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

Re: Green Earth drycleaning, D5 solvent

I wanted to respond to a question Eileen Sheehan posted, albeit two weeks 
late.  The short answer to your questions are:

1) According to GreenEarth LLC, about 300 drycleaning machines using D5 
(decamethylCYCLOpentasiloxane) solvent are in use at over 200 facilities.

2) The carcinogenicity of D5 is being retested. Results will be available 
in about 18 months.  The industry association (www.sehsc.com) knows the 
most about the toxicity status.  However, EPA OAQPS should be familiar with 
the performance of D5 and other drycleaning solvents from the review of the
drycleaning NESHAP that they are currently performing as required by 
112(d)(6) of the CAA.

Earlier this year a drycleaning industry trade association published a 
favorable report about the performance of D5, but around the same time the 
solvent's manufacturer, Dow Corning, received bioassay results indicating 
concern for potential carcinogenicity. The bioassay results may be found to 
be spurious upon retesting (considering that the iexposure level tested was 
500 times the peak occupational exposure of 0.3 ppm), but until new test 
results are available, D5 is a carcinogenic question mark (compared with 
perc which is a probable/possible carcinogen with definite chronic effects 
on the central nervous system).  Based on the initial bioassay, GreenEarth 
doesn't plan to
withdrawl from the market, but interest in D5 has dropped, particularly 
since hydrocarbon solvents like DF2000, with about 2000 machines, have 
become well-established.

TAPs in California are receiving inquiries about perc alternatives because 
of the South Coast Air District rule phasing out perc.  To encourage 
cleaners to purchase machines using alternative solvents, South Coast also 
provides $5000 grants for DF2000 machines or $10,000 for 
wetcleaning.  Since the toxicity test results were disclosed, grants are no 
longer available for
D5 machines.

Regarding Nancy Larson's follow-up question about subjecting GreenEarth 
cleaners to the same requirements as hydrocarbons, both DF2000 and D5 are 
exempt from the NESHAP. D5 is listed as a non-VOCs based on its low 
photochemical reactivity. VOC emissions with DF2000 are very low.   DF2000
has a lower flash point than D5 which makes it a fire code concern.

In terms of cleaning performance, both DF2000 and D5 are roughly the 
same.  Perc is a stronger solvent, but its strength can dissolve adhesives, 
buttons, etc. A machine for DF2000 or D5 costs about $8,000 - $10,000 more 
than a PCE machine.

CO2 machines cost about twice as much as machines using other solvents, and 
have not demonstrated comparable cleaning quality.

A new solvent, PureDry, which has over 50 machines in the U.S., has 
generated a lot of interest.  PureDry is a hydrocarbon like DF2000 with 
additives to raise the flash point and improve the solvent power. Early 
formulations of PureDry experienced difficulty maintaining a high flash 
point with use, but this problem may have been overcome.  PureDry isn't 
much different than DF2000, just less flammable and a little more expensive.

Wetcleaning is a viable replacement for perc.  Many cleaners have a small 
capacity wetcleaning machine, but only a dozen or so have switched 100%, 
partly because they're unconvinced that it can clean everything, partly 
because they haven't needed to switch, and partly because it takes more
labor.  But even a 50% switch would make a big reduction in perc use.

Based on P2 or health concerns over perc alone, few cleaners are likely to 
be motivated to switch solvents.  (Site remediation concerns are a bigger 
concern.  All of the alternative solvents are much better than perc because 
they're biodegradable and not on any analyte lists.) Even cleaners who
have switched, usually don't publicize it to their customers, because for 
every customer who is concerned about the health effects of perc, 99 don't 
know or care.  Most cleaners don't want to do negative advertising about 
the rest of the industry. In the words of an industry trade journal, 
"Customers expect cleaners to be environmentally responsible regardless of 
what solvent they're using." If you want a better idea of the industry 
attitude about switching solvents, see page 23 of 
www.nca-i.com/julyaugust2002.pdf for the whole article. It's a long 
download, not unlike this post.

H. Harold Bruthzoo
Bruthzoo & Associates

-----Original Message-----
From: owner-p2tech@great-lakes.net
[mailto:owner-p2tech@great-lakes.net]On Behalf Of
Sent: Tuesday, July 22, 2003 14:24
To: p2tech@great-lakes.net
Subject: Green Earth drycleaning, D5 solvent

I'm curious if those of you who work with drycleaners are 1) seeing
drycleaners convert to Green Earth solvent
(D5=decamethyloctapentasiloxane), and 2) aware of the new data EPA has
received on D5?  I've received calls from several TAPs asking me about
the new data submitted to EPA in February and suggesting I post this on

D5 is marketed under the name Green Earth and is a volatile methyl
siloxane.  D5 is also used in various solvent cleaning operations not
just drycleaning.

EPA HQ  recently received some new information about D5/the Green Earth
drycleaning solvent. The data was filed under the TSCA Section 8(e)
docket - a notice of "substantial risk of injury to health or the
environment."  The preliminary results of an ongoing 24 month combined
chronic/oncogenicity study of D5 in rats indicates an increase in
uterine endometrial tumors for rats exposed for 12-24 months. See
the actual submittal to EPA.

EPA's Office of Prevention, Pesticides and Toxic Substances reviewed
new data at the request of California's Office of Environmental Health
Hazard Assessment and issued a statement that "At this time, the
results of this study indicate there is a potential carcinogenic hazard
associated with D5."   Dow Corning, which submitted the data to EPA
under an MOU called the Siloxane Product Stewardship Program, is
continuing further work.

Eileen Sheehan
Pollution Prevention Team
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA  94105
Ph: 415 972-3287

MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
p2tech is hosted by the Great Lakes Information Network:
To unsubscribe from this list: send mail to majordomo@great-lakes.net
with the command 'unsubscribe p2tech' in the body of your message. No
quotes or subject line are required.
About : http://www.great-lakes.net/lists/p2tech/p2tech.info
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *