Breakthrough Clean Technologies, Copper Remover, Solvent, 15ml, 35ct Bowl California Prop 65 WARNING. These products contain a chemical known to the state of California to cause cancer, birth defects and other reproductive harm. Lead: Cas-No. 7439-92-1 Quickly breaks down copper fouling and minimizes future copper build-up 100% ammonia free-User safe and eco-friendly Safe on bore steel-Won't etch or harm barrels Virtually odorless and is biodegradable and petroleum-free Made in the USA Product Description Breakthrough Clean's Copper Remover safely and effectively removes copper fouling and is 100% petroleum and ammonia free. It's virtually odorless and biodegradable formula easily removes copper fouling and minimizes future copper build up without giving off any harmful or strong offensive odors found in other copper removers. Usable on all types of bore steel and won't etch or harm the barrel.