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

RE: Parts Washers

Hi Robert,

I'm interested in knowing how much brake cleaner was used to preclean the
parts.  This activity has been down played by the SCAQMD in promoting
aqueous cleaners.  It doesn't seem to make much sense if you replace a
solvent-based parts washer with an aqueous unit and still need to preclean
with solvents.  Brake cleaner is more toxic than the solvents replaced and
none of this solvent is recycled.

The use of brake cleaner over the bath also impacts the handling of the
waste.  I know the spent baths must be handled as hazardous, but how ?  Is
it sent to a cement kiln for incineration.  Conventional wastewater
treatment would not be appropriate for a bath contaminated with PERC.

And then there is the issue of corrosion inhibitor.  Do you know what is
being used ?  Chromates and nitrites were at one time common.  The residue
left on the parts can be toxic and cause contact dermititis.  Were users
instructed to wear gloves even when handling dry parts ?  I'm interested in
hearing how these issues were addressed.

> ----------
> From: 	RLUDWIG@hw1.cahwnet.gov[SMTP:RLUDWIG@hw1.cahwnet.gov]
> Reply To: 	RLUDWIG@hw1.cahwnet.gov
> Sent: 	Monday, August 03, 1998 6:30 AM
> To: 	p2techsuperiorgreat-lakesnet
> Subject: 	Parts Washers
> I was a partner in the study done by Katy Wolf and Mike Morris of IRTA
> evalua-
> ting Water-Based Cleaners in the Auto Repair Industry.  I am with the
> Office of
> Pollution Prevention and Technology Development in the Dept of Toxic
> Substances
> control.  Other partners included the south Coast Air quality Management
> District(SCAQMD) and the City of LA's  Bureau of Sanitation. After this
> project
> was initiated,  SCAQMD started to evaluate whether to change an existing
> air
> regulation, Rule 1171, that would require the use of cleaning
> materials containing no more than 50 grams of volatile organic compounds
> (VOC) per liter.  As it turned out, SCAQMD changed the regulation to
> require
> just that which will go into effect 1/1/99.
> Overall, Katy and mIke found that water-based cleaners worked effectively
> in
> auto repair shops and were a viable option to mineral spirits.  They
> tested
> the
> traditional sink-on-a-drum remote reservoir configuration, an immersion
> system
> with a false sink, an enzyme unit, and a spray cabinet.  The units were
> made of
> steel, plastic, or stainless steel with a reservoir size from 15 - 40
> gallons.
> Tradeoffs:  the water must be heated to make the cleaners more effective.
> this
> means increased electrical costs.  Temperatures of 110 degrees F are
> common in
> the immersion units and higher temperatures -- ranging from 140-180 F--
> are
> used in the spray cabinets.  Mechanical action is more important in water
> cleaning than mineral spirits.  Most of the water-based immersion systems
> need
> stronger pump pressure for mechanical action. The spray cabinet delivers
> pres-
> sure of 15-60 psi.
> Corrosion of parts was not a problem because there are rust inhibitors in
> the
> water based cleaners.  Drying of parts was not considered a problem.
> Katy's
> study was a test and demonstration project during a time when  there were
> not
> many cleaning units available but still, most of the participants in the
> study
> found that the units did a good job when the proper concentration of
> formula-
> tion was used, i.e., 25-30 percent in immersion equipment and 10-15
> percent in
> spray cabinets.  The equipment is now second generation, not traditional
> mineral spirit sink-on-a-drums with an add on heater, which means they are
> designed for water usage and thus work more efficiently.
> One of the big pluses of using the aqueous cleaning systems is that
> workers
> are
> not exposed to mineral spirits via respiratory or dermal routes.  Also,
> with
> water-based systems that are formulated to reject oil, the oil can be
> removed
> and the life of the bath can be extended beyond what if could be for
> mineral
> spirits as the oil dissolved in mineral spirits eventually renders it
> useless
> as a cleaner.      Also, there does not appear to be a need to use an
> aqueous
> cleaner  with any VOC additives as they seem to work fine without them.
> As to the management of the spent aqueous cleaning systems, there are a
> number
> of issues that must be addressed.... at least here in California.  The
> major
> waste streams include the spent aqueous cleaners, oil skimmed from the
> units,
> and the oil filters removing the oil from the units to extend the bath
> life.
> Based on the lab results from Katy's study it was determined that most of
> the
> time the spent aqueous cleaner will be considered a hazardous waste (RCRA
> and
> non-RCRA, i.e., California only wastes) due to metals.  Other contaminants
> include PERC, xylene, and toluene from aerosal cans of brake cleaners used
> over
> the aqueous cleaning systems that end up contaminating the baths.  So, in
> CA
> the spent aqueous based cleaners must be manifested as a hazardous waste
> and
> hauled by a registered hazardous waste transporter who must then deliver
> it a
> TSD facility. This was routinely done before by the service delivering the
> mineral spirits and picking up the old spent mineral spirits for recovery.
> The oil filters were determined to be hazardous most of the time due to
> metals.
> So, these must be manifested and managed as a hazarous waste.  The oil
> removed
> from the aqueous cleaning systems however can be picked up by an oil
> recycler.
> The sludge in the bottom of the cleaning units was also found to be
> hazardous
> due to metals and would also have to be managed as a hazardous waste.
> If anyone would like to receive a copy of the IRTA report entitled "Parts
> Cleaning in Auto REpair Facilities: The Conversion to Water" Executive
> Summary
> #613, or the report (same title) #614 please send    your mailing address
> via
> fax (916)327-4494 or e-mail to Robert Ludwig, OPPTD/DTSC, P.O. box 806,
> Sacramento, CA 95812-0806.  If you have any questions, give me a call at
> (916) 324-2659.The raw laboratory data is available but since there are
> only
> a limited number, you will have to convince me why you need a copy.
> Best regards,
> Robert Ludwig
> E-Mail:  HW1.RLudwig@ HW1.CAHWNET.GOV
> *** Forwarding note from OWNERP2T--HWSMTP   07/31/98 11:11 ***
> To: p2tech
> Subject: Parts Washers
> Sender's Nativename=owner-p2tech@superior.great-lakes.net
>     There appears to be some options between the extremes of LOW FLASH
>     solvent based cleaners and aqueous cleaners.  The low flash
>     cleaners seem to be preferred but are generating hazardous waste
>     and emissions.  The big complaint with aqueous cleaners, as
>     mentioned in another message, is that they can create other
>     problems...corrosion on parts, slow drying time, poor cleaning
>     ability, etc.
>     I would like to point-out some middle road options, as well as
>     advocate keeping one eye on new cleaning solutions.  An important
>     element is the specific use for which the cleaning solution is
>     needed.  One should definitely take this into account...even
>     aqueous solutions can become a hazardous waste in some situations.
>     There are some high-flash (>140) solvents that reportedly perform
>     very well and MAY eliminate the need for hazardous waste
>     management.  (Sorry but I don't have specifics.)  There are
>     reportedly solvent blends that accomplish the same purpose, again
>     pending actual use.  I would think that the higher flash solvents
>     help to minimize VOC's.  HAP's may be another issue on which to
>     keep one eye.
>     If there are multiply units in a facility NOT being used for the
>     same purpose, there may be an option on using different cleaning
>     solutions.  Also, if multiple units are employed, there may be
>     options for reducing both the size and number of units, and
>     resulting emissions.
>     Change-out frequency can also be a problem if performed routinely.
>     Unit usage should be evaluated to determine if monthly change-outs
>     are needed, or perhaps a longer service interval.  In several
>     cases, users extended change-outs to nearly double usage, and one
>     facility extended change-outs from every 4 weeks to nearly three
>     months.  (I'm not quite sure how beneficial this may be for
>     emission reduction, but I'd like to think it is a positive
>     direction.)
>     Some units are available with built-in filters that reportedly
>     extend the useful life of the cleaning solution.  One type of unit
>     reportedly only requires periodic filter changes and the addition
>     lost fluid.  Although I've heard the claim the filters can be
>     managed as non-hazardous, I still believe the actual usage would
>     determine the status of the filter.  Again, emission reduction
>     still may be an issue.
>     I realize much of this does not address VOC issues.  On a larger
>     than parts-cleaner scale, GE Transportation Systems, in Erie PA,
>     eliminated a solvent-based cleaning station (for train engines) in
>     favor of an aqueous-based cleaning system.  VOC minimization was
>     one of the benefits.  You may get additional information from the
>     facility.
>     Ric
>     illig.richard@a1.dep.state.pa.us