WASHINGTON (December 19, 2017) – A research report released by the National Toxicology Program (NTP) details a National Institute of Environmental Health Sciences (NIEHS) study that found formaldehyde inhalation did not cause leukemia in genetically predisposed strains of mice. Due to the lack of transparency in the process, there is continuing concern over the Environmental Protection Agency’s (EPA) failure to incorporate all the available science in the 2010 draft Integrated Risk Information System (IRIS) assessment of formaldehyde and any revisions that have been underway since that time.
The hypothesis of the study was that mice bred with specific genetic traits making them extra sensitive to mutagenic carcinogens would have an increased risk of developing nasal carcinogenicity, leukemia or lymphohematopoietic cancer when exposed to formaldehyde. However, the study found that inhalation of a maximum tolerated dose of formaldehyde, a dose that was more than 100 times the occupational exposure limit, did not cause nasal tumors, an increased prevalence of leukemia or lymphohematopoietic cancer, or any other type of cancer.
These findings are part of a growing body of epidemiological, toxicological, and mechanistic data that supports the conclusion that formaldehyde exposure does not cause leukemia and calls into question EPA’s previously proposed cancer risk value. All ongoing and future assessments of formaldehyde should incorporate this important information into the full body of scientific evidence.
NTP’s report, Absence of Formaldehyde-Induced Neoplasia in Trp53 Haploinsufficient Mice Exposed by Inhalation, details the research. The federally-funded study results have not yet been published in a peer-reviewed journal.