From: Bruce Van Scoy <brucev**At_Symbol_Here**BRIGHT.NET>
Subject: Re: [DCHAS-L] Overspray from screen print cleaning
Date: January 31, 2012 8:31:18 PM EST
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: <1327789644.94822.YahooMailNeo**At_Symbol_Here**>

Debbie - If the water spray and particulates are non-hazardous and there is no potential for occupational exposure, have you considered educating the shop manager to alleviate his/her concerns? A famous quote is "the dose makes the poison" and it just seems to me that we should be educating people to be concerned about the hazards that are indeed hazardous and satisfy them with those issues that are not, maybe a little training could go a long way.


Ron - Waste has to be profiled to meet EPA discharge regulations or disposal regulations. Debbie was speaking of an occupational exposure governed by OSHA, not EPA. Different standards/criteria, an apples to oranges comparison. You stated that your discharge is a non-hazardous waste. How was the information presented to the city? Was the waste stream properly characterized for disposal? Characterization is required to be performed by a lab that is probably outside of your company, but certified by your state/Fed EPA. Homeowners or retail consumers have always been and always will be exempt from EPA compliance requirements, while we are not. Your city was/is right in that they have the final say in what they will accept into their wastewater treatment facility and if not sufficiently defended with analytical results. Your city does not want to treat a hazardous waste or be classified as a Treatment, Storage or Disposal Facility (TSDF)? You can make this a win-win situation. Do you have a permit, maybe even an industrial wastewater discharge permit from your city?

If not I would recommend that you investigate the requirements and obtain one. Either way you will need the lab analytical results to present to them. Yes, this will require initial laboratory analytical confirmation, continued on a recurrent basis, for them to continue to accept the wastewater discharge into their sewer system and that is the point, that's compliance and yes, violations can/will lead to expensive fines/penalties in California or anywhere else.

The location is irrelevant they are implementing the federal law!




From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Ronald Andrus
Sent: Saturday, January 28, 2012 5:27 PM
Subject: Re: [DCHAS-L] Overspray from screen print cleaning


I have concern with the following statement that you made "The cleaning process occurs in the shop in a large, stainless steel sink, installed against one wall in the shop.  The sink is fitted with a solids trap.  All of the emulsions, inks and strippers are water-based, don't have any hazardous materials in them and are allowed to go down the drain."  I am the Chemical Hygiene Officer for a paint manufacturing company.  Our company desired to discharge some non-hazardous waterborne waste into the sewage system.  Our company was advised by the city that to dump the water directly into the sewer system our company must have the representative material analyzed by an outside firm.  The analysis would be submitted to the sewage treatment agency for approval.  If approved for discharge to the sewer system, our company would receive a permit to do so.  Then periodically our company would have to do random testing to confirm that the same quality of discharge water was the same.  A retail consumer is permitted to directly discharge to the sewer system.  As a business any waste that is generated by any of your business processes is considered industrial waste.  Violation can lead to fines which especially in California can add up quick.


Very Respectfully,

Ron Andrus

Chemical Hygiene Offcier

Matrix System Automotive Finishes, LLC


From: Don Abramowitz <dabramow**At_Symbol_Here**BRYNMAWR.EDU>
Sent: Friday, January 27, 2012 11:33 PM
Subject: Re: [DCHAS-L] Overspray from screen print cleaning


Assuming the overspray is simply a nuisance and local exhaust is truly unnecessary, perhaps you could place particulate filters over the return air intakes.  This could be as crude as taping air handler, furnace, or paint booth overspray filters over the openings, or having metal filter holders installed over the intake to make filter changes easy.  Could even add magnehelic guages to monitor the differential pressure to know when it's time to change the filters.   This should keep the material out of the system, as long as there are no volatiles involved that would be a concern if they passed through or  evaporated off the filters and were drawn into the system.


Donald Abramowitz, CIH
Environmental Health & Safety Officer
Bryn Mawr College
Bryn Mawr, PA



Please excuse the cross-postings - I need to cast a wide net.


Our Design department has moved into new digs in a renovated older building (early 1960's vintage).  It has a return air system with openable windows.


In the screen printing shop, they treat the screens with an emulsion and various inks to form the image.  After they develop the image and use the screen, the dried ink and emulsion need to be removed from the screen.  They use a stripper and power washer to clean the screens.  The cleaning process occurs in the shop in a large, stainless steel sink, installed against one wall in the shop.  The sink is fitted with a solids trap.  All of the emulsions, inks and strippers are water-based, don't have any hazardous materials in them and are allowed to go down the drain.


But the cleaning process puts water spray and particulate into the air - in a return air building - and my shop manager is concerned about occupant exposure and contamination of the supply air from the overspray.  Adding exhaust ventilation isn't possible, for a variety of reasons.  Cleaning the screens outside isn't possible either, as there are strict storm drain rules in California.  There haven't been any complaints yet but they just moved into the space last quarter.


Any ideas?  I'm fresh out.






Debbie M. Decker, Campus Chemical Safety Officer
Environmental Health and Safety
University of California, Davis
1 Shields Ave.
Davis, CA  95616
(530)754-7964/(530)681-1799 (cell)

(530)752-4527 (FAX)
Co-Conspirator to Make the World A
Better Place -- Visit and join the conspiracy




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