The original paper – published in January 2010 by Luoping Zhang and 33 co-authors in Cancer Epidemiology, Biomarkers & Prevention – compared the presence of reported chromosomal abnormalities in a small group of Chinese workers occupationally exposed to formaldehyde to the presence of the abnormalities in unexposed workers. The researchers suggested that the observed differences might indicate a mechanism linking formaldehyde exposure to leukemia.

Several health assessment organizations have used the 2010 Zhang studys conclusions as the basis to conclude formaldehyde causes leukemia, including the International Agency for Research on Cancer, and the U.S. Environmental Protection Agency, which relied on the study in its 2010 draft assessment of formaldehyde health risks under its Integrated Risk Information System. That draft assessment was criticized by a 2011 National Academy of Sciences peer review report.

Formaldehyde-condensing biocides have been used for decades to control microbial contamination in metalworking fluids because they are economical and effective against a wide variety of microbes. The concern over formaldehyde-condensates in metalworking fluids has been that they have potential to release formaldehyde – classified as a human carcinogen – during metalworking processes.

Kenneth Mundt, the lead author of the reanalysis and health science global practice network leader and director of applied epidemiology for Ramboll Environ, has led several studies that analyze the health risks from formaldehyde exposure. The weight of scientific evidence does not support a causal association between formaldehyde and leukemia, Mundt said in an American Chemistry Council news release about the new study.

Mundt and his co-authors in their paper analyzed raw data from the Zhang study, including previously unavailable data on individual workers exposure to formaldehyde. That data was recently released by the National Cancer Institute, part of the U.S. National Institutes of Health, co-funder of the original study. They also reviewed other new publications on formaldehydes health effects, including studies showing that formaldehyde cant reach the bone marrow, where leukemia-causing effects are generally recognized to occur.

The findings in this reanalysis are important because they call into question the validity of all these recent formaldehyde assessments, said Kimberly White, senior director of the American Chemistry Council Formaldehyde Panel. The original paper failed to meet its own data quality standards and the scientific standard of reproducibility. Relying on it consequently led to unsubstantiated regulatory decisions and unwarranted outcomes. The EPA and other agencies evaluating chemical risk from exposures must consider the entire weight of evidence on formaldehyde when setting exposure limits.

For more information, visit ACCs web site.