The bottle is HDPE (High-Density Polyethylene), which resists acid. But the cap is often polypropylene. If you shake the bottle or it tips over, the acid eats the seal. You will find a puddle of highly corrosive liquid on your floor eating through your linoleum. The Golden Rule: NEVER use it if you have PVC This is non-negotiable.
Instant chemical burn. The dehydration reaction literally chars your skin black. It is painful and scarring. What happens on eyes: Potential blindness in seconds. What happens to your lungs: If you inhale the vapor (aerosolized sulfuric acid), it burns your trachea and causes pulmonary edema. sulfuric acid drain cleaner
While modern schedule 40 PVC is resistant to acid, the heat generated is the killer. If the clog is 4 feet down the pipe, the acid reaction generates enough heat to soften PVC to the point of sagging or collapsing. Furthermore, if the acid sits in the trap for an hour, it can leach the plasticizers out of the pipe, making it brittle. You will find a puddle of highly corrosive