Cadmium is an extremely toxic metal commonly found in industrial workplaces. Due to its low permissible exposure limit, overexposures may occur even in situations where trace quantities of cadmium are found. Cadmium is used extensively in electroplating, although the nature of the operation does not generally lead to overexposures. Cadmium is also found in some industrial paints and may represent a hazard when sprayed. Operations involving removal of cadmium paints by scraping or blasting may pose a significant hazard. Cadmium is also present in the manufacturing of some types of batteries. Exposures to cadmium are addressed in specific standards for the general industry, shipyard employment, construction industry, and the agricultural industry.
Mercury poisoning is a disease caused by exposure to mercury or its compounds. Mercury (chemical symbol Hg) is a heavy metal occurring in several forms, all of which can produce toxic effects in high enough doses. Its zero oxidation stateHg0 exists as vapor or as liquid metal, its mercurous state Hg22+ exists as inorganic salts, and its mercuric state Hg2+ may form either inorganic salts or organomercury compounds; the three groups vary in effects. Toxic effects include damage to the brain, kidney, and lungs. Mercury poisoning can result in several diseases, including acrodynia (pink disease), Hunter-Russell syndrome, and Minamata disease.
Symptoms typically include sensory impairment (vision, hearing, speech), disturbed sensation and a lack of coordination. The type and degree of symptoms exhibited depend upon the individual toxin, the dose, and the method and duration of exposure.
Adverse health effects associated with Cr(VI) exposure include occupational asthma, eye irritation and damage, perforated eardrums, respiratory irritation, kidney damage, liver damage, pulmonary congestion and edema, upper abdominal pain, nose irritation and damage, respiratory cancer, skin irritation, and erosion and discoloration of the teeth. Some workers can also develop an allergic skin reaction, called allergic contact dermatitis. This occurs from handling liquids or solids containing Cr(VI) such as portland cement. Allergic contact dermatitis is long-lasting and more severe with repeated skin exposure. Furthermore, contact with non-intact skin can lead to ulceration of the skin sometimes referred to as chrome ulcers. Chrome ulcers are crusted, painless lesions showing a pitted ulcer covered with fluid.
Workers today are still being exposed to lead that result in adverse health effects. Recent studies have provided evidence that lead can cause health effects at blood lead levels lower than those established by OSHA’s 1978 Lead standard.
Epidemiological and experimental studies indicate that chronic exposure resulting in blood lead levels (BLL) as low as 10 µg/dL in adults are associated with impaired kidney function, high blood pressure, nervous system and neurobehavioral effects, cognitive dysfunction later in life, and subtle cognitive effects attributed to prenatal exposure. Pregnant women need to be especially concerned with reducing BLL since this can have serious impact on the developing fetus.
Chronic exposures leading to BLLs above 20 µg/dL can cause subclinical effects on cognitive functions as well as adverse effects on sperm/semen quality and delayed conception. BLLs between 20 to 40 µg/dL are associated with effects such as cognitive aging as well as deficits in visuomotor dexterity, lower reaction times and attention deficit. At BBLs above 40 µg/dL, workers begin to experience symptoms such as headache, fatigue, sleep disturbance, joint pain, myalgia, anorexia, and constipation.
While much less common today, workers can be exposed to high lead levels resulting in BLL over 60 µg/dL. Health effects at these very high BLLs can range from acute effects such as convulsions, coma, and in some cases, death, to more chronic conditions such as anemia, peripheral neuropathy, interstitial kidney fibrosis, and severe abdominal cramping.
OSHA’s general industry and construction lead standards include a medical removal protection provision for workers whose blood lead levels reach or exceed 50 µg/dL (construction) or 60 µg/dL (general industry) Recently, medical management guidelines for adult lead exposure has been developed by a national expert panel coordinated by the Association of Occupational and Environmental Clinics (AOEC), in collaboration with the NIOSH Adult Blood Lead Epidemiology and Surveillance (ABLES) program. The panel recommends that maintaining BLLs below 20 µg/dL over a twenty-year period, or below 10 µg/dL over a forty-year period, would be sufficient to prevent chronic effects associated with cumulative exposures.
Based on limited evidence of human carcinogenic effects, workers may develop stomach cancer and lung cancer following inhalation exposure to lead, but more studies are needed to demonstrate the cancer risks compared to the levels and durations of lead exposure, and possibly confounding factors such as smoking, diet, and other carcinogens in the workplace. Experimental research indicates that rats and mice develop renal tumors following exposure to lead.
An obscure family of chemicals – important to the metalworking industry but virtually unknown to the public – is suddenly the subject of scrutiny from the U.S. Environmental Protection Agency.
The chemicals, called short-chain chlorinated paraffins, persist in the environment, accumulate in human breast milk, can kill small aquatic creatures and travel to remote regions of the globe.
Since their introduction in the 1930s, chlorinated paraffins have received little attention from U.S. authorities. But now the EPA, in an unprecedented move, has placed the compounds, known as SCCPs, on a short list of worrisome chemicals that the agency may regulate because of the risks they pose to wildlife and the environment.
“We find SCCPs worldwide,” said Tala Henry, acting deputy director of the EPA’s National Program Chemicals Division. “We’ve found them in animals in the Arctic and we have measured them in human tissues in several places around the globe.”
Despite evidence of widespread exposure, few scientists are actively studying the prevalence, toxicity and ecological impact of SCCPs. In contrast, other chemicals that persist in the environment – such as DDT and dioxins – have received far more attention from researchers.
“There is minimal awareness of these compounds,” said Gregg Tomy, an environmental chemist at the University of Manitoba in Canada. “It’s certainly not a chemical that’s on people’s radar screens.”
Chlorinated paraffins are a complex group of manmade compounds, primarily used as coolants and lubricants in metal forming and cutting. They also are used as plasticizers and flame retardants in rubber, paints, adhesives, sealants and plastics. The family of chemicals is organized into short, medium and long-chain paraffins, based on the length of their carbon backbones.
About 150 million pounds of chlorinated paraffins are used annually in the United States, according to the EPA. Ohio-based Dover Chemical Corp., the sole manufacturer of SCCPs in the United States, did not respond to requests for an interview.
“There is minimal awareness of these compounds. It’s certainly not a chemical that’s on people’s radar screens.” -Gregg Tomy, University of ManitobaAlthough Europe has restricted use of SCCPs, their manufacture is growing in China and possibly in India, raising concerns that worldwide exposure levels for people and wildlife might be increasing.
China’s production of the chemicals has increased 30-fold in fewer than 20 years.
“We are pretty worried at the moment,” said Jacob Boer, head of the department of chemistry and biology of the Institute for Environmental Studies at the Vrije Universiteit (VU University) in Amsterdam. “The increase of chlorinated paraffin production in China is exponential.”
In an unprecedented use of the 1976 Toxic Control Substances Act, the EPA in December placed short-chain chlorinated paraffins on a list of four chemicals that may pose unreasonable risks to health and the environment. In its action plan, the EPA announced its intentions to investigate and manage those risks, possibly restricting or banning future use of SCCPs in the United States.
It is the first time that the EPA has investigated the compounds, which are already regulated in Europe and under review in Canada.
Scientists have found the chemicals in the air, on land, in foods, in wastewater and in river and ocean sediments in North America, Asia, Europe and the Arctic, according to a report by a United Nations review committee for the Stockholm Convention, an international treaty that restricts toxic compounds.
“You find them pretty much wherever you go to look for them,” said Tomy, who found significant concentrations in sediments around the Great Lakes region.
SCCPs are accumulating in the fat tissues of freshwater fish such as trout and carp in North America and Europe, marine mammals including Beluga whales, ringed seals and walruses in the Canadian Arctic, land animals including rabbit, moose and reindeer in Sweden, and birds and seabird eggs in the United Kingdom.
Furthermore, certain SCCPs may biomagnify – meaning their concentration increases as they move through food chains, according to a 2008 field study on Lake Ontario trout.
Researchers have also measured SCCPs in human livers, kidneys, fat tissue and breast milk, according to the EPA action plan. Traces were found in 21 out of 25 samples of breast milk from women in London and Lancaster in a 2006 study in the United Kingdom. They also were measured in breast milk from Inuit women in Arctic Canada in a 1997 study by Tomy and colleagues.
“We are pretty worried at the moment. The increase of chlorinated paraffin production in China is exponential.” -Jacob Boer, Institute for Environmental Studies, Vrije Universiteit, AmsterdamHowever, since so few scientists are studying the toxicity of SCCPs and their impact on health and the environment, the consequences of the widespread exposure remain unclear.
SCCPs are highly toxic to small aquatic invertebrates and plants that fish and other animals feed on, so the chemicals may endanger aquatic ecosystems. But toxicity to humans and other mammals has been more difficult to determine.
“Whether these compounds are now challenging organisms, I can’t say for certain,” said Tomy. “But because they are so persistent, we can expect them to continue to accumulate. At some point there is going to be serious cause for concern.”
Laboratory tests show that SCCPs are highly toxic to Daphnia, tiny aquatic crustaceans known as water fleas that are important food sources in lakes, streams and other ecosystems, according to a 2000 European Union risk assessment.
To fish, the compounds are less acutely toxic, but chronic exposure damages them. Rainbow trout fed SCCPs in their food developed severe liver tumors, according to a study by Canadian researchers.
The concentrations that caused the fish tumors “were at levels that have been reported in invertebrates and fish from contaminated sites in the Great Lakes. However, the exposure concentrations were likely much greater in these experiments compared with the environment and require further study,” according to the 1999 study, whose senior author was Derek Muir, one of the world’s leading experts on persistent pollutants in fish and wildlife. Requests to interview Muir were denied by Environment Canada.
Other studies have found that SCCPs can cause slight egg shell thinning in mallard ducks and can damage the livers of otters.
Although there are no human studies on their effects, SCCPs can cause cancer in laboratory rats and mice, specifically damaging the liver, thyroid and kidney. Still, the EPA’s action plan and the UN report note that the mechanisms by which these cancers were induced in rodents are not relevant to human health.
For people who do not work in the metal industry, a primary route of exposure to the chemicals is food, according to the EPA action plan.
Researchers in 2002 measured SCCPs in cow’s milk and butter from Europe. They also have been found in many different foods in Japan, including grains, sugar, sweets and snacks, vegetables, fruit, fish, meats and milk. The concentrations were particularly high in shellfish, meat and fats, such as margarines and oils, according to the 2005 study in Japan.
How the chemicals got in the environment is not well understood. “We can confidently say there has been exposure, but exactly how they got there is a difficult question,” said Henry of the EPA.
Although there are no human studies on the effects of the chemicals, SCCPs can cause cancer in laboratory rats and mice, specifically damaging the liver, thyroid and kidney. Possible routes include accidental spills, runoff from disposal, and effluents of sewage treatment plants, states the EPA action plan. “SCCPs can be released during production, transportation, storage, and industrial use,” Tomy said.
The chemicals also might leach out of commercial plastic and rubber products in which they are used as flame retardants and plasticizers, he said. Once in the environment, SCCPs – which do not dissolve in water – bind to sediments and to tiny aquatic organisms, working their way up food chains.
According to Tomy, the inherent complexity of chlorinated paraffins makes it difficult for scientists to identify and analyze them.
“There are only a few labs in the world, and you can count them on one hand, that are actively working in this area because of the complexity,” Tomy said. “This makes PCBs [polychlorinated biphenyls] and PBDEs [polybrominated diphenyl ethers] seem like a walk in the park in terms of detection and quantification.”
“They are difficult to characterize,” Henry agreed. “There’s a difference in interpretation about what a short-chain chlorinated paraffin is.”
The result is that the EPA knows far less about SCCPs than other chemicals such as DDT that persist in the environment and accumulate in people and wildlife. “Compared with other persistent chemicals, there’s the least amount of toxicity and exposure data,” Henry said.
Nevertheless, several authorities already have regulated them. Their use and marketing are restricted in Europe. Both Health Canada and Environment Canada have deemed all chlorinated paraffins “toxic” under the Canadian Environmental Protection Act of 1999. Requests to interview Environment Canada scientists who have studied SCCPs were denied.
According to their new action plan, the EPA will consider using the Toxic Substances Control Act to “ban or restrict the manufacture, import, processing or distribution in commerce, export, and use of SCCPs” based on evidence about their environmental and health effects.
Although the EPA says it wants to move quickly to address the risks posed by SCCPs, the agency does not know when it will reach any regulatory decisions.
Under the federal toxics law, the EPA maintains an inventory of over 80,000 chemicals authorized for use in the United States. If a company wants to produce or use a chemical not found on that inventory, they must receive EPA approval by submitting a premanufacture notice that describes its environmental effects.
According to the EPA, some U.S. companies are using chlorinated paraffins that do not appear on the inventory. Tala said the EPA’s first step is to find out why.
Robert Fensterheim, executive director of the Chlorinated Paraffins Industry Association and President of RegNet Environmental Services, said he is not particularly concerned about the potential outcomes of the EPA’s action plan.
The EPA says it wants to move quickly to address the risks posed by SCCPs, but there is no timeframe for any regulatory decisions.“The effects on industry are not going to be broad scale,” Fensterheim said. “Given the limited amount that is produced and used, our assumption is that most people using the product already have responsible management in place. They won’t need to do anything they’re not already doing.”
Fensterheim disputes the EPA’s estimate that 150 million pounds are used annually in the United States. The demand, he said, is closer to 50 or 60 million pounds per year and decreasing.
“This is not a high volume chemical,” he said. “It’s been declining in its production value for quite some time.” The reason for the disagreement may be due to difficulty in defining exactly what a short-chain chlorinated paraffin is.
Manufacture and use of SCCPs have decreased in Canada, Europe and the United States but production is increasing at a rapid rate in China.
“If that production would have to be limited, it would be a major problem for the China metal industry,” said Boer of Amsterdam’s Vrije Universiteit. The increased production rate could also aggravate the ecological risks of the chemicals, he said.
The production of chlorinated paraffins in China soared from 20,000 tons in 1990 to over 600,000 tons in 2007, according to a 2009 presentation by Jiang Gui-bin of the State Key Laboratory of Environmental Chemistry and Ecotoxicology in Beijing, China. If this rate continues, production in China alone could soon surpass the entire historic, worldwide usage of PCBs, which remain a contaminant of global concern even though they were banned 32 years ago. Total worldwide PCB production was 1.3 million tons.
India also may be increasing its production of SCCPs, Boer said.
Although SCCPs are specifically defined as having a carbon backbone between 10 and 13 atoms long, there is still plenty of room for disagreement about which industrial products contain which chlorinated paraffins. The TSCA inventory, for example, does not distinguish between chlorinated paraffins of different carbon chain lengths.
Fensterheim said the companies believe the chemicals they use are already covered by the TSCA inventory, but the EPA disagrees.
Despite the inherent difficulties in studying the complex chemicals, Tomy said researchers need to keep monitoring their environmental levels and the toxicity to people and wildlife.
“I would like to believe in the coming years you are going to see more research,” he said.
This Public Health Statement is the summary chapter from the Toxicological Profile for chlorophenols. It is one in a series of Public Health Statements about hazardous substances and their health effects. A shorter version, the ToxFAQsâ„¢, is also available. This information is important because this substance may harm you. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present. For more information, call the ATSDR Information Center at 1-800-232-4636.
This public health statement tells you about chlorophenols and the effects of exposure.
The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in the nation. These sites make up the National Priorities List (NPL) and are the sites targeted for long-term federal cleanup activities. Chlorophenols has been found in at least 116 of the 1,467 current or former NPL sites. However, the total number of NPL sites evaluated for this substance is not known. As more sites are evaluated, the sites at which chlorophenols are found may increase. This information is important because exposure to this substance may harm you and because these sites may be sources of exposure.
When a substance is released from a large area, such as an industrial plant, or from a container, such as a drum or bottle, it enters the environment. This release does not always lead to exposure. You are exposed to a substance only when you come in contact with it. You may be exposed by breathing, eating, or drinking the substance or by skin contact.
If you are exposed to chlorophenols, many factors determine whether you'll be harmed. These factors include the dose (how much), the duration (how long), and how you come in contact with it. You must also consider the other chemicals you're exposed to and your age, sex, diet, family traits, lifestyle, and state of health.
1.1 What are chlorophenols?
Chlorophenols are a group of chemicals in which chlorines (between one and five) have been added to phenol. Phenol is an aromatic compound derived from benzene, the simplest aromatic hydrocarbon, by adding a hydroxy group to a carbon to replace a hydrogen. There are five basic types of chlorophenols: mono[one]chlorophenols, di[two]chlorophenols, tri[three]chlorophenols, tetra[four]chlorophenols, and penta[five]chlorophenols. In all, there are 19 different chlorophenols. Eight are discussed in this document: 2-chlorophenol, 4-chlorophenol, 2,4- dichlorophenol, 2,4,5-trichlorophenol, 2,4,6- trichlorophenol, 2,3,4,5-tetrachlorophenol, 2,3,4,6- tetrachlorophenol, and 2,3,5,6-tetrachlorophenol. Pentachlorophenol is discussed in another document.
Except for 2-chlorophenol, which is a liquid at room temperature, all of the chlorophenols are solids. The chlorophenols have a strong medicinal taste and odor; small amounts (at parts per billion [ppb] to parts per million [ppm] concentrations) can be tasted in water. Very small amounts of chlorophenols can also make fish taste bad. All the compounds discussed are or were produced commercially.
Chlorophenols with at least two chlorines either have been used directly as pesticides or converted into pesticides. Also, chlorophenols, especially 4- chlorophenol, have been used as antiseptics. In addition to being produced commercially, small amounts of some chlorophenols, especially the mono- and dichlorophenols, may be produced when waste water or drinking water is disinfected with chlorine, if certain contaminants are present in the raw water. They are also produced during the bleaching of wood pulp with chlorine when paper is being produced.
1.2 What happens to chlorophenols when they enter the environment?
Chlorophenols can enter the environment while they are being made or used as pesticides. Most of the chlorophenols released into the environment go into water, with very little entering the air. The compounds that are most likely to go into the air are the mono- and dichlorophenols because they are the most volatile (that is, have the greatest tendency to form vapors or gases). Once in the air, sunlight helps destroy these compounds and rain washes them out of the air. Chlorophenols stick to soil and to sediments at the bottom of lakes, rivers, or streams. However, low levels of chlorophenols in water, soil, or sediment are broken down by microorganisms and are removed from the environment within a few days or weeks.
Most people are exposed to very low levels of chlorophenols in drinking water that has been disinfected with chlorine (chlorinated drinking water). Chlorophenols have been measured in chlorinated drinking water at parts per trillion (ppt) concentrations (that is, the amount [weight] of chlorophenols per trillion parts [volume] of water). In lakes, rivers, and streams, chlorophenols were found in less than 1 percent of the water that was tested. Chlorophenols have been measured in city air at concentrations of less than a part per trillion (the amount of chlorophenols [volume] per trillion parts [volume] of air).
It has been estimated during the National Occupational Exposure Survey (NOES) from 1981ï¿½ 1983 that about 5,000 people in the United States are exposed to 4-chlorophenol, 2,4,5- trichlorophenol, or 2,4,6-trichlorophenol at work (NOES 1990). It has not been estimated how many people are exposed at work to the other chlorophenols. People who make chlorophenols or use them as pesticides are most likely to have high exposure to these chemicals. For example, mixtures of tetrachlorophenols are used at sawmills as wood preservatives. Skin contact while treating wood with the tetrachlorophenols is the most likely route of exposure. Another likely route of exposure is breathing air contaminated by mono- and dichlorophenols.
1.4 How can chlorophenols enter and leave my body?
When chlorophenols are eaten, almost all of the compounds quickly enter the body. Chlorophenols also rapidly enter the body through the skin. Little is known about how much of the chlorophenols enter the body if one breathes air containing them. The monochlorophenols do not stay inside the body very long. They are changed to less harmful products, and most leave through the urine within 24 hours. The other chlorophenols (dichlorophenol, trichlorophenols, tetrachlorophenols), which also leave through the urine as less harmful chemicals, can stay in the body for several days.
To protect the public from the harmful effects of toxic chemicals and to find ways to treat people who have been harmed, scientists use many tests.
One way to see if a chemical will hurt people is to learn how the chemical is absorbed, used, and released by the body; for some chemicals, animal testing may be necessary. Animal testing may also be used to identify health effects such as cancer or birth defects. Without laboratory animals, scientists would lose a basic method to get information needed to make wise decisions to protect public health. Scientists have the responsibility to treat research animals with care and compassion. Laws today protect the welfare of research animals, and scientists must comply with strict animal care guidelines.
One man who splashed pure 2,4-dichlorophenol on his arm and leg died shortly after the accident. Workers who made pesticides from chlorophenols and were exposed to chlorophenols as well as other chemicals through breathing and through the skin developed acne and mild injury to their livers. According to some studies, the risk of cancer was also slightly higher among workers who had made pesticides for a long time. These workers were exposed to very high levels of other chemicals as well as chlorophenols, so it is not certain whether the effects were caused by the chlorophenols or the other chemicals.
Animals that were given food or drinking water containing chlorophenols at high levels developed adverse or negative health effects. The major effects with exposure to high levels of chlorophenols were on the liver and the immune system. Also, the animals that ate or drank chlorophenols did not gain as much weight as the animals that ate food and drank water not containing chlorophenols.
Feeding rats and mice high doses of 2,4- dichlorophenol for a long time did not cause cancer. However, long-term treatment of rats and mice with high doses of 2,4,6-trichlorophenol in food caused leukemia in rats and liver cancer in mice, suggesting that 2,4,6-trichlorophenol may be a carcinogen. The Department of Health and Human Services has determined that 2,4,6-trichlorophenol may reasonably be anticipated to be a carcinogen. The International Agency for Research on Cancer (IARC) has determined that the chlorophenols as a group, are possibly carcinogenic to man. The Environmental Protection Agency (EPA) has determined that 2,4,6-trichlorophenol is a probable carcinogen.
Putting chlorophenols on the skin or eyes of animals causes severe injuries. Injury is greatest with exposure to the mono- and dichlorophenols. The signs of severe skin injury include redness, swelling, scabbing, and scar formation. The cornea was damaged when monochlorophenols were placed directly onto the eyes of rabbits.
This section discusses potential health effects from exposures during the period from conception to maturity at 18 years of age in humans. Potential effects on children resulting from exposures of the parents are also considered.
The most likely source from which children could be exposed to chlorophenols is water that has been disinfected with chlorine. Children could receive larger doses because they consume more fluids per bodyweight than adults. Children may also be exposed in areas where chlorophenols have been sprayed as pesticides or herbicides. Children playing outdoors in areas with contaminated soil could be at risk for exposure because they often put objects or hands in their mouths. Monochlorophenols are used as household antiseptics, and 2,4-DCP is used for mothproofing. More complex chlorophenols are used as biocides. Biocides are substances used to kill organisms.
We do not know whether chlorophenols cause birth defects in humans; chlorophenols have not been shown to cause birth defects in animals, even at high doses. High levels of chlorophenols given to pregnant female rats in the drinking water have tended to reduce the number of their newborn animals and to decrease the weights of the newborn. In one study animals exposed to chlorophenols showed delayed hardening of some bones. We do not know whether chlorophenols can cross the placenta or get into breast milk.
1.7 How can families reduce the risk of exposure to chlorophenols?
If your doctor finds that you have been exposed to significant amounts of chlorophenols, ask if children may also be exposed. When necessary your doctor may need to ask your state department of public health to investigate.
The chlorophenols presented in this profile exist in eight different forms, each one having different properties and uses. Therefore, different routes exist in which a family may be exposed to chlorophenols. Chlorophenols are primarily used as antiseptics, disinfectants, herbicides, pesticides, and wood preservatives. People are at greater risk of exposure if they live near industrial facilities that use or manufacture chlorophenols or waste sites that could be releasing it into the environment. Most released chlorophenols are found in surface water or have become adsorbed in soil near the release point. Children should be kept from coming in contact with water or dirt in an area that could be contaminated. You should prevent your children from eating dirt. Make sure they wash their hands frequently and before eating. Discourage your children from putting their hands in their mouths or other hand-to-mouth activity.
People who do not live near production or waste sites can still be exposed to chlorophenols through other routes. Chlorophenols can be present in drinking water when chlorine is used to disinfect it. The safe drinking water standard for 2-chlorophenol is 39 mg/L (monthly average). At low concentrations, chlorophenols give water an unpleasant, medicinal taste.
Chlorophenols and other related chemicals are often used as herbicides and pesticides. 2,4-D and 2,4,5- T, the latter of which has been banned, are herbicides often used on food crops that can break down to form 2,4-DCP. Children should be deterred from playing in areas where 2,4-D or other chlorophenol based herbicides or pesticides have been sprayed. Children are lower to the ground than adults and may be exposed because they often get dirt, grass, and other outdoor material on their skin and in their mouths. Also, your children may be exposed to chlorophenols if an unqualified person applies pesticides containing them around your home. In some cases, the improper use of pesticides banned for use in homes has turned homes into hazardous waste sites. Make sure that any person you hire is licensed and, if appropriate, certified to apply pesticides. Your state licenses each person who is qualified to apply pesticides according to EPA standards and further certifies each person who is qualified to apply "restricted use" pesticides. Ask to see the license and certification. Also ask for the brand name of the pesticide, a Material Safety Data Sheet (MSDS), the name of the product's active ingredient, and the EPA registration number. Ask whether EPA has designated the pesticide "for restricted use" and what the approved uses are. This information is important if you or your family react to the product.
If you buy over-the-counter pesticide products to apply yourself, be sure the products are in unopened pesticide containers that are labeled and contain an EPA registration number. Carefully follow the instructions on the label. If you plan to spray inside, make sure the pesticide is intended for indoor use.
If you feel sick after a pesticide has been used in your home, consult your doctor or local poison control center.
Chlorophenols may also be present in many household products. 2,4-DCP is commonly used for mothproofing. 4-CP is used as a disinfectant in homes, farms, hospitals, and as an antiseptic for root canal treatment. Monochlorophenols have been used as antiseptics, although they have largely been replaced by other chemicals. Pesticides and household chemicals should be stored out of reach of young children to prevent unintentional poisonings. Always store pesticides and household chemicals in their original labeled containers. Never store pesticides or household chemicals in containers children would find attractive to eat or drink from, such as old soda bottles.
1.8 Is there a medical test to determine whether I have been exposed to chlorophenols?
There is no medical test that is specific for chlorophenols to determine whether you have been exposed to these chemicals. Compounds that have been made by your body from chlorophenols can be measured in the urine. However, these compounds can also be found in the urine when you are exposed to other chemicals such as lindane (an insecticide) or to 2,4-dichlorophenoxyacetic acid (a chemical that kills weeds).
1.9 What recommendations has the federal government made to protect human health?
The federal government develops regulations and recommendations to protect public health. Regulations can be enforced by law. Federal agencies that develop regulations for toxic substances include the Environmental Protection Agency (EPA), the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA). Recommendations provide valuable guidelines to protect public health but cannot be enforced by law. Federal organizations that develop recommendations for toxic substances include the Agency for Toxic Substances and Disease Registry (ATSDR) and the National Institute for Occupational Safety and Health (NIOSH).
Regulations and recommendations can be expressed in not-to-exceed levels in air, water, soil, or food that are usually based on levels that affect animals, then they are adjusted to help protect people. Sometimes these not-to-exceed levels differ among federal organizations because of different exposure times (an 8-hour workday or a 24-hour day), the use of different animal studies, or other factors.
Recommendations and regulations are also periodically updated as more information becomes available. For the most current information, check with the federal agency or organization that provides it. Some regulations and recommendations for chlorophenols include the following:
The EPA recommends that drinking water concentrations of 2-chlorophenol should not be more than 0.04 part per million (ppm), and concentrations of 2,4-dichlorophenol should not be more than 0.02 ppm; these are levels that can be tasted. In order for chlorophenols to be lower than levels that can be tasted, the EPA recommends levels of 0.1 part per billion (ppb; the amount of chlorophenols per billion parts of water) for monochlorophenols, 0.3 ppb for 2,4- dichlorophenols, and 1 ppb for 2,4,5- trichlorophenol and 2,3,4,6-tetrachlorophenol.
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact: Agency for Toxic Substances and Disease Registry Division of Toxicology and Human Health Sciences 1600 Clifton Road NE, Mailstop F-57 Atlanta, GA 30329-4027 Phone: 1-800-CDC-INFO · 888-232-6348 (TTY) Email: Contact CDC-INFO
Hydrocarbons are organic compounds made primarily of carbon and hydrogen atoms. The addition of chlorine to the carbon-hydrogen chemical backbone increases the stability and decreases the flammability of the resulting compounds. Chlorinated hydrocarbon compounds are a diverse group of compounds, some of which are widely used in industrial and leisure activities. Common chlorinated hydrocarbons include carbon tetrachloride, methylene chloride, and trichloroethylene. These solvents have characteristic slightly pungent odors. They are used extensively in industry as cleaning, degreasing, and thinning agents because of their excellent solvent properties and low flammability relative to other effective solvents. They are also used in the manufacture of other chemicals including plastics and pesticides. Because of their high volatility and low boiling point, workplace exposures may be greater than anticipated. At high temperatures, these substances may decompose to yield highly toxic gases such as phosgene and hydrogen chloride. They are commonly encountered as mixtures with variable toxicity depending on the concentration of individual constituents.
Carbon tetrachloride is used infrequently due to its relative potency as a liver and kidney toxin. Methylene chloride (dichloromethane) is a common constituent of paint strippers, is very volatile, and can accumulate substantial amounts in enclosed spaces; it is metabolized to carbon monoxide and results in elevated carbon monoxide levels extending about 2.5 times longer than with carbon monoxide inhalation. In a small number of people, trichloroethylene will produce "degreaser's flush," a transient reddening of the face and neck, which occurs when the individual consumes even small quantities of alcohol. Sometimes this reaction may also produce a sensation of fullness in the chest and breathlessness.
As a class, the chlorinated hydrocarbons are potent central nervous system depressants or stimulants. They also cause greater liver and kidney damage compared to other organic solvents. Many have been shown to cause cancer in laboratory animals; due to widespread industrial use, the issue of carcinogenic risk to humans is one of the most controversial issues in regulatory toxicology. The chlorinated hydrocarbons have been implicated in causing sudden death at high exposure levels possibly related to the development of heart arrhythmias (ventricular fibrillation).
Exposure to chlorinated hydrocarbon compounds in the occupational setting is primarily through inhalation. Skin absorption is variable and usually insignificant, although dermal absorption following prolonged or extensive skin contact can cause systemic toxicity.
This Public Health Statement is the summary chapter from the Toxicological Profile for chlorobenzene. It is one in a series of Public Health Statements about hazardous substances and their health effects. A shorter version, the ToxFAQsâ„¢, is also available. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present. For more information, call the ATSDR Information Center at 1-888-422-8737.
This Statement was prepared to give you information about chlorobenzene and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) has identified 1,177 sites on its National Priorities List (NPL). Chlorobenzene has been found at 97 of these sites. However, we do not know how many of the 1,177 NPL sites have been evaluated for chlorobenzene. As EPA evaluates more sites, the number of sites at which chlorobenzene is found may change. The information is important for you because chlorobenzene may cause harmful health effects and because these sites are potential or actual sources of human exposure to chlorobenzene.
When a chemical is released from a large area, such as an industrial plant, or from a container, such as a drum or bottle, it enters the environment as a chemical emission. This emission, which is also called a release, does not always lead to exposure. You can be exposed to a chemical only when you come into contact with the chemical. You may be exposed to it in the environment by breathing, eating, or drinking substances containing the chemical or from skin contact with it.
If you are exposed to a hazardous substance such as chlorobenzene, several factors will determine whether harmful 'health effects will occur and what the type and severity of those health effects will be. These factors include the dose (how much), the duration (how long), the route or pathway by which you are exposed (breathing, eating, drinking, or skin contact), the other chemicals to which you are exposed, and your individual characteristics such as age, sex, nutritional status, family traits, life style, and state of health.
1.1 What is chlorobenzene?
Chlorobenzene is a colorless liquid with an almondlike odor. The compound does not occur widely in nature, but is manufactured for use as a solvent (a substance used to dissolve other substances) and is used in the production of other chemicals. Chlorobenzene persists in soil (several months), in air (3.5 days), and water (less than 1 day).
There is potential for humans to be exposed to chlorobenzene by breathing contaminated air, by drinking water or eating food contaminated with chlorobenzene, or by getting chlorobenzene contaminated soil on the skin. These exposures are most likely to occur in the workplace or in the vicinity of chemical waste sites.
Occupational exposure occurs primarily through breathing the chemical. Personnel engaged in the production and handling of chlorobenzene would be at greatest risk. Levels of chlorobenzene in the air at several industrial sites during normal operations were found to be below allowable federal standards. Exposure in humans could occur in persons living or working in the vicinity of hazardous waste sites if emissions to water, air, and soil are not adequately controlled.
Chlorobenzene has been found at 97 out of 1,177 NPL hazardous waste sites in the United States. Thus, federal and state surveys suggest that chlorobenzene is not a widespread environmental contaminant. The chemical has not been detected in surface water, although a few ground water systems have been found with chlorobenzene levels in the parts per billion (ppb) range. Background levels of less than 1 ppb were detected in air samples from urban and suburban areas. No information of the occurrence of chlorobenzene in food has been found.
1.3 How can chlorobenzene enter and leave my body?
Chlorobenzene enters your body when you breathe in air containing it, when you drink water or eat food containing it, or when it comes in contact with your skin. Human exposure to contaminated water could occur near hazardous waste sites where chlorobenzene is present. Significant exposure to chlorobenzene is not expected to occur by getting chlorobenzene contaminated soil on your skin. When chlorobenzene enters your body, most of it is expelled from your lungs in the air we breathe out and in urine.
Workers exposed to high levels of chlorobenzene complained of headaches, numbness, sleepiness, nausea, and vomiting. However, it is not known if chlorobenzene alone was responsible for these health effects since the workers may have also been exposed to other chemicals at the same time. Mild to severe depression of functions of parts of the nervous system is a common response to exposure to a wide variety of industrial solvents (a substance that dissolves other substances).
In animals, exposure to high concentrations of chlorobenzene affects the brain, liver, and kidneys. Unconsciousness, tremors and restlessness have been observed. The chemical can cause severe injury to the liver and kidneys. Data indicate that chlorobenzene does not affect reproduction or cause birth defects. Studies in animals have shown that chlorobenzene can produce liver nodules, providing some but not clear evidence of cancer risk.
1.5 What levels of exposure have resulted in harmful effects?
It is not known what levels of exposure to chlorobenzene result in harmful health effects in people. In animals, exposure to 75 parts per million (ppm) chlorobenzene in air or approximately 2,000ï¿½ 5,000 ppm in food resulted in liver and kidney damage.
1.6 Is there a medical test to determine whether I have been exposed to chlorobenzene?
Exposure to chlorobenzene can be determined by measuring the chemical or its metabolite in urine, exhaled air, blood, and body fat. Tests are not routinely available at the doctor's office. Specific tests are available that can determine if exposure is currently occurring or has occurred very recently, but not whether exposure occurred in the past. Further, levels in the various media stated above do not predict adverse health effects.
1.7 What recommendations has the federal government made to protect human health?
The EPA has set a Maximum Contaminant Level (MCL) of 0.1 parts per million (0.1 ppm) for chlorobenzene in drinking water. Concentrations in drinking water for short-term exposures (up to 10 days) should not exceed 2 ppm. The EPA recommends that levels of chlorinated benzenes (a group of chemicals that includes chlorobenzene) in lakes and streams should be limited to 0.488 ppm to prevent possible health effects from drinking water or eating fish contaminated with this group of chemicals. Any release to the environment greater than 100 pounds of chlorobenzene must be reported to the EPA.
The Occupational Safety and Health Administration (OSHA) has set a workplace air concentration limit of 75 ppm over an 8-hour workday, 40-hour workweek.
The federal recommendations have been updated as of July 1999.