Mass. Gen. Laws ch. 94 § 35
Each inspector of milk shall enforce in his town the laws as to the milk supply, and shall make complaint for a violation of any provision of sections nineteen to twenty-eight, inclusive, thirty-three, thirty-eight to forty, inclusive, and forty-one A, upon the information of any person laying before him satisfactory evidence whereby to sustain such complaint. He shall keep an office and shall record, in books kept for the purpose, the name and place of business of each person engaged in the sale of milk within such town. Each inspector of milk or collector of samples of milk may enter each place where milk is produced, stored or kept for sale and each vehicle used for its conveyance, and take therefrom samples for analysis. Upon request made when any sample is taken, he shall seal and deliver to the owner or person from whose possession the milk is taken a portion of each sample, and a receipt therefor shall be given to him. Each inspector of milk shall cause each sample to be analyzed or otherwise satisfactorily tested, and shall record and preserve as evidence the results thereof; but no evidence of the result of such analysis or test shall be received if such inspector or collector refuses or neglects to seal and deliver, upon request as above provided, a portion of such sample to the owner or person from whose possession it is taken. This section shall not apply to milk in the course of interstate commerce.
Mass. Gen. Laws ch. 94, § 35