Chemical Families

Chemical Families

Chemicals can be grouped according to different properties, such as function, persistence, toxicity, structure, etc.

Amphibole-group minerals

Antimony compounds

Arsenic compounds

Arsenic powder has been the poisoner's choice since Nero's day. Yet chemists through the ages have formulated less toxic arsenic compounds into artist's colors and dyes, glass, alloys of lead, copper and brass, pesticides, cosmetics, tonics and even medicines.

But no arsenic concoction is without risk. Some scholars theorize that Paris green, a once-popular arsenic-based wallpaper pigment, caused Napoleon's mysterious demise in 1821. In the late 19th century, Italian scientist Bartolomeo Gosio linked the deaths of more than 1,000 children to arsenic vapors from moldy green wallpaper. In 1887, British physician Jonathan Hutchinson reported that arsenic-based medications for syphilis, asthma and psoriasis caused skin cancer.

In 1980, the National Toxicology Program's first Report on Carcinogens listed inorganic arsenic compounds as known human carcinogens. Inorganic arsenic-based pesticides were banned in the years that followed. By 1985, the U.S. had stopped producing arsenic.

Still, America remained the world's leading arsenic consumer, with imports soaring from 14,200 metric tons in 1985 to 25,000 tons by 2001, according to the U.S. Geological Survey.

Some 86 to 90 percent of imports were being made into chromated copper arsenate (CCA), a wood preservative for "pressure-treated" decking, landscaping, walkways, picnic tables and playground equipment. The rest went into semiconductors, specialized metal, a few remaining pesticides and treatments for acute leukemia and other cancers.

In 2001, the Environmental Working Group launched its Poisoned Playgrounds initiative to build support for a ban on arsenic in all consumer products. In November 2001, an EWG analysis entitled The Poisonwood Rivals found that pressure treated wood sold by The Home Depot and Lowe's Home Improvement Warehouse leached as much as1,020 micrograms of pure arsenic -- 100 times the U.S. Environmental Protection Agency's 10 microgram "allowable daily exposure level" for drinking water -- onto a moistened wipe the size of a four-year-old's hand.

On February 12, 2002, under pressure by consumers, members of congress and the EPA, the wood industry agreed to stop using arsenic-based wood preservatives as of December 2003. By 2006, US consumption of arsenic had dropped more than 300 percent. That year, the EPA attempted to ban all arsenic-based pesticides. The proposed regulation is still tied up in regulatory wrangles. Consequently, organic arsenic herbicides are still in use on cotton and turf, including golf courses, lawns, school yards, athletic fields, and rights-of-way.

Many older outdoor wooden structures still contain arsenic. To find out if your wooden deck, picnic table, or playset is leaching the chemical, click here for a test kit order form.

Bisphenol a (BPA), a synthetic estrogen used to harden polycarbonate plastics and epoxy resin, is the focus of a growing number of research studies and legislative actions, reflecting mounting scientific evidence that it causes serious and sometimes irreversible damage to health, even at the low doses to which people are routinely exposed. In laboratory tests, trace BPA exposure been shown to disrupt the endocrine system and trigger a wide variety of disorders, including chromosomal and reproductive system abnormalities, impaired brain and neurological functions, cancer, cardiovascular system damage, adult-onset diabetes, early puberty, obesity and resistance to chemotherapy.

BPA is one of the highest production chemicals in international commerce. An estimated 6 billion pounds of BPA are produced globally annually, generating about $6 billion in sales. It is fabricated into thousands of products made of hard, clear polycarbonate plastics and tough epoxy resins, including safety equipment, eyeglasses, computer and cell phone casings, water and beverage bottles and epoxy paint and coatings. But BPA-based plastics break down readily, particularly when heated, washed with strong detergent or stored with acidic foods like tomatoes.

In March 2007, Environmental Working Group published a ground-breaking study documenting that online guide to baby-safe bottles and formula.

EWG GUIDES

Botanical essential oils

Brominated dioxins & furans

Dioxins and furans are created when plastic or wastes are incinerated. They are dispersed in the environment and accumulate in fish and other fatty foods. Dioxins and furans are highly toxic and disrupt brain development and hormone systems, particularly in the developing fetus.

Brominated Fire Retardants

Cadmium compounds

Calcium compounds

Chlorinated dioxins & furans

Haloacetic acids are another class of common byproducts of water disinfection, including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. The human health effects have not been well documented, howeversome epidemiological studies suggest that HAA exposure during the second and third trimesters of pregnancy may be linked to birth defects in newborns. Exposure can be dramatically reduced with a filtration system.

Since ancient times, lead has been fashioned into pipes, paints, eating utensils, cosmetics, spermicide and, more recently, ammunition, batteries, ceramics, solder and fuel additives. The Romans knew that high doses of the heavy, malleable blue-gray metal caused madness and death and relegated lead mining to far provinces. Yet they continued to use lead cups, plates and armor, unaware of the debilitating effects of chronic exposure to small amounts of lead.

The insidious symptoms of slow lead poisoning -- impaired intellect, memory loss, mood swings, infertility, nerve, joint and muscle disorders, cardiovascular, skeletal, kidney and renal problems and possibly cancer -- were not fully recognized until the late 20th century. In 1973, the U.S. Environmental Protection Agency began phasing out leaded gasoline, a process that was to drag on until 1996. Lead was banned in household paint in 1978. As a result, according to the National Institute of Environmental Health Sciences, lead levels in the blood of American children have dropped by 86 percent since the late 1970s.

Still, research by the Environmental Working Group has continued to uncover lead hazards, especially to the most vulnerable members of society. In 2000, an EWG analysis found that about 212,000 one-to-five-year-olds in California had harmful blood lead levels between 1992 and1998, but the state had identified only 14, 900 of those children. A 2004 EWG study in Ohio found that 19,000 under age six had unsafe levels of lead in their blood. Less than one-third of them had been reported to state health authorities, primarily because they had not been tested.

EWG's Human Toxome Project, initiated in late 2006 in collaboration with Commonweal, a California health and environmental research group and aimed at mapping toxins in various populations, found lead in all 56 individuals tested by EWG/Commonweal and 13,641 of the 14,333 people tested in CDC biomonitoring studies. Scientific testing and analysis under the Toxome Project is continuing, with a goal of mapping human body burdens globally.

Meanwhile, EWG is pressing for passage of the federal Kid-Safe Chemicals Act, introduced in 2008 in an effort to strengthen the Toxic Substances Control Act of 1976 and protect Americans, especially children, from industrial chemicals like lead that contaminate air, water, food and living spaces.

Mercury, a metallic element, is a silvery liquid that vaporizes when heated into a highly toxic, odorless gas. Mercury compounds once common in pesticides and industrial processes are also toxic, causing damage to the brain and nervous system, immune system, enzyme system and genetic system.

The organic compound methylmercury, an environmental contaminant that accumulates in some fish and fish-eating wildlife, is particularly devastating to developing fetuses. The international movement to curb industrial pollution was galvanized by photojournalist W. Eugene Smith’s iconic 1971 photograph of a Japanese mother bathing her blind, deformed daughter, a casualty of a chemical company’s mercury dumping into Minamata Bay. The Minamata catastrophe devastated thousands of lives and forced the U.S., Japan and other nations to confront the mercury pollution problem. U.S. regulators barred the last of the mercury-laden pesticides in 1995. Other industrial uses remain: between 2004 and 2007, according to the U.S. Geological Survey, American industry imported more than 1 million tons of mercury.

In 1997 the Environmental Working Group’s analysis, Contamination of America's Food, concluded that fish from more than 1,660 U.S. waterways were so contaminated with mercury that they should be eaten sparingly or not at all. Soon after, the EPA confirmed that more than 1.6 million women and children could face serious health risks from mercury-contaminated food. But it took two more years for the EPA and the U.S. Food and Drug Administration to issue warnings to women to limit fish consumption during pregnancy to 12 ounces a week. The FDA failed to caution against excessive consumption of tuna. EWG challenged the agency’s advice as vague and misleading -- and unearthed internal FDA transcripts in which agency officials opined that canned tuna contained enough mercury to harm the developing brain of a baby in the womb.

In January 2004, after the FDA had repeatedly failed to give consumers clear, science-based data, EWG released an interactive Tuna Calculator to help people figure their own safe doses of tuna, based on weight. It advised women of child-bearing age and children under 5 not eat albacore tuna at all.

The mercury threat persists. In July 2005, EWG reported finding mercury in the cord blood of 10 newborn babies. These findings were echoed by EWG's Human Toxome Project, initiated in late 2006, that found methylmercury in 72 of the 73 people tested.

Metals

Miscellaneous pesticides

Molybdenum compounds

Nano-scale Materials

Nanoscale materials are characterized by very small particles whose surface area and shape imparts unique and useful properties. While the health impacts and absorption of these particles by humans is poorly understood, there are a number of studies demonstrating different toxicities compared to larger particles. Consumers are exposed to them through thousands of products including a variety of cosmetics and sunscreens.

Natural products

Nickel compounds

Nitrate compounds

Nitrates are nitrogen-oxygen compounds released into the environment from the widespread use of nitrogen-based fertilizers, human sewage and animal manure. High nitrate levels in well water can cause the sometimes-fatal “blue baby” syndrome in infants, impairing the blood’s capacity to carry oxygen. Over years, adults consuming excess nitrates can suffer kidney and spleen damage. According to the Agency for Toxic Substances and Disease Registry, nitrates can react with the body’s amino acids to form nitrosamines, linked to cancer in test animal studies. The U.S. Environmental Protection Agency sets a limit of 10 parts per million for nitrates in drinking water.

In estuaries, nitrates cause algae blooms that quickly deplete the water of oxygen and create “dead zones,” killing bottom-dwelling organisms such as shellfish and crabs and fish that cannot escape the area. In January 2008, the U.S. Geological Survey (USGS) reported that two-thirds of the nitrogen causing the 8,000-square-mile Dead Zone in the Gulf of Mexico came from fertilizer runoff from farms along the Mississippi River. Application of nitrogen-based fertilizers also leads to emissions of nitrous oxide, a greenhouse gas that has 300 times the global warming potential of carbon dioxide.

The Environmental Working Group has been in the forefront of the effort to reform agriculture policies, advance conservation and curb the pollution that is killing the Gulf. In a 2006 report, Dead in the Water, EWG concluded that farms encompassing just 15% of the land in the Mississippi River Basin are responsible for 80% of the spring surge of nitrates feeding the Dead Zone; in the areas where nitrate runoff is worst, the study found, the U.S is spending just $1 on water quality for every $500 in crop subsidies. In a 2007 report, Trouble Downstream, EWG recommended that farmers who benefit from taxpayer support be required to show tangible progress in reducing soil erosion and nitrate runoff.

In a 2008 analysis, The Unintended Environmental Impacts of the Renewable Fuel Standard, EWG concluded that increased corn cultivation to make biofuel would accelerate soil erosion, intensify use of chemical fertilizers and pesticides and aggravate nitrate runoff into the fragile Gulf. Also, EWG said, expanding corn farming would heighten demand for water for irrigation, stressing underground water sources, and degrade shrinking wildlife habitat.

Nitro- and polycylic- musks

Organochlorine Pesticides (OCs)

Organophosphate Pesticides (OPs)

Oxides

Parabens

Parabens are widely used synthetic preservatives found in the most of the nearly 25,000 cosmetics and personal care products in Skin Deep. Parabens can disrupt the hormone (endocrine) system, and were found in the breast cancer tumors of 19 of 20 women studied. The Centers for Disease Control (CDC) tested urine from 100 adults and found parabens in nearly all.

Perchlorate

Ammonium perchlorate is the oxidant in solid rocket fuel. Ignited with aluminum powder, it burns at up to 6,000 degrees Fahrenheit, hurling the space shuttle out of the atmosphere and propelling ballistic missiles across continents. A combination of nitrogen, hydrogen, chlorine and oxygen, ammonium perchlorate is an essential component of military explosives, bottle rockets, fireworks, highway flares, automobile airbags and old-fashioned black powder. Ammonium perchlorate and other perchlorate compounds are also widespread contaminants of drinking water and some foods such as milk and vegetables. In significant amounts, perchlorate disrupts the thyroid’s functioning and may cause thyroid cancer. The U.S. Environmental Protection Agency says drinking water containing less than 24.5 parts per billion of perchlorate poses no hazard to humans, but the Environmental Working Group’s research supports lowering the standard to 1 part per billion. In a 2001 investigation called Rocket Science: Perchlorate and the Toxic Legacy of the Cold War, EWG found that perchlorates had been detected the sources in drinking water for more than 7 million Californians. A 2003 EWG analysis of government data, Rocket Fuel in Drinking Water, determined that perchlorate had been found in drinking water, groundwater or soil in at least 43 states. EWG commissioned independent laboratory tests of lettuce grown in the fall and winter in Southern California or Arizona. Some 18 percent of the lettuce samples contained perchlorates; someone who ate an average serving of these suspect salads would consume 4 times more perchlorates than the level considered safe by the U.S. Environmental Protection Agency. In 2004, EWG-commissioned lab tests of milk sold in Los Angeles and Orange County, CA, supermarkets found that 31 of 32 samples contained perchlorates, some at unsafe levels for infants and children. In October 2007, EWG set up a groundbreaking, interactive National Tap Water Quality database of water contaminants found in 42 states over 2 ½ years. With the database’s launch, for the first time, the public has been able to access information about specific local water supplies across the U.S. In January 2008, an EWG analysis of data from the U.S. Food and Drug Administration (FDA) found that 75 percent of nearly 300 commonly consumed foods and beverages were contaminated with perchlorate. The study found that the average two-year-old would be exposed to more than half of the EPA's safe dose of perchlorate from food; the toddler could reach or exceed the daily limit by consuming more of the chemical in drinking water.

Perfluorochemicals (PFCs)

Polyfluorinated chemicals are widely used as water, stain and grease repellants for food wrap, carpet, furniture, and clothing that have been detected in adults, newborns, and wildlife all around the globe. They persist in the body for decades, acting through a broad range of toxic mechanisms to present potential harm to a wide range of organs. EWG's work has resulted in an international phaseout effort and court victories against major manufacturers.

Petroleum distillates and process streams

Pharmaceuticals

Phenols

Phthalates

Phthalates, called “plasticizers,” are a group of industrial chemicals used to make plastics like polyvinyl chloride (PVC) more flexible or resilient and also as solvents. Phthalates are nearly ubiquitous in modern society, found in, among other things, toys, food packaging, hoses, raincoats, shower curtains, vinyl flooring, wall coverings, lubricants, adhesives, detergents, nail polish, hair spray and shampoo.

Phthalates have been found to disrupt the endocrine system. Several phthalate compounds have caused reduced sperm counts, testicular atrophy and structural abnormalities in the reproductive systems of male test animals, and some studies also link phthalates to liver cancer, according to the U.S. Center for Disease Control’s 2005 National Report on Human Exposure to Environmental Chemicals. Though the CDC contends the health hazards of phthalates to humans have not been definitively established, for some years, the U.S. Environmental Protection Agency has regulated phthalates as water and air pollutants.

The Environmental Working Group has focused on phthalates since 1998, when EWG reported that dibutyl phthalate found in 37 nail polishes was also present in the bodies of every single American tested. A 2000 EWG analysis of CDC data, called Beauty Secrets, found that dibutyl phthalate was present in the bodies of every single person tested for industrial pollutants.

In 2003, EWG published its seminal Body Burden study, finding 210 industrial and consumer product chemical, among them, a half-dozen phthalates, in nine adult Americans who had agreed to submit their blood and urine to laboratory analysis. In 2007 EWG published a Parents Buying Guide, a safety guide to help parents find children’s personal care products that are free of phthalates and other potentially dangerous chemicals.

In July 2008, as a result of pressure from EWG and other health groups, the U.S. Congress passed legislation banning six phthalates from children’s toys and cosmetics. Legislators in Washington, Vermont and California have restricted phthalate use in children’s goods, and several major retailers, including Wal-Mart, Toys-R-Us, Lego, Evenflo and Gerber say they will phase out phthalate-laden toys.

EWG advocates a cumulative assessment of the human health risks, especially to infants, of phthalates. As well, EWG is working for passage of a new federal Kid-Safe Chemicals Act to reform the nation’s toxic chemical law to assure that chemicals are safe for babies, children and other vulnerable groups before they are allowed on the market.

Polyaromatic hydrocarbons (PAHs)

Polybrominated diphenyl ethers (PBDEs)

PBDEs are chemicals used as fire retardants in foam furniture and the plastic of TVs and computer monitors. They accumulate in people and wildlife and disrupt brain development and hormone systems. 2 forms of PBDEs have been pulled from the US market after EWG and others revealed high levels in the blood, milk and body tissues of Americans, but a 3rd type is still used in electronics.

Polychlorinated biphenyls (PCBs)

Polychlorinated biphenyls (PCBs), heat-resistant and non-conductive liquids and resins, came into use in the 1930s as coolants and lubricants for various electrical equipment, including transformers, capacitors, vacuum pumps turbines, surface coatings, plasticizers, pesticide extenders and copy paper. By 1974, according to the U.S. government’s Report on Carcinogens, which says PCBs are “reasonably anticipated to be a human carcinogen, Monsanto Chemical Company manufactured 99 percent of the PCBs used by U.S. industry, producing 40 million pounds a year.

Studies in 1970s linked PCBs to cancer and other health problems. U.S. companies stopped manufacturing PCBs in 1977, and the Environmental Protection Agency banned most uses in 1979. But PCBs are extraordinarily persistent in the environment. Improper disposal of old PCB-laden equipment and industrial items continue to leach the chemical into soil and water, where they persist for decades and contaminate the marine food chain. According to EPA, from 1987 to 1993, PCB releases to land and water totaled over 74,000 pounds, much of them in California.

In 2003, the Environmental Working Group obtained documents showing that EPA’s cleanup agreement with Monsanto for PCB contamination at an old plant site in Anniston, Ala. had changed significantly in Monsanto’s favor shortly after President Bush’s first EPA administrator, Christine Todd Whitman, visited the site. EWG’s June 2003 report -- How did Monsanto avoid a pollution crackdown in Alabama? – led veteran Superfund attorney Janet MacGillivray to disclose that a senior Bush Department of Justice (DOJ) official tried to pressure her into not testifying in a federal court reviewing the pollution cleanup agreement.

Ultimately, Solutia, Monsanto’s successor company and EPA, reached a settlement calling for $600 million to be paid for a site cleanup and to 21,000 Anniston residents exposed to PCBs for decades. The cleanup is still going on.

In July 2003, EWG made a major national impact with the first-ever report showing that 7 of 10 farmed salmon were contaminated with PCBs at levels that raise concern about cancer risks. EWG’s analysis found that 800,000 American adults ingested enough farmed salmon to exceed lifetime cancer risk levels by a factor of 100.

Polychlorinated naphthalenes (PCNs)

Polymer derivatives

Potassium compounds

Radioactive compounds

Radioactive particles

Selenium compounds

Short halogenated compounds

Siloxanes and silicones

Trihalomethanes (THMs)

THMs, the most common byproducts formed when water is disinfected, are comprised of four compounds: chloroform, bromodichloromethane, dibromochloromethane and bromoform. Numerous studies have shown that although drinking water is a major exposure route for THMs, showering and bathing are important routes through inhalation and dermal absorption. High concentrations of THMs have been associated with varying degrees of birth defects. To decrease exposure to THMs, consumers should consider buying water filtration systems.

Unidentified or misc. family

Uranium compounds

UV filters

Vanadium compounds

Volatile and semivolatile organic compounds (VOCs and SVOCs)

Zinc compounds

Zirconium compounds