Inhalation Unit Risk Factor (IUR) for Acrolein
OEHHA is releasing a draft document for public review that summarizes the carcinogenicity data and derives a cancer inhalation unit risk factor (IUR) for acrolein.
Cancer IURs are used to estimate lifetime cancer risks associated with inhalation exposure to a carcinogen. Information on acrolein levels in the air can be found at the California Air Resources Board’s Acrolein FAQ Page.
Public Comment Period
The public review period for the draft updated acrolein IUR begins on May 14, 2026, and is scheduled to end on June 29, 2026. To submit comments electronically, please click below:
Public Workshops
OEHHA will hold three workshops to provide the public with an opportunity to ask questions and provide public comment about the cancer IUR for acrolein.
Northern California – in person and virtual
June 2, 2026, 4:00 PM – 7:00 PM
Sierra Hearing Room, CalEPA Headquarters Building
1001 I Street, Sacramento, CA 95814
Zoom Webinar Link
Southern California – in person
June 4, 2026, 11:00 AM – 1:00 PM
Auditorium, Ronald Reagan State Building
300 South Spring Street
Los Angeles, CA 90013
Central California
Details will be announced at a later date
Background on the Air Toxics Hot Spots Program
The Air Toxics "Hot Spots" Information and Assessment Act (AB 2588, Connelly) was enacted in 1987, and requires stationary sources of pollutants to report the types and quantities of certain substances routinely released into the air. The goals of the Air Toxics "Hot Spots" Act are to collect emission data, to identify facilities having localized impacts, to ascertain health risks, to notify nearby residents of significant risks, and to reduce those significant risks to acceptable levels. OEHHA is legislatively mandated to develop guidelines for conducting health risk assessments under the Air Toxics Hot Spots Program (Health and Safety Code section 44360(b)(2)). In response to this statutory requirement, OEHHA developed a Technical Support Document that describes the methodology for deriving inhalation unit risk factors and cancer slope factors for carcinogenic Hot Spots air pollutants. The methodology in the Technical Support Document explicitly considers possible differential effects on the health of infants, children, and other sensitive subpopulations under the mandate of the Children’s Environmental Health Protection Act (Senate Bill 25, Escutia, Chapter 731, Statutes of 1999, Health and Safety Code Sections 39669.5 et seq.), including procedures for evaluating increased susceptibility to carcinogens.