This kind of exposure is called caustic exposure.
Explanation:
A caustic exposure is an exposure to chemicals present in common household cleaning products like detergents, cleaning solutions, drain cleaners etc.
These contain caustic substances (strong concentration of acid or base) like sodium hydroxide, sulfuric acid etc. When exposed directly on to the skin, due to its stronger concentration, it may burn the skin causing redness, irritation, numbness, or blackening of the skin surface.
Most of the times, these marks go away after some weeks because they are superficial or first-degree burn where only the epidermal layer of the skin gets affected.
