Compliance and Safety at a Metal

Fabrication Shop

Jeff Stubbs

(603) 749-9904

X-L Corp. and Spraytek Corp.

25 Progress Ave

Nashua, NH 03062

contact: Bob Fay

(603) 889-0232


EXECUTIVE SUMMARY

There are a few different projects that I worked on at X-L and Spraytek. The major project and the one that I spent most of my time on dealt with cleaning the parts prior to cleaning. Spraytek now uses trichloroethylene (TCE) in a vapor degreaser to clean their parts. Since TCE is listed as a hazardous air pollutant (HAP) by the Clean Air Act Amendments of 1990 (CAAA) its use will be regulated strictly as of Dec. 2, 1997. To prepare Spraytek for these new regulations I have determined several options that will allow Spraytek to ensure that they will be in compliance. These options are to 1) install some new control devices on the degreaser to reduce the emissions or 2)use an alkaline aqueous cleaner to replace TCE in parts cleaning or 3) replace TCE with an aqueous cleaning/phosphating solution. The project results section of this report lists each of these options, what is involved with each option and the advantages and disadvantages of each option.

Some other projects I have been working on deal with aluminum dust collection and disposal, improving the cleanliness and safety in lead working operations, and obtaining a permit for the recently installed chrome plating line. The aluminum dust disposal problem pertains to sludge from a wet type dust collector that is a mixture of steel, stainless steel and aluminum dusts and water. If the sludge is too wet when it is put into the 55 gallon disposal drums a reaction between the aluminum and water gives off hydrogen gas and heat. This causes the drums to get smoldering hot and can remain that way for days. To avoid this the sludge is now allowed to dry out on screens before being put into the drums. The sludge is then sent to a company in Louisiana who uses it in mixing cement. The lead working operations are confined to one room ( the "lead room") to reduce employee exposure. Aluminum and lead dusts accumulate on tables and floors in the lead room. This causes health and safety considerations because lead is a health hazard and aluminum dust is explosive when stirred up into a cloud. X-L has two options in this case. One option is to purchase an expensive explosion proof vacuum that is equipped with a HEPA filter to clean up both types of dusts. Another option is to eliminate the creation of aluminum dust in the lead room so that a standard vacuum with a HEPA filter can be used to clean the lead room. I have also completed the limited permit application form for the chrome plating line. When they receive the results of a TCLP analysis for metals for the wastewater stream that is put into the evaporator X-L will send this along with the application form to the Waste Management Division at the DES.

INTRODUCTION

X-L and Spraytek Corporations run a small sheet metal fabrication operation in which they produce a variety of metal parts. The two companies are located next door to each other in the same building. Most of the parts that are made at X-L are painted by Spraytek. Spraytek also does jobs for other companies. In order to comply with regulations and increase the safety of their facility they are interested in changing the way certain steps are performed during the production process.

The major project that I worked on dealt with the degreasing step during the preparation of the parts for painting. Spraytek now uses TCE in a vapor degreaser to clean the parts. After cleaning the parts are primed using a wash primer. This step gives the parts a coating that ensures that the paint will adhere well to the parts. The parts that are being cleaned are steel, stainless steel and aluminum and range in size from small parts that would be loaded into a basket to large beams that actually extend out of the top of the degreaser. The contaminants that need to be removed from the parts are mainly cutting oils and coolants (both water soluble and non-water soluble), grease and fingerprints. TCE has been designated a HAP and as of Dec. 2, 1997 anyone using it will be subject to strict regulatory and reporting requirements. This means that some changes must be made by Spraytek in order to either comply with the regulations or not be subject to them at all. Some requirements that a cleaning/degreasing process must meet in order to be suitable for Spraytek are that the parts are cleaned adequately, the cost of the process is not too great, the parts don't rust and that they are dried during the process. I have determined several options that Spraytek has that will meet these requirements and allow them to comply with regulations that do not require an overly large initial investment.

Other projects that I have spent some time on deal with Aluminum dust disposal, cleanliness and safety in the lead room and permitting for the recently installed chrome plating line. The problem with aluminum dust arises during the collection and disposal of aluminum, steel and stainless steel dusts that are generated during the grinding and vibrating of sheet metal pieces. The dusts are collected by a wet-type dust collector and settle to the bottom of a tank of water. The sludge is then removed on a conveyor and put into 55 gallon drums for disposal. The problem results from a reaction between the aluminum dust and water that evolves hydrogen gas and heat. These drums had been getting extremely hot and staying that way for days. Occasionally they had even caught fire. Also, if the hydrogen gas was able to accumulate there would be an added risk of explosion. X-L wanted to find a way to dispose of this sludge without these hazards.

The concern in the lead room is over lead and aluminum dusts that accumulate on the floor and tables during the vibrating of lead and aluminum sheets. This is a concern because accumulating lead increases the amount of lead that is carried out of the room on employees, their clothing, or equipment. As it is now, the levels of airborne lead are well below OSHA standards but if this dust is stirred up into a cloud the lead could be inhaled and the aluminum could be ignited if an ignition source is present. The clean up of this dust had been done using a sweeping compound but this method is not preferred and it made the waste more difficult to dispose of because it is mixed with the sweeping compound. Therefor, X-L was in need of an effective way to keep the lead room free of accumulating dust. The method they choose would have to be able to clean all surfaces, including walls, tabletops and machinery, it must minimize the risk of re-depositing the lead into the workplace, and it must eliminate the risk of explosion from the aluminum dust.

The last project I worked on was to gather information on the chrome plating line including information on the evaporator, what is put into the evaporator, and the releases/wastes generated by the process. This information was used to fill out the limited permit application form which will be sent to the Waste Management Division of the DES. I had hoped that I might be able to work on increasing the efficiency of the painting operation to reduce waste and also reduce the number of paints used that contain carcinogens. This could have been done by consolidating the paints that are similar in color and replacing the paints that contain carcinogens with others that do not. Unfortunately I did not have tome to get to this and even if I had it would have been difficult to obtain significant results. The reason for this is that most of the types and colors of paints that Spraytek used are specified by their customers and are not under their control.

GOALS AND OBJECTIVES

Degreasing / Paint prep.

- if possible, eliminate the use of TCE

- clean parts effectively without leaving a residue or rusting the parts

- parts must be dry after cleaning

-utilize existing degreasing equipment to save money and facilitate conversion

- comply with CAAA National Emission Standards for Hazardous Air Pollutants (NESHAP)

- increase worker health and safety

- reduce pollution

Aluminum dust disposal

- dispose of sludge in a way that eliminates hot smoldering sludge as well as the risk of fire or explosion

Lead Room

- keep room free of lead and aluminum dust (including floors, walls, tabletops and equipment)

- minimize the risk of re-entry of lead into the workplace

- eliminate the risk of igniting an aluminum dust cloud

- increase worker health and safety

Chrome Plating Line

- gather required information and fill out documentation to obtain a permit for the new process line

APPROACH / METHODOLOGY

The first thing I did when I started at X-L and Spraytek was to familiarize myself with each operation that was related to my projects and the people involved with each operation. For the degreasing/paint prep operation this consisted of determining the types of parts that were being cleaned, the work load that is put through the degreaser, what contaminants were being cleaned off the parts, and how the machines were operated. I did this by talking to people at the facility and obtaining the degreaser manuals and the records of TCE use. My next step was to learn as much as I could about the NESHAPs for solvent degreasers. I did this by attending a Teleconference on compliance strategies for solvent degreasers and reviewing the booklet from this conference along with some additional information provided by the DES. At this point I was able to determine what would need to be done in order to comply with the new regulations if Spraytek decides to continue using TCE. I then contacted several companies selling degreasing equipment to get information and prices for emission control devices such as freeboard refrigeration devices ("chillers) and hoists.

At this point I focused my attention to finding an alternative to cleaning with TCE. I went to the library to get some general information on aqueous cleaning and began working with Amanda Heath on the SAGE program (Solvent Alternatives Guide). The results from SAGE included ratings on the suitability of different types of cleaners and different types of processes based on Spraytek's cleaning requirements. Amanda also sent me a list of aqueous cleaners and alternative solvents and the companies that sold them. Based on the SAGE results and Spraytek's cleaning needs I determined which of the cleaners might be suitable and contacted companies to request information on them. Based on the information provided by these companies I requested samples of the cleaners that seemed promising and performed some tests. For these tests I used two buckets, one for a wash tank and the other for a rinse. I used steel, stainless steel and aluminum pieces that I dirtied with contaminants that were typical at Spraytek. The wash solution was mixed to the suggested concentration and heated to 140 F. The dirty metal pieces were put into the wash bucket and agitation of the bath was begun. After ten minutes in the agitated wash bath the pieces were removed, rinsed and dried, and the results were recorded. Based on these test results, the product information and the cost of each cleaner I was able to narrow the list down to two aqueous alkaline cleaners.

Shortly after I finished testing the cleaners a salesman who was visiting Spraytek mentioned that there were water based cleaning/phosphating solutions available that would eliminate the need to use TCE as well as eliminating the wash priming step. This step uses a wash primer and a catalyst reducer (which are both very high in VOC content) to apply a coating to the parts so that the paint will adhere well to the surface. This cleaning/phosphating solution would apply a coating of iron phosphate that would do the same thing as the wash primer. Following this conversation I contacted representatives from Oakite and Hubbard Hall who provided me with some more information. I was able to visit Rapid Finishing with Art Berner, president of A.J. Associates who represent Oakite. They have a cleaning/phosphating process at Rapid Finishing that is very similar to the one that would be used at Spraytek. They provided me with some input on how the process has worked for them and allowed me to try the system out on one of Spraytek's parts. I tested this part using only the wash and rinse steps and skipped the final sealant dip. I did this to see if the sealant was actually needed for Spraytek because some companies have been able to make the process work for them without the sealant (the sealant is used to prevent rusting). At first the results seemed good. The part was clean and you could see a blue coating of iron phosphate on the part but before we made it back to Spraytek the part started rusting. I visited Rapid Finishing a second time the following week and tested the process on a second part, this time using the sealant. The results from this test were good. The part was clean, the coating was visible and the part didn't rust. From these two visits I learned that a sealant would definitely be needed for Spraytek to use this process al well as some things about how the process would work and what would need to be done to maintain the process.

During this time I had also been contacting companies to get information about rinse tanks and parts dryers for use in an aqueous cleaning process. I was also working on determining what alterations would need to be made to the degreaser if it was to be used with an aqueous cleaner. This included designing an apparatus that would use compressed air to keep the rinse tank agitated and an apparatus to spray the parts in the wash tank. This spray apparatus would spray the parts as they were being lowered into the cleaning tank to increase the cleaning effectiveness as well as utilize the full space that is available inside the degreaser tank. Another thing I worked on was determining what Spraytek's options were for dealing with the waste water if they found that a large volume was being generated once the system was running.