The following blog is a segment of a three part series regarding EPA’s Integrated Risk Information System (IRIS) program.
Part I: The Science
For years, scientists have investigated formaldehyde chemistry to help determine appropriate regulatory levels, safe exposure threshold levels, and whether there is any causal link between formaldehyde exposure and cancer. Since the 1990s, published research has consistently demonstrated that safe thresholds for formaldehyde exposure exist. Numerous peer-reviewed studies have been published and submitted to EPA. Moreover, these peer-reviewed studies have not found an association with cancers at environmentally-relevant human exposure levels.
Most recently, research by the University of North Carolina (UNC) clearly identified a scientifically-based safe formaldehyde exposure threshold. This cutting-edge research also confirmed the biological implausibility for formaldehyde to cause leukemia. The UNC research is revolutionary – differentiating between inhaled formaldehyde exposures from the environment and those that the human body is naturally producing. The result: UNC’s research is the most accurate measure supporting that current safe exposure limits are protective of human health.
However, scrutiny of formaldehyde continues, specifically around EPA’s draft Integrated Risk Information System (IRIS) assessment. Chemical assessments should be based on realistic assumptions and the best available scientific information. Unfortunately, the 2010 draft IRIS assessment proposed a value would set an acceptable air concentration that is significantly below levels that naturally occur in the environment and the human body (see figure below).
EPA’s assessments must incorporate and integrate all of the recent, state-of-the-art science that demonstrates an association with leukemia is not biologically plausible and documents safe thresholds for formaldehyde exposure. Several international agencies have used a threshold approach when setting safe exposure levels. For example, in 2010 the World Health Organization (WHO) recognized that a threshold based approach is appropriate for establishing indoor air quality guidelines for formaldehyde. More recently, in 2018, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) also recognized a threshold for formaldehyde exposure when establishing its values for safe long-term exposure. WHO has set protective indoor air guidelines for formaldehyde at 80 ppb. Typical household formaldehyde concentration levels are between 16 and 32 ppb.
The public needs to have confidence that EPA will set acceptable levels that are based on relevant, best available science, like that conducted by UNC. Poor-quality science can lead to unwarranted restrictions or product de-selection, unfounded public alarm, and unnecessary costs for consumers and business. The scrutiny should be on the IRIS program’s use of questionable science that can mislead the public about chemical risk.