Mass. Gen. Laws ch. 148, § 58: Fire extinguishing systems, issuance of certificates for installation and servicing

Section 58. The board may make such rules and regulations as it deems suitable for the issuance of various types and classes of certificates for the following:

(a) a firm engaged in the business of servicing portable fire extinguishers or installing and servicing fixed fire extinguishing systems; (b) an employee of firms engaged in the business of servicing portable fire extinguishers or installing or servicing fixed fire extinguishing systems who services extinguishers or fixed systems; (c) a firm performing hydrostatic testing of fire extinguishers.

The provisions of this section shall not apply to the following:

(a) the filling or charging of a portable fire extinguisher by the manufacturer prior to its initial sale; (b) the servicing by a firm of its own portable extinguishers or fixed systems by its own personnel specially trained for such servicing; (c) the installation or servicing of water sprinkler systems installed in compliance with the State Building Code; (d) firms engaged in the selling at wholesale or retail of portable fire extinguishers but not engaged in the installation or recharging of them; (e) fire departments recharging portable fire extinguishers as a public service where no charge is made; provided, however, that the member of the fire department is trained in the proper filling and recharging of the fire extinguishers.