In response to Mike Callahan's 8/24/01 inquiry asking why the EPA may not like the controlled spraying program: The EPA sent a letter to the Composites Fabricators Association on April 29, 1998 responding to CFA's request that the EPA Office of Compliance & Enforcement evaluate and comment on the enforceability of the CFA's controlled spraying program. I believe CFA suggested that the controlled spraying program be added to the list of emission reduction techniques being considered in the draft MACTstandards for open molding sources. EPA stated that: "Based on our analysis of all of the information available, the Agency's position continues to be .. that the controlled spraying program would not be practically enforceable."
Some reasons given in the letter were: (1) the program has many variabilities including product surface areas, skill levels of technicians, % transfer efficiency during spraying, etc. , (2) there is not a practical way to quantify emission reductions which is necessary to issue credits for the MACT program, (3) additional monitoring, recordkeeping and reporting requirements would be necessary and there would be a burden in maintaining detailed records, especially for small businesses.
The folks at CFA or EPA may be able to state if there has been any additional discussion on this subject.
"Callahan, Mike" <Mike.Callahan@Jacobs.com> 08/24/01 04:28PM >>>
Thanks for bringing this great website to everyone's attention. Do you have any background on why the EPA won't allow the use of controlled spraying? I think that the CFA is right on the money with this one. Training is one of the most important factors in reducing emissions from any spray coating operation. I just read one of the CFA reports and I fully agree that emissions reduction can be achieved through training and by controlling the spray so you don't coat areas you don't want to coat. This is the one big error of all transfer efficiency tests.
My guess is the EPA would prefer to maintain a command and control approach because it is easier to enforce. We ran into this in the automotive refinishing industry where the air agencies insisted on the conversion from air spray to HVLP spray guns. While available data at the time showed potential reductions to be the same for HVLP versus conventional air spray with training, the push to HVLP went on. I hope the CFA has better luck. Just my two cents.
From: Bill Quinn [mailto:Quinn.Bill@ev.state.az.us]
Sent: Friday, August 24, 2001 2:10 PM
Subject: Re: Fw: Styrene
Since your note did not state what manufacturing methods the bathtub/spa manufacturer uses now (i.e. are they casting cultured marble and using gelcoat or just using fiberglass and resin/gelcoat, I will generalize here.
The EPA's AP-42 emission factors for polyseter resin products fabrication were withdrawn on 3/18/1998 and have not yet been replaced. Section 4.4 of AP-42 was removed because the emission factors presented in that section appeared to under predict styrene emissions from most polyester resin operations. Many Arizona shops are now using Arizona's Maricopa County emissions factors for polyester resins which are currently based on the Composites Fabricator Association's (CFA) emissions tables. The exception is that the EPA has said they will not allow use of the column for "controlled spraying." The CFA table can be seen as Table 2.16 in the document located at http://www.epa.gov/ttn/chief/efdocs/cfa_rpt3.pdf
This table is helpful if one wants to be able to calculate a styrene emission reduction because it shows the allowable P2 techniques. As seen on the table hedings, to reduce styrene emissions, one can use vapor supression, change to a non-atomized application instead of a spray gun, use a manual resin application, use a resin or gel coat with less styrene %, or change to a closed molding process.
Judith Kennedy already responded with very helpful information and websites to review.
In my experience here, the best emission reduction one can do in open molding is to install a resin flow coater/chopper to replace a spray/chopper gun. This works if your are using resin and fiberglass chop. It is not used here for gel coat. This flow coater application would be used only of the facility is using chopped fiberglass in their products. For cast cultured marble operations, some Arizona faclilties use chopped fiber glass on the back of their cast cultured marble products for strength and to lighten the marble casting.
Another possibility is to use a resin or gel coat with a lower % of styrene, but you must be careful to not degrade the finished product. One of our Arizona facilities (Arizona Marble) is using a manually applied gel coat or brushable gelcoat (product code G1117, distributed by HK Research Corporation, 38% styrene) on flat surfaces.
Lastly, Judith mentioned controlled spraying. A facility can easily implement the controlled spraying program developed by CFA. EPA does not allow an emissions reduction for such a program, but it does make sense to implement this simple program. This program involves (1) simple spray operator training, (2) proper spray gun pressure calibration, and (3) use of flanges on molds to reduce overspray. This program can be downloaded from the bottom of the page at: http://www.cfa-hq.org/techsvcs.shtml
The download includes an instructor guide and a student handbook.
It is important to also review the ventilation system and spray booths to be sure it they are designed and operated properly to protect public and worker health.
There are several other EPA documents on this subject that are worth noting:
EPA/600/SR-97/018, September 1997: Evaluation of pollution prevention techniques to reduce styrene emissions from open contact molding processes.
EPA/600/SR-96/138, December 1996: Evaluation of styrene emissions from a shower stall manufacturing facility.
EPA/625/7-91/014, October 1991: The fiberglass-reinforced and composite plastics industry
These may still be available at http://www.epa.gov/ncepihom/catalog.html
Pollution Prevention Unit
Pollution Prevention Unit
>>> "Kevin Dick" <firstname.lastname@example.org> 08/17/01 03:13PM >>>
I received a request to forward this to these listservs from a non-listserv
subscriber. In addition to a listserv reply please reply directly to:
> I am working with a bathtub/spa manufacturer that uses gelcoat and
fiberglass to manufacture these products. There is an odor (assumed health)
problem with their manufacturing and curing processes. The odor is from
primarily the styrene. The question is does anyone have experience/examples
of P2 techniques (IE product substitution etc.) that would reduce or
eliminate these chemicals? They have activated carbon control on 3 of their
4 stacks, but the real problem is the chemicals and what is being emitted
into and outside of the building .
> Tough question I know. Thanks in advance for any assistance.
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