[CPEO-BIF] U.S. EPA proposes new PCE standards for dry cleaners

[Lenny Siegel <lsiegel@cpeo.org>]

U.S. EPA has proposed, in the December 21, 2005 Federal Register, a rule
establishing new National Perchloroethylene [PCE] Air Emission Standards
for Dry Cleaning. For more information, as well as to download the rule
as HTML or PDF, go to http://www.epa.gov/ttn/atw/dryperc/dryclpg.html.
EPA is taking comments on the proposed rule through February 6, 2006.

Much of the rule, proposed under the Clean Air Act, would update the
Maximum Achievable Control Technology standards. But in offering
assumptions about PCE toxicity, it also raises issues central to the
potential revision of PCE exposure limits as they apply to vapor
intrusion. PCE is currently considered a probable carcinogen, and the
exposures associated with a one-in-a-million excess lifetime cancer risk
seem lower than those used as a standard by states such as New York. (I
would appreciate confirmation or correction from someone who reads and
speaks toxicologyese.) The proposed rule's preamble says EPA is
reevaluating the toxicity of PCE, and the Integrated Risk Information
System (IRIS) web site (to which it refers) reports that External Peer
Review and Public Availability are due for completion on July 22, 2007.
(PCE is called tetrachloroethylene in the IRIS data base, found at http://cfpub.epa.gov/iristrac/index.cfm.)

Equally significant, the proposed rule offers two new options for
regulating dry cleaners in "co-residential" settings - structures
containing homes as well as dry-cleaning operations. EPA believes that
approximately 1,300 of the nation's 28,000 dry cleaners operate in
co-residential settings. Nine hundred are located in New York state, and
another 200 are in California. A New York study found that residential
PCE exposures in measured co-residential buildings ranged from a
geometric mean of 33 micrograms per cubic meter to a maximum of 5,000
micrograms per cubic meter.

New York already applies extra engineering requirements in
co-residential settings, and California's take effect in 2007. Under one
option, EPA would apply New York's engineering requirements across the
rest of the country. The other option is to outlaw the installation of
new PCE-based dry-cleaning equipment in co-residential settings. Because
that might encourage cleaners with existing PCE-based machines to
continue operating them beyond their normal useful lifespans, EPA is
also considering a requirement that existing equipment be phased out.

The elimination of PCE-based equipment from co-residential settings is a
more health protective, certain solution, so I favor that option. But
I'm not sure why EPA isn't going further. The continuing use of PCE in
non-co-residential settings will sustain emissions which elevate the
ambient concentrations of PCE in air and risk repeated releases of
liquid TCE into soil and groundwater. If I recall correctly, the
Southern California Air Quality Management District is encourage the
transition of dry-cleaning from PCE to less toxic substances. This is
beyond my expertise, but I don't understand why the proposed rule
doesn't do the same.

Communities have consistently questioned the releases of volatile
organic compounds - TCE, PCE, etc., - be they from vapor intrusion,
industrial use, or household products. Oversight of such emissions is
fragmented and in some cases, weak or non-existent. The proper way to
protect public health would be to conduct consolidated assessments of
all exposures to such chemicals as a major step forward in the
protection of public health from cumulative exposures.

Lenny Siegel

-- 


Lenny Siegel
Director, Center for Public Environmental Oversight
c/o PSC, 278-A Hope St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/961-8918
<lsiegel@cpeo.org>
http://www.cpeo.org
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