Honorable Robert S. Walker
House of Representatives
Washington, D.C.  20515

Dear Mr. Walker:

Thank you for your letter of May 1, 1986, on behalf of your constituent, concerning his questions pertaining to three chemicals which he uses in his trade as a painting contractor. Specifically, he requests information on any federal regulations relating to the disposal, sewage treatment, and neutralization of methylene chloride, muriatric acid, and isocyanates, as well as information on an health hazards associated with their use.

We are reading the first two chemicals in your letter to be methylene chloride and muriatic acid.  Methylene chloride is used as a solvent and is a listed hazardous waste -- EPA Hazardous Waste No. F002.  The listing includes the following spent halogenated solvents:  tetrachloroethylene, methylene chloride, trichloroethylene, 1,1,1,-trichlorothene, 1,1,2-tri-chloroethane, chlorobenzene, 1,1,2-trichloro-1,2,2-trifluoroethane,
ortho-dichlorobenzene, and trichlorofluoromethane.  Unused methylene chloride that is discarded is also defined as a hazardous waste. Muriatic acid is also likely classified as a hazardous waste based on its corrosivity (i.e., it likely has a pH less than 2). The third chemical, isocyanates, is a class of chemicals; thus, before we can respond to your request, we would need to know specifically which compound or compounds your constituent is using in order to address his concerns.

If your constituent generates more than 100 kilograms (220 pounds) of methylene chloride, muriatic acid, or any other hazardous waste in a calendar month at his place of work or at individual work sites, he is classified as a hazardous waste generator and thereby subject to the hazardous waste regulations.  New regulations were just promulgated for generators of between 100 kilograms and 1000 kilograms per calendar month of hazardous waste.  (See enclosed brochure and Federal Register notice.  These requirements become effective on  September 22,  1986.)  If your constituent generates less than 100 kilograms of waste in a calendar month, good disposal practice would dictate that he use an off-site hazardous waste storage, treatment, or disposal facility for his waste, although he may legally dispose of such waste at any state approved solid waste facility.
Your constituent should contact the organization at the address listed below for additional information pertaining to small quantity generators.

     Ms. Eleanor W. Winsor, Executive Vice-president
     Pennsylvania Environmental Research Foundation
     Mezzanine--Lewis Tower Building
     225 South 15th Street
     Philadelphia, Pennsylvania 19102
     (215) 735-0966

With respect to the question relating to neutralization of these chemicals, it is our opinion that it is not possible
for your constituent to neutralize methylene chloride at his place of business.  Muriatric acid, however, can be neutralized.

With respect to the potential health hazards associated with methylene chloride and muriatic acid, he should be aware that methylene chloride is a potential carcinogen.  Muriatic acid, on the other hand, while a corrosive chemical is not highly toxic.  For further information on the proper use and storage of these chemicals in the workplace, he should contract the National Institute for Occupational Safety and Health (NIOSH) at the address given below.

     Dr. James Melius
     Mail Stop R12
     Rm 40A Ridge Bldg.
     4676 Columbia Parkway
     Cincinnati Ohio  45226
     (513) 841-4428

I also strongly recommend that your constituent contact the Pennsylvania Department of Environmental Resources at the address listed below to discuss these issues in greater detail. Depending on the specific nature of his business activities, he may be subject to more stringent state regulations pertaining to hazardous waste disposal.

     Pennsylvania Department of Environmental Resources
     Bureau of Solid Waste Management
     P.O. Box 2063
     Harrisburg, Pennsylvania 17120
     (717) 787-6239

Please feel free to write me if you have any further questions.


J. Winston Porter
Assistant Administrator