Mass. Gen. Laws ch. 94 § 188
The collection of samples under sections one hundred and eighty-six to one hundred and ninety-five, inclusive, and three hundred and four may be made by authorized agents of the department of public health or of boards of health of towns. Samples may be purchased in the open market, and if in bulk and the sample is taken from the original package, carton, wrapper or other container in the presence of such authorized agent, the marks, brands or tags upon such container, and the accompanying printed or written matter shall be noted by such agent, who shall also note the name of the vendor by whom the sale was made, together with the date of the purchase. If practicable, samples shall be collected in duplicate, or divided into two substantially equal parts, and each part shall be labelled with identifying marks. One of such parts or samples shall be delivered to the person from whom they were taken, or, if a guaranty has been given, such part or sample shall be sent to the guarantor. The other part or sample shall be sent to the laboratory of the department or board taking the sample, if said board maintains a laboratory. Parts of samples divided as hereinbefore provided shall be sealed by said agent, at the time of the taking thereof, as provided by the regulations of the department of public health, with a seal provided for that purpose. Whenever it is impracticable either to collect more than one sample or to divide the same, such sample shall be sent to the laboratory of the department or board taking the sample, if said board maintains a laboratory.
Mass. Gen. Laws ch. 94, § 188