[Date Prev][Date Next][Date Index]

E-M:/ MDEQ Significantly Weakens Risk Level Xylene



-------------------------------------------------------------------------
Enviro-Mich message from Jeff Gearhart <jeffg@ecocenter.org>
-------------------------------------------------------------------------

Michigan DEQ has significantly weakened the health risk-based 
exposure standard (also know as the initial threshold screening level 
(ITSL)) for the #1 emitted VOC in the state --mixed xylenes 
(including m-,o- and p-xylenes).

Both the exposure standard and the averaging time has been raised, 
going from 4400 ug/m3 with a 1-hr averaging time, to 100ug/m3 with a 
24-hr averaging time.

In 2000 total Xylene (mixed isomers) emissions in Michigan were 
6,532,805 lbs., more then double the next closest VOC.  Xylene is a 
major pollutant at literally hundreds of industrial facilities in the 
state.

This change and the EPA data supporting it bears close review by 
health advocates.  A summary of the data is located at 
http://www.epa.gov/iris/.

_________________________________________________________________
Subject:      The initial threshold screening level (ITSL) for xylenes
               (including m-, o- and p-xylenes) has been c
To:           DEQ-AQD-TOXICS_INFO@LISTSERV.MICHIGAN.GOV
X-OriginalArrivalTime: 01 Apr 2003 17:41:48.0392 (UTC) 
FILETIME=[F881E680:01C2F875]

The initial threshold screening level (ITSL) for xylenes (including m-,
o- and p-xylenes) has been changed from 4400 ug/m3 with a 1-hr averaging
time, to 100ug/m3 with a 24-hr averaging time.  The change in the xylene
screening level is based on a recent inhalation reference concentration
established by EPA and reflects new toxicological information that
wasn't available at the time when the 1-hr value was derived.  The new
ITSL was determined by the methodology specified in Rule 336.1232(1),
promulgated pursuant to Part 55, Air Pollution Control, of the Natural
Resources and Environmental Protection Act, 1994, PA 451, as amended.
Documentation for EPA's Inhalation RfC for Xylene can be found at:
http://www.epa.gov/iris/
-- 
_________________
Jeff Gearhart
Ecology Center
117 N. Division
Ann Arbor, MI  48104
(734)663-2400 x117
(734)663-2414 fx.

http://www.ecocenter.org
http://www.cleancarcampaign.org


==============================================================
ENVIRO-MICH:  Internet List and Forum for Michigan Environmental
and Conservation Issues and Michigan-based Citizen Action.   Archives at
http://www.great-lakes.net/lists/enviro-mich/

Postings to:  enviro-mich@great-lakes.net      For info, send email to
majordomo@great-lakes.net  with a one-line message body of  "info enviro-mich"
==============================================================