Nev. Rev. Stats. § 202.380 bars felons from possessing "tear gas," defined in § 202.370 as:

all liquid, gaseous or solid substances intended to produce temporary physical discomfort or permanent injury through being vaporized or otherwise dispersed in the air. The term does not include a liquid, gaseous or solid substance whose active ingredient is composed of natural substances or products derived from natural substances which cause no permanent injury through being vaporized or otherwise dispersed in the air.

My question: How exactly should courts interpret the phrase "composed of natural substances or products derived from natural substances" mean here? In a sense, isn't everything composed of products derived from natural substances?