Not Legal Advice: There are no Massachusetts state laws that regulate the age to purchase a lighter, but for individual towns/cites or retailers, it may be 18.
Under Massachusetts General Laws (Chapter 148, Section 60) it says:
(a) For the purposes of this section, ''novelty lighter'' shall mean a mechanical or electrical device manufactured for the purpose of producing a flame to light cigarettes, cigars or pipes and which, due to the physical or audio features of the device, excluding its capability of producing a flame, would reasonably be expected to cause the lighter to be appealing or attractive to a child under the age of 10 including, but not limited to, lighters that resemble a cartoon character, toy, gun, watch, musical instrument, vehicle, animal, beverage, sporting equipment or that is capable of playing musical notes or displaying flashing lights.
(b) Whoever manufactures, offers for sale, sells, exchanges, gives away, stores or transports any novelty lighter shall be punished by a fine of not less than $500 and not more than $1,000 or by imprisonment for not more than 1 year, or both.
(c) This section shall not apply: (i) to a novelty lighter manufactured before January 1, 2024 and which is considered a collectible item within the collectible trade; (ii) to a disposable or refillable lighter with a logo, label, decal or artwork printed thereon or on heat shrinkable sleeves attached thereto but which does not otherwise resemble a novelty lighter; or (iii) if not intended for sale or use in the commonwealth, to the interstate transportation of a novelty lighter or to the temporary storage of a novelty lighter while in interstate commerce.
Check out safety rules you should be aware of concerning matches and lighters from Gtmetrofire.org.