February 16, 2023

Vinyl Chloride Among Four Tox Profiles Released for Public Comment

New toxicological profiles for the substances cobalt, hexachlorocyclohexane, 1,1,1-trichloroethane, and vinyl chloride are available from the Agency for Toxic Substances and Disease Registry (ATSDR). Tox profiles are peer-reviewed evaluations of toxicological information on hazardous substances. Each tox profile includes discussions about the health effects of a substance, its relevance to public health, its potential for human exposure, regulations and guidelines related to the substance, and other information.

The tox profile for vinyl chloride was last updated in 2006. In the United States, the use of vinyl chloride in consumer products was banned in 1974, but the substance is still used by the plastics industry to produce polyvinyl chloride, or PVC. Workers and people who live near plastic manufacturing facilities or hazardous waste sites may be exposed to vinyl chloride through inhalation. Workers may also be exposed through skin absorption. Among the many potential health effects of vinyl chloride exposure are liver damage and cancer. Access the tox profile for vinyl chloride from the ATSDR website.

On Feb. 3, a train carrying vinyl chloride derailed near East Palestine, Ohio, a town of about 4,700 residents. Three days later, authorities conducted a controlled release and burn in an effort to prevent an explosion. Because one of the byproducts of burning vinyl chloride is phosgene, a highly toxic gas used as a chemical weapon during World War I, the governors of Ohio and Pennsylvania ordered an immediate evacuation of residents of a 1-by-2 mile area straddling the border between the states. The orders were lifted Feb. 8. However, amid reports of dead fish and other animals in the area, Ohio officials continue to recommend that some East Palestine residents drink bottled water while municipal supplies and wells are tested, according to The New York Times.

Some compounds of cobalt, a naturally occurring metal, are used in rechargeable batteries and as alloys in gas turbine aircraft engines. The general population is exposed to cobalt mostly through inhalation and ingestion. Occupational exposures can occur to workers in tool production, grinding, and other hard-metal industries such as coal mining, metal mining, smelting, and refining. Studies of occupational exposure to cobalt have found health effects including decreased pulmonary function, asthma, and interstitial lung disease. Workers at nuclear facilities, irradiation facilities, or nuclear waste storage sites may also be exposed to radioactive cobalt. Access the tox profile for cobalt from the ATSDR website.

Hexachlorocyclohexane, or HCH, is a mixture of eight isomers, one of which (lindane) is an insecticide that was used broadly in agriculture in the U.S. beginning in the 1940s. EPA began limiting the use of lindane for agricultural purposes in the 1970s and eventually, in 2006, canceled the agency’s registrations for products containing lindane. Food and Drug Administration-regulated prescription products containing 1 percent lindane are available as treatments for lice and scabies. Use of these products typically results in the highest exposures to lindane. Workers in facilities that use or process lindane and people who live near sites contaminated with HCH may also have increased exposure. Access the tox profile for HCH from the ATSDR website.

1,1,1-Trichloroethane previously had many industrial and residential uses, including as a solvent and as a component of spot cleaners, glues, and aerosol sprays. In 2002, EPA banned its production for domestic use in the U.S. due to the substance’s effects on the ozone layer. A variety of neurological and hepatic effects can result from exposure to large amounts of 1,1,1-trichloroethane, but the current exposure risk from consumer products and workplaces in the U.S. is understood to be minimal, according to ATSDR. Access the tox profile for 1,1,1-trichloroethane from the ATSDR website.

The four new tox profiles are in draft form. Comments on these profiles may be submitted through May 10 via Regulations.gov. Other tox profiles are available from the ATSDR website.

This article was updated on Feb. 17, 2023, to correct the date of the train derailment in East Palestine, Ohio. The train derailed on Feb. 3, and the controlled burn of the train's contents began on Feb. 6.