NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Methanol

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for methanol to cause adverse effects on reproduction and development in humans. Methanol was selected for evaluation because it is a high production volume chemical with high potential for occupational, consumer, and environmental exposure. Methanol is used in chemical syntheses and as an industrial solvent. It is found in a variety of consumer products such as paints, antifreeze, cleaning solutions, and adhesives and is a by-product of sewage treatment, fermentation, and paper production. Methanol is used in racecar fuels, and there is the potential for the expanded use of methanol as a vehicle fuel or fuel additive. Methanol occurs naturally in a variety of fresh fruits and vegetables, alcoholic beverages, and cigarette smoke. The results of this evaluation on methanol are published in an NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Methanol, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to methanol on human development and reproduction. First, there is concern for adverse developmental effects in fetuses if pregnant women are exposed to levels of methanol that result in high blood concentrations, such as with acute methanol poisoning. Although there is insufficient evidence to determine if a human fetus is more or less sensitive than rodents to the adverse effect of methanol, humans suffering acute methanol poisoning may have blood levels similar to those resulting in developmental toxicity in rodents. Second, for exposures that result in low blood methanol concentrations (below approx. 10 mg/L blood), there is minimal concern for adverse developmental effects , and negligible concern for adverse male reproductive effects. There is insufficient evidence to assess the effects of methanol on female reproduction. Data available to the expert panel were not sufficient to rule out the possibility of male reproductive effects at toxic exposure levels. The panel judged that blood levels >/=10 mg/L are not expected to result from normal dietary or occupational exposures. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site (http://cerhr.niehs.nih.gov) and in printed text or CD-ROM from the CERHR (National Institute of Environmental Health Sciences, P.O. Box 12233, MD EC-32, Research Triangle Park, NC; fax: 919-316-4511).