Mass. Gen. Laws ch. 21C, § 12

Notwithstanding the provisions of any law to the contrary, any information, record, or particular part thereof, obtained by the department pursuant to the provisions of this chapter, shall, upon request, be kept confidential and not considered to be public record when it is deemed by the commissioner that such information, record, or report relates to secret processes, methods of manufacture, or production or that such information, record, or report if made public would divulge a trade secret. This section shall not prevent disclosure of any information necessary for an enforcement action or to comply with RCRA.