Is the Pepperblaster legal in MA?  Its OC but it uses some kind of explosive force to push out the OC.  I'm not a huge fan of pepper spray because its very wind driven. I'd like to give it to my daughter that just moved to Boston.
https://www.kimberamerica.com/pepper-blaster

Probably not, as it uses a 209 shotgun primer for propulsion.  There is the added drawback that it looks like a pistol, and that it only contains two shots.

A good pepper foam would offer more utility, not scream 'gun', likely offer better range, likely include UV or visible dye, and is known not to be restricted in Mass any longer.

Sorry that I don't have a definitive answer to your question.

If the Daughter is attending college in Boston, make sure to read the school's rules FIRST. Some schools allow it and others will expel a student and prosecute as a felony (C. 269 S. 10 "other weapons") successfully. A good friend retired as the prosecutor at Boston College and told me that he prosecuted (successfully) a number of students for having OC on campus. This was a while ago and I have no idea what their current policies are.

Also, Mass law only allows possession of OC without any license required if the person is at least 18 years old.

I also don't recommend the pepperblaster, use conventional spray cans of OC only (with a safety to prevent accidental discharge).

Oh, and conventional OC sprays have trainer [inert contents] units available so that one may practice, without contaminating one's home / yard.

The pepperblaster has very good marketing.  There are more practical options.

Thanks