Grammar nitpick: “Whom” should only be used for people, possibly animals, and maybe other things in an anthropomorphic context like companies, robots*, etc. Extreme pedants would forbid its use for anything other than actual people.

In this instance, “all of which” would be a better substitute for “all whom” in this instance. In fact, that ought to have been “all of whom” whether “whom” was correct or not.

If you’d said “who” instead of “whom” it might not have awakened my inner pedant, but if you’re going to use “whom”, someone is bound to tell you the proper usage if you make a mistake.

* recyclable or otherwise