OEHHA proposes tighter exposure limits

By CMTA Staff

Capitol Update, Dec. 14, 2007 Share this on FacebookTweet thisEmail this to a friend

In early November, California’s Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) issued a draft document which sets the stage for dramatic regulatory changes at facilities subject to local district air toxics programs.  Facilities subject to the air toxic hot spots program (AB 2588, Lloyd Connelly, D-Sacramento, 1987,) and local district air toxic new source review programs particularly need to take notice.  

The proposal changes the way risk assessments are done for developmental and reproductive toxins in response to SB 25 (Martha Escutia, D-Montebello, 1999), and includes new "reference exposure levels" (RELs) for six chemicals (acetaldehyde, acrolein, arsenic, formaldehyde, manganese and mercury).  The REL is the exposure level below which adverse effects are not expected to occur in the human population, including sensitive subgroups (defined in SB 25 as infants and children).  

OEHHA acknowledged during a public workshop last Friday, December 7, that in some cases the new risk assessment methodology would lower existing safe exposure levels by as much as 30 times.  For certain chemicals, such as manganese, OEHHA proposes to apply arbitrary uncertainty factors to meet their SB 25 mandate, despite the fact that the existing RELs already account for sensitive populations and without regard to available scientific data which argues against the use of such extreme numbers.

OEHHA’s proposal breathes new life into programs that have been operating in maintenance mode for more than a decade.  Many facilities will be required to conduct new risk assessments.  Some will be required to notify surrounding communities that they are being exposed above a level the district has determined to be a "significant risk".  Other facilities making modifications may see their permit applications denied.  The changes to the risk assessment methodology and the proposed RELs will also influence decisions in other regulatory programs (development of drinking water standards, site cleanup levels, for example).  The changes will spotlight affected chemicals, raising new safety concerns and will probably prompt political reactions.

Currently, comments on the draft document are due to OEHHA by January 2.  However, CMTA and others are requesting additional time for review and comment because the time frame falls during the holidays leaving little opportunity for meaningful comment.  

CMTA would appreciate receiving our members’ comments concerning the impact on operations if this document is approved.  Please contact Mike Rogge at mrogge@cmta.net

OEHHA’s agenda notice and proposal: www.oehha.ca.gov

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