MEMORANDUM

SUBJECT: MIRRO-BRITE Corporations Request for an Applicability Determination Regarding 40 CFR Part 63, Subpart N: Chromium Electroplating and Anodizing NESHAP

FROM: John B. Rasnic, Director

Manufacturing, Energy and Transportation Division

Office of Compliance

TO: Harley Laing, Director

Office of Environmental Stewardship

Region 1

MIRRO-BRITE Corporation requested that the Environmental Protection Agency (EPA) provide a determination as to whether their Potassium Dichromate plating process is regulated under 40 CFR part 63, subpart N: Chromium Electroplating and Anodizing NESHAP. Based on the supplied information, this rule does not apply to the described process. The EPA Office of Air Quality Planning and Standards concurs with this determination. Please note subpart N applies to facilities operating electroplating or anodizing baths and not to suppliers of plating solutions and equipment. Environmental Sciences Services did not indicate the facility and whether the operating parameters are those suggested by the supplier, or those employed by the facility.

The operating parameters of this bath are not typical of either decorative or hard chromium electroplating. The relatively high pH (5.8 to 6.1) of the plating solution and the low current density (40 to 60 amperes applied to a six square foot tank) are both atypical to either a decorative or hard chromium electroplating process. Also, the absence of chromic acid is indicative that this process is not covered by Subpart N. The correspondence from MIRRO-BRITE and its consultant, Environmental Sciences Services, indicates bubbles are observed at the bath surface when the current is applied. The consultant could not account for the bubbles in a subsequent telephone conversation. In the received correspondence, the contractor did not indicate the facility using MIRRO-BRITEs process. In the absence of any in-person observations or in-depth data provided by the company, the state or the Region may require a performance test or other sampling to determine whether this electrochemical process does, in fact, produce chromium mist and may be considered subject to subpart N.

Mirro-BRITE sent this request directly to this office after speaking with the Region. Please note the authority to issue applicability determinations pursuant to 40 CFR part 63 has been delegated to the Region. Hence, in the future, you need not forward these requests unless you need our assistance or the issue is of national significance. If you have any questions, please call Greg Waldrip at 202-564-7024.

cc: Greg Waldrip

Rick Bobrycki, EPA New England