Formaldehyde exposure limits - Take Your Pick

http://www.propublica.org/article/formaldehyde-found-in-houses-provided-for-katrina-victims-in-mississippi-12
Formaldehyde Found in Houses Provided for Katrina Victims in Mississippi...

"Earlier this month, a MEMA [?Mississippi Emergency Management Agency?] spokesman told the Biloxi Sun Herald that it still hadn’t conducted the promised testing. But documents obtained by the Sierra Club show that MEMA had in fact tested some of the cottages in April and found formaldehyde at levels between .046 parts per million and .116 parts per million.
The National Institute for Occupational Safety and Health recommends that workers should not be exposed to an average of .016 parts per million for more than 10 hours without wearing a respirator. FEMA adopted that standard for its trailers in April 2008, after a congressional investigation revealed that the agency avoided testing trailers for formaldehyde because of concerns about litigation.
In defense of MEMA, its executive director, Mike Womack, said the agency’s tests were designed only to determine whether factors like temperature, humidity, or the amount of time a unit was closed after shipment affected formaldehyde levels. He said the federal government has so many conflicting formaldehyde standards that it was hard for MEMA to determine which one to follow, especially since none of the standards apply specifically to formaldehyde levels inside homes."
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BrooklynDodger(s) comment: The issue of acceptible exposure levels for formaldehyde seems to surface only when a public agency is responsible for new construction or possibly newly insulated residences. This news story has moved from trailers to cottages. The Dodger(s) have previously noted that EPA appears to be working on a new risk assessment for formaldehyde, in response to a Section 21 TSCA petition by NRDC and others.

In the interest of a simple blog post, the Dodger(s) now supply the range of exposure limits:

The OSHA limits are a PEL of 0.75 ppm TWA, 2 ppm STEL, an action level which triggers monitoring and active medical surveillance of 0.5 ppm. In addition, exposures over 0.1 ppm and symptoms trigger employee training and an obligation for medical surveillance after complaints. In the formaldehyde standard, medical surveillance includes medical removal protection and multiple physician review.

The ACGIH® TLV for formaldehyde is 0.3 ppm ceiling limit, nearly tenfold more protective than the OSHA STEL.

The NIOSH REL for formaldehyde is 0.016 ppm for a 10-hour TWA and 0.1 ppm for 15 minutes.

The EPA Integrated Risk Information System (IRIS) does not include a “reference concentration” for formaldehyde, although it predicts a 1/10,000 risk of cancer at 7 ppb (likely for 24-hour exposure over a lifetime) based on laboratory studies.

Finally, ATSDR publishes several “minimum risk levels”: 0.04 ppm for acute exposure (1–14 days), 0.03 ppm for intermediate exposure (14–364 days) and 0.008 ppm for chronic exposure (365 days and longer). See www.atsdr.cdc.gov/mrls/index.html for more information.