how much exposure to pollutants is harmful. Once exposure levels have been set, steps can be undertaken to reduce exposure to air pollution. These can be accomplished by regulation of man-made pollution through legislation. Many countries have set controls on pollution emissions for transportation vehicles and industry. This is usually done to through a variety of coordinating agencies which monitor the air and the environment.
In the prevention of air pollution it is important to understand about indoor air pollution. Indoor air pollution may seem like an individual concern, but it actually is not just something to worry about in your own home. Indoor air pollution contributes to outdoor air pollution. Prevention is another key to controlling air pollution. The regulatory agencies mentioned above play an essential role in reducing and preventing air pollution in the environment. In addition, it is possible to prevent many types of air pollution that are not regulated through personal, careful attention to our interactions with the environment. One of the most dangerous indoor air pollutants is cigarette smoke. Restricting smoking is an important key to a healthier environment. Legislation to control smoking is in effect in some locations, but personal exposure should be monitored and limited wherever possible.
9.0. Conclusion – Air pollution prevention efforts of companies have generally focused on both source and waste reduction, and on reuse and recycling. Preventing air pollution within a company’s manufacturing processes remains the key approach. Cleaning and processing, switch to non-polluting technologies and materials, reduced generation of waste water, converting hazardous by-products to non-threatening forms, etc. have been attempted in this regard. Indirect air pollution prevention measures by companies also cover transportation. Examples of such measures include: providing company transportation to employees; offering commuting information and selling public transit passes; and encouraging employees to carpool and use public transportation. Companies have also initiated successful programmes such as the use of bicycles to commute to work, telecomuting, and work-at-home etc. to reduce pollution due to commuting.
It should be noted that, only through the efforts of scientists, business leaders, legislators, and individuals can we reduce the amount of air pollution on the planet. This challenge must be met by all of us in order to assure that a healthy environment exist for ourselves and our children.

Did pilot commit SUICIDE? CIA boss says it is one theory agency is looking at as Malaysian police say they are carrying out psychological profiles of everyone on plane

• CIA head John Brennan: 'No theory can be discounted' in hunt for clues
• It came after he was asked if it was possible the pilot deliberately crashed
• Brennan also said 'terrorism has not yet been ruled out of investigation'
• Malaysian police say one of the two men on stolen passports was Iranian
• Was asylum seeker, 19, 'not terrorist', and his mother was waiting for him
• Smartphones of missing aboard flight MH370 'are still ringing', families say
• 19 families of missing claim to be connected - airline have also called crew
• Growing frustration for relatives with no information on their missing
• Angry relatives threw water bottles at officials unable to offer any answers

Frustrated relatives of Chinese passengers threw water bottles at airline officials during briefing

India grows, environment pays the cost

India has driven the truck of development — loaded with tar, bricks, glass, concrete…the works — right through its most treasured and fragile green spaces in the last decade. While major cities like Delhi and Mumbai sacrificed green cover for real estate, the country's finest wildlife corridors have been ceded to indiscriminate industrialisation.

In the absence of a clear policy to balance development and environment, the Aravallis in Gurgaon, Western Ghats spread across five states, biodiversity of the Northeast and the forests in tribal districts (one-fifth of the country’s 640 districts) have taken a hit.
India lost 135 hectares of forest — think 190 full-sized football fields — daily to industrial projects in 2013 compared with about 80 hectare two decades ago, showed an RTI reply by the environment ministry.

Nothing will change unless environement protection is made independent of the government, say environmentalists (HT photo)

The government records, however, fail to depict the true degradation, thanks to Forest Survey of India (FSI) showing rubber plantations and apple orchards as green cover. “The trick is that the forest department manages to add compensatory afforestation programmes to the total green cover,” said Neeraj Vagholikar of environmental group Kalpavriksh.
Western Ghats’ forests — spread across Gujarat, Maharashtra, Karnataka, Andhra Pradesh and Kerala — shrunk by about 25% in two decades because of reckless mining and quarrying.
Stalin D of environmental group Vanashakti said the government had meekly surrendered to the “development lobby which sought a free hand to unleash destruction”. Madhav Gadgil, who headed an ecological expert panel on the Western Ghats, said if restrictions were not imposed, we would lose pristine ecology to “those who send bags of money to politicians”.
In spite of a 2005 Bombay high court order declaring mangroves as forests, rampant reclamation of mangrove-rich coasts is making way for housing projects and industries in Maharashtra.
In the Northeast, a probe panel set up by the Supreme Court in 2011 found that 39% land at nine cement plants in Meghalaya were forests. Around 10,000 hectares of forest has been encroached by tea estates in Assam.
About 80 hydel projects in Arunachal Pradesh approved in the last three years would wipe out hundreds of acres of forest including the habitat of the Black Neck Crane, considered the embodiment of the sixth Dalai Lama, and the Bengal Florican, a critically endangered species.
Northeast’s jewel, the Kaziranga National Park, home to tigers and the single-horn rhino, has been damaged by stone quarries, stone crushes, brick kilns and other industrial units within the notified ‘no development zone’.
“The environment ministry and the Assam government allowed the mushrooming of industrial units including private tea factories in this sensitive zone,” said Rohit Choudhury, an activist who lives near Kaziranga.
Elsewhere, it is the same story.
Odisha, Jharkhand, Chhattisgarh and Goa have all lost green cover to aggressive mining. The MB Shah Commission, which investigated illegal mining in these states, accused the environment ministry of allowing plunder at the cost of the exchequer.
In Odisha alone, the panel said, illegal mining worth Rs. 59,000 crore was allowed. Around 16,000 hectare of forest — half of it in Keonjhar district — was lost to mining. Odisha principal chief conservator of forest JD Sharma, however, said there was no violation.
“When we find any discrepancy, we initiate action,” he said.
Among more than 100 projects cleared, environment minister Veerappa Moily this February allowed mining in the core area of an elephant reserve in Jharkhand. Earlier, the ministry approved mining in the green corridor used by elephants and tigers to move from one reserve to another in Maharashtra and Chhattisgarh.
Forest loss because of rampant mining had prompted Tribal Affairs minister V Kishore Chandra Deo to seek a ban on mining in tribal areas including in his home state Andhra Pradesh, where about 1,500 hectares in Visakhapatnam cleared for bauxite mining is under litigation.
“Mining clearances are being given without a thorough environmental and social impact assessment. This leads to rapid forest degradation and unrest among local tribals dependent on these forests for their livelihood,” said Srinivas Ganjivarapu, environmental activist based in Visakhapatnam.
Closer home in Delhi, green regulations are getting compromised within 40 km of the ministry’s headquarters at Paryavaran Bhawan.
The National Capital Region Planning Board plans to allow 0.5% of Aravallis for construction and tourism on the ground of land constraint, by leasing the capital’s green lungs to colonisers. The state had sought permission from courts to set up a Disneyland, a technology park and a film city. The courts refused permission.
In UP, sand mining and unauthorised construction on Yamuna banks goes on unabated, resulting in shrinking of wetlands from 19 in 2009 to 6 in 2011. “Ironic that a state, which is willing to spend Rs. 2,000 crore on an artificial night zoo, is not protecting its natural gifts,” said Vikrant Tongad, a local environmentalist.An officer like Durga Shakti Nagpal, who challenged the mining mafia, was suspended in 2013 for stopping illegal sand mining in Gautam Budh Nagar. A young IPS officer, Narendra Kumar Singh, was crushed under a tractor in MP’s Morena in 2012 when he tried stopping illegal sand mining.
“Nothing much will change unless environment protection is made independent of the government. There needs to be transparency in clearing projects and strict penalties for violation,” said Sunita Narian, director general of Delhi-based advocacy group Centre for Science and Environment.
(With inputs from Prasad Nichenametla, Rahul Karmakar, Priyaranjan Sahu, Vinod Rajput and Snehil Sinha)

History of Kakinada

Etymology

Geography

Distances to other cities in Andhra Pradesh:

Climate

Civic Administration

Transportation

Air

Rail

Road

Economy

Kakinada Port

Industries

Fertilizer

Sugar

Natural Gas and Petroleum

Edible Oil Refineries and Biofuel Plants

Power Generation

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City

Retails, Entertainment and Attractions

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Merger of Villages:

Tourism

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People

Notable Residents

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(a) identification of relevant data regarding the hazards of a chemical;

(b) subsequent review of those data to ascertain the hazards associated with the chemical;

(c) determination of whether the chemical will be classified as hazardous and the degree of hazard.

(a) Where test data are available for the complete mixture, the classification of the mixture will always be based on those data;

(b) Where test data are not available for the mixture itself, the bridging principles designated in each health hazard chapter of this appendix shall be considered for classification of the mixture;

(c) If test data are not available for the mixture itself, and the available information is not sufficient to allow application of the above-mentioned bridging principles, then the method(s) described in each chapter for estimating the hazards based on the information known will be applied to classify the mixture (e.g., application of cut-off values/concentration limits).

(a) the new diluted mixture shall be classified as equivalent to the original tested mixture; or

(b) for classification of acute toxicity in accordance with A.1 of this Appendix, paragraph A.1.3.6 (the additivity formula) shall be applied.

(a) Where there are two mixtures: (i) A + B;
(ii) C + B;

(b) the concentration of ingredient B is essentially the same in both mixtures;

(c) the concentration of ingredient A in mixture (i) equals that of ingredient C in mixture (ii);

(d) and data on toxicity for A and C are available and substantially equivalent; i.e., they are in the same hazard category and are not expected to affect the toxicity of B; then

(a) The acute toxicity estimate (ATE) for the classification of a substance is derived using the LD₅₀/LC₅₀ where available;

(b) The acute toxicity estimate (ATE) for the classification of a substance or ingredient in a mixture is derived using:

(i) the LD₅₀/LC₅₀ where available. Otherwise,

(ii) the appropriate conversion value from Table 1.2 that relates to the results of a range test, or

(iii) the appropriate conversion value from Table 1.2 that relates to a classification category;

(c) Inhalation cut-off values in the table are based on 4 hour testing exposures. Conversion of existing inhalation toxicity data which has been generated according to 1 hour exposure is achieved by dividing by a factor of 2 for gases and vapors and 4 for dusts and mists;

(d) For some substances the test atmosphere will be a vapor which consists of a combination of liquid and gaseous phases. For other substances the test atmosphere may consist of a vapor which is nearly all the gaseous phase. In these latter cases, classification is based on ppmV as follows: Category 1 (100 ppmV), Category 2 (500 ppmV), Category 3 (2500 ppmV), Category 4 (20000 ppmV).

The terms "dust", "mist" and "vapor" are defined as follows:

(i) Dust: solid particles of a substance or mixture suspended in a gas (usually air);

(ii) Mist: liquid droplets of a substance or mixture suspended in a gas (usually air);

(iii) Vapor: the gaseous form of a substance or mixture released from its liquid or solid state.

(a) The "relevant ingredients" of a mixture are those which are present in concentrations ≥ 1% (weight/weight for solids, liquids, dusts, mists and vapors and volume/volume for gases). If there is reason to suspect that an ingredient present at a concentration < 1% will affect classification of the mixture for acute toxicity, that ingredient shall also be considered relevant. Consideration of ingredients present at a concentration < 1% is particularly important when classifying untested mixtures which contain ingredients that are classified in Category 1 and Category 2;

(b) Where a classified mixture is used as an ingredient of another mixture, the actual or derived acute toxicity estimate (ATE) for that mixture is used when calculating the classification of the new mixture using the formulas in A.1.3.6.1 and A.1.3.6.2.4.

(c) If the converted acute toxicity point estimates for all ingredients of a mixture are within the same category, then the mixture should be classified in that category.

(d) When only range data (or acute toxicity hazard category information) are available for ingredients in a mixture, they may be converted to point estimates in accordance with Table A.1.2 when calculating the classification of the new mixture using the formulas in A.1.3.6.1 and A.1.3.6.2.4.

The acute toxicity estimate (ATE) of ingredients is considered as follows:

(a) Include ingredients with a known acute toxicity, which fall into any of the acute toxicity categories, or have an oral or dermal LD50 greater than 2000 but less than or equal to 5000 mg/kg body weight (or the equivalent dose for inhalation);

(b) Ignore ingredients that are presumed not acutely toxic (e.g., water, sugar);

(c) Ignore ingredients if the data available are from a limit dose test (at the upper threshold for Category 4 for the appropriate route of exposure as provided in Table A.1.1) and do not show acute toxicity.

where:
Ci   =   concentration of ingredient i
n ingredients and i is running from 1 to n
ATEi   =   acute toxicity estimate of ingredient i.

(a) Extrapolation between oral, dermal and inhalation acute toxicity estimates. Such an evaluation requires appropriate pharmacodynamic and pharmacokinetic data;

(b) Evidence from human exposure that indicates toxic effects but does not provide lethal dose data;

(c) Evidence from any other toxicity tests/assays available on the substance that indicates toxic acute effects but does not necessarily provide lethal dose data; or

(d) Data from closely analogous substances using structure/activity relationships.

1. Evidence of existing human or animal data may be derived from single or repeated exposure(s) in occupational, consumer, transportation, or emergency response scenarios; from ethically-conducted human clinical studies; or from purposely-generated data from animal studies conducted according to scientifically validated test methods (at present, there is no internationally accepted test method for human skin irritation testing).
   
2. Classify in the appropriate harmonized category, as shown in Tables A.2.1 and A.2.2.
   
3. Pre-existing animal data (e.g. from an acute dermal toxicity test or a sensitisation test) should be carefully reviewed to determine if sufficient skin corrosion/irritation evidence is available through other, similar information. For example, classification/categorization may be done on the basis of whether a chemical has or has not produced any skin irritation in an acute dermal toxicity test in animals at the limit dose, or produces very toxic effects in an acute dermal toxicity test in animals. In the latter case, the chemical would be classified as being very hazardous by the dermal route for acute toxicity, and it would be moot whether the chemical is also irritating or corrosive on the skin. It should be kept in mind in evaluating acute dermal toxicity information that the reporting of dermal lesions may be incomplete, testing and observations may be made on a species other than the rabbit, and species may differ in sensitivity in their responses.
   
4. Evidence from studies using scientifically validated protocols with isolated human/animal tissues or other, non-tissue-based, though scientifically validated, protocols should be assessed. Examples of scientifically validated test methods for skin corrosion include OECD TG 430 (Transcutaneous Electrical Resistance Test (TER)), 431 (Human Skin Model Test), and 435 (Membrane Barrier Test Method). OECD TG 439 (Reconstructed Human Epidermis Test Method) is a scientifically validated in vitro test method for skin irritation.
   
5. Measurement of pH alone may be adequate, but assessment of acid or alkali reserve (buffering capacity) would be preferable. Presently, there is no scientifically validated and internationally accepted method for assessing this parameter.
   
6. All information that is available on a chemical should be considered and an overall determination made on the total weight of evidence. This is especially true when there is conflict in information available on some parameters. Professional judgment should be exercised in making such a determination.
   

(a) Respiratory sensitization; and

(b) Skin sensitization

(a) the size of the population exposed;

(b) the extent of exposure.

(a) clinical history and data from appropriate lung function tests related to exposure to the substance, confirmed by other supportive evidence which may include:

(i) in vivo immunological test (e.g., skin prick test);

(ii) in vitro immunological test (e.g., serological analysis);

(iii) studies that may indicate other specific hypersensitivity reactions where immunological mechanisms of action have not been proven, e.g., repeated low-level irritation, pharmacologically mediated effects;

(iv) a chemical structure related to substances known to cause respiratory hypersensitivity;

(b) data from positive bronchial challenge tests with the substance conducted according to accepted guidelines for the determination of a specific hypersensitivity reaction.

(a) measurements of Immunoglobulin E (IgE) and other specific immunological parameters, for example in mice

(b) specific pulmonary responses in guinea pigs.

(a) positive responses at ≤ 500 µg/cm² (Human Repeat Insult Patch Test (HRIPT), Human Maximization Test (HMT) – induction threshold);

(b) diagnostic patch test data where there is a relatively high and substantial incidence of reactions in a defined population in relation to relatively low exposure;

(c) other epidemiological evidence where there is a relatively high and substantial incidence of allergic contact dermatitis in relation to relatively low exposure.

(a) positive responses at > 500 µg/cm² (HRIPT, HMT – induction threshold);

(b) diagnostic patch test data where there is a relatively low but substantial incidence of reactions in a defined population in relation to relatively high exposure;

(c) other epidemiological evidence where there is a relatively low but substantial incidence of allergic contact dermatitis in relation to relatively high exposure.

(a) Positive data from patch testing, normally obtained in more than one dermatology clinic;

(b) Epidemiological studies showing allergic contact dermatitis caused by the substance. Situations in which a high proportion of those exposed exhibit characteristic symptoms are to be looked at with special concern, even if the number of cases is small;

(c) Positive data from appropriate animal studies;

(d) Positive data from experimental studies in man (See paragraph A.0.2.6 of this Appendix);

(e) Well documented episodes of allergic contact dermatitis, normally obtained in more than one dermatology clinic;

(f) Severity of reaction.

(a) Isolated episodes of allergic contact dermatitis;

(b) Epidemiological studies of limited power, e.g., where chance, bias or confounders have not been ruled out fully with reasonable confidence;

(c) Data from animal tests, performed according to existing guidelines, which do not meet the criteria for a positive result described in A.4.2.2.3, but which are sufficiently close to the limit to be considered significant;

(d) Positive data from non-standard methods;

(e) Positive results from close structural analogues.

(a) Rodent dominant lethal mutation test (OECD 478)

(b) Mouse heritable translocation assay (OECD 485)

(c) Mouse specific locus test

(a) Mammalian bone marrow chromosome aberration test (OECD 475)

(b) Mouse spot test (OECD 484)

(c) Mammalian erythrocyte micronucleus test (OECD 474)

(a) Mutagenicity tests:

(i) Mammalian spermatogonial chromosome aberration test (OECD 483)

(ii) Spermatid micronucleus assay

(b) Genotoxicity tests:

(i) Sister chromatid exchange analysis in spermatogonia

(ii) Unscheduled DNA synthesis test (UDS) in testicular cells

(a) Liver Unscheduled DNA Synthesis (UDS) in vivo (OECD 486)

(b) Mammalian bone marrow Sister Chromatid Exchanges (SCE)

(a) In vitro mammalian chromosome aberration test (OECD 473)

(b) In vitro mammalian cell gene mutation test (OECD 476)

(c) Bacterial reverse mutation tests (OECD 471)

(a) Tumor type and background incidence;

(b) Multisite responses;

(c) Progression of lesions to malignancy;

(d) Reduced tumor latency;

Additional factors which may increase or decrease the level of concern include:

(e) Whether responses are in single or both sexes;

(f) Whether responses are in a single species or several species;

(g) Structural similarity or not to a substance(s) for which there is good evidence of carcinogenicity;

(h) Routes of exposure;

(i) Comparison of absorption, distribution, metabolism and excretion between test animals and humans;

(j) The possibility of a confounding effect of excessive toxicity at test doses; and,

(k) Mode of action and its relevance for humans, such as mutagenicity, cytotoxicity with growth stimulation, mitogenesis, immunosuppression.

(a) Maternal mortality: An increased incidence of mortality among the treated dams over the controls shall be considered evidence of maternal toxicity if the increase occurs in a dose-related manner and can be attributed to the systemic toxicity of the test material. Maternal mortality greater than 10% is considered excessive and the data for that dose level shall not normally be considered to need further evaluation.

(b) Mating index (Number of animals with seminal plugs or sperm/Number of mated x 100)

(c) Fertility index (Number of animals with implants/Number of matings x 100)

(d) Gestation length (If allowed to deliver)

(e) Body weight and body weight change: Consideration of the maternal body weight change and/or adjusted (corrected) maternal body weight shall be included in the evaluation of maternal toxicity whenever such data are available. The calculation of an adjusted (corrected) mean maternal body weight change, which is the difference between the initial and terminal body weight minus the gravid uterine weight (or alternatively, the sum of the weights of the fetuses), may indicate whether the effect is maternal or intrauterine. In rabbits, the body weight gain may not be a useful indicator of maternal toxicity because of normal fluctuations in body weight during pregnancy.

(f) Food and water consumption (if relevant): The observation of a significant decrease in the average food or water consumption in treated dams (mothers) compared to the control group may be useful in evaluating maternal toxicity, particularly when the test material is administered in the diet or drinking water. Changes in food or water consumption must be evaluated in conjunction with maternal body weights when determining if the effects noted are reflective of maternal toxicity or more simply, unpalatability of the test material in feed or water.

(g) Clinical evaluations (including clinical signs, markers, and hematology and clinical chemistry studies): The observation of increased incidence of significant clinical signs of toxicity in treated dams (mothers) relative to the control group is useful in evaluating maternal toxicity. If this is to be used as the basis for the assessment of maternal toxicity, the types, incidence, degree and duration of clinical signs shall be reported in the study. Clinical signs of maternal intoxication include, but are not limited to: coma, prostration, hyperactivity, loss of righting reflex, ataxia, or labored breathing.

(h) Post-mortem data: Increased incidence and/or severity of post-mortem findings may be indicative of maternal toxicity. This can include gross or microscopic pathological findings or organ weight data, including absolute organ weight, organ to body weight ratio, or organ to brain weight ratio. When supported by findings of adverse histopathological effects in the affected organ(s), the observation of a significant change in the average weight of suspected target organ(s) of treated dams (mothers), compared to those in the control group, may be considered evidence of maternal toxicity.

(a) Morbidity resulting from single exposure;

(b) Significant functional changes, more than transient in nature, in the respiratory system, central or peripheral nervous systems, other organs or other organ systems, including signs of central nervous system depression and effects on special senses (e.g., sight, hearing and sense of smell);

(c) Any consistent and significant adverse change in clinical biochemistry, hematology, or urinalysis parameters;

(d) Significant organ damage that may be noted at necropsy and/or subsequently seen or confirmed at microscopic examination;

(e) Multi-focal or diffuse necrosis, fibrosis or granuloma formation in vital organs with regenerative capacity;

(f) Morphological changes that are potentially reversible but provide clear evidence of marked organ dysfunction; and,

(g) Evidence of appreciable cell death (including cell degeneration and reduced cell number) in vital organs incapable of regeneration.

(a) Clinical observations or small changes in bodyweight gain, food consumption or water intake that may have some toxicological importance but that do not, by themselves, indicate "significant" toxicity;

(b) Small changes in clinical biochemistry, hematology or urinalysis parameters and/or transient effects, when such changes or effects are of doubtful or of minimal toxicological importance;

(c) Changes in organ weights with no evidence of organ dysfunction;

(d) Adaptive responses that are not considered toxicologically relevant; and,

(e) Substance-induced species-specific mechanisms of toxicity, i.e., demonstrated with reasonable certainty to be not relevant for human health, shall not justify classification.

(a) Respiratory irritant effects (characterized by localized redness, edema, pruritis and/or pain) that impair function with symptoms such as cough, pain, choking, and breathing difficulties are included. It is recognized that this evaluation is based primarily on human data;

(b) Subjective human observations supported by objective measurements of clear respiratory tract irritation (RTI) (e.g., electrophysiological responses, biomarkers of inflammation in nasal or bronchoalveolar lavage fluids);

(c) The symptoms observed in humans shall also be typical of those that would be produced in the exposed population rather than being an isolated idiosyncratic reaction or response triggered only in individuals with hypersensitive airways. Ambiguous reports simply of "irritation" should be excluded as this term is commonly used to describe a wide range of sensations including those such as smell, unpleasant taste, a tickling sensation, and dryness, which are outside the scope of classification for respiratory tract irritation;

(d) There are currently no scientifically validated animal tests that deal specifically with RTI; however, useful information may be obtained from the single and repeated inhalation toxicity tests. For example, animal studies may provide useful information in terms of clinical signs of toxicity (dyspnoea, rhinitis etc) and histopathology (e.g., hyperemia, edema, minimal inflammation, thickened mucous layer) which are reversible and may be reflective of the characteristic clinical symptoms described above. Such animal studies can be used as part of weight of evidence evaluation; and,

(e) This special classification will occur only when more severe organ effects including the respiratory system are not observed as those effects would require a higher classification.

(a) Central nervous system depression including narcotic effects in humans such as drowsiness, narcosis, reduced alertness, loss of reflexes, lack of coordination, and vertigo are included. These effects can also be manifested as severe headache or nausea, and can lead to reduced judgment, dizziness, irritability, fatigue, impaired memory function, deficits in perception and coordination, reaction time, or sleepiness; and,

(b) Narcotic effects observed in animal studies may include lethargy, lack of coordination righting reflex, narcosis, and ataxia. If these effects are not transient in nature, then they shall be considered for classification as Category 1 or 2.

(a) Morbidity or death resulting from repeated or long-term exposure. Morbidity or death may result from repeated exposure, even to relatively low doses/concentrations, due to bioaccumulation of the substance or its metabolites, or due to the overwhelming of the de-toxification process by repeated exposure;

(b) Significant functional changes in the central or peripheral nervous systems or other organ systems, including signs of central nervous system depression and effects on special senses (e.g., sight, hearing and sense of smell);

(c) Any consistent and significant adverse change in clinical biochemistry, hematology, or urinalysis parameters;

(d) Significant organ damage that may be noted at necropsy and/or subsequently seen or confirmed at microscopic examination;

(e) Multi-focal or diffuse necrosis, fibrosis or granuloma formation in vital organs with regenerative capacity;

(f) Morphological changes that are potentially reversible but provide clear evidence of marked organ dysfunction (e.g., severe fatty change in the liver); and,

(g) Evidence of appreciable cell death (including cell degeneration and reduced cell number) in vital organs incapable of regeneration.

(a) Clinical observations or small changes in bodyweight gain, food consumption or water intake that may have some toxicological importance but that do not, by themselves, indicate "significant" toxicity;

(b) Small changes in clinical biochemistry, hematology or urinalysis parameters and /or transient effects, when such changes or effects are of doubtful or of minimal toxicological importance;

(c) Changes in organ weights with no evidence of organ dysfunction;

(d) Adaptive responses that are not considered toxicologically relevant;

(e) Substance-induced   species-specific   mechanisms   of   toxicity,   i.e., demonstrated with reasonable certainty to be not relevant for human health, shall not justify classification.

[77 FR 17790, March 26, 2012; 78 FR 9313, Feb. 8, 2013]