Three Draft Tox Profiles Available from ATSDR

The Agency for Toxic Substances and Disease Registry has published draft toxicological profiles for acrolein; n-hexane; and naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene. The agency is accepting comments on the draft tox profiles through Aug. 1.

Acrolein is primarily used in the manufacture of acrylic and other organic chemicals. It is also used as a biocide in agricultural and industrial water systems, the manufacture of the animal feed supplement methionine, and in chemical weapons. The general population is exposed to acrolein primarily through smoking, cooking with oils and fats, and building materials. Inhalation of acrolein can result in nasal and throat irritation and decreased breathing rate, while oral exposure can lead to gastrointestinal irritation. In vapor or liquid form, acrolein can also cause eye irritation. While the International Agency for Research on Cancer classifies acrolein as “probably carcinogenic to humans,” ATSDR did not identify adequate studies for evaluating its carcinogenic potential.

n-Hexane, a hydrocarbon refined from crude oil, is used as a volatile nonpolar solvent, in glues and adhesives, and in laboratories as an extractant. Solvents that contain n-hexane are used as cleaning agents in the printing, textile, furniture, and shoemaking industries. Its presence in gasoline suggests that much of the U.S. population is potential exposed to low levels of n-hexane from vehicle emissions. Exposures to concentrations of 500 ppm for two months are associated with human neurotoxicity. Severe occupational exposures have resulted in paralysis. Little information exists on the carcinogenic potential of n-hexane, which has not been assessed by IARC.

Naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene occur naturally in fossil fuels and are produced when organic materials are burned. Occupational exposure to naphthalene was associated with irritation and inflammation in the nose, and exposures to naphthalene vapors from mothballs have been associated with headaches, confusion, lethargy, and vertigo. The U.S. National Toxicology Program classifies naphthalene as “reasonably anticipated to be a human carcinogen,” while IARC has determined that it is “possibly carcinogenic to humans.”

Comments may be submitted through the docket on Regulations.gov.

Tox profiles are peer-reviewed evaluations of toxicological information on hazardous substances. A full list of toxic substances with published profiles is available on ATSDR website.