Toxicity situation
Most anionic and nonionic surfactants are non-toxic, and their LD50 is comparable to that of table salt. However, the toxicity of quaternary ammonium compounds with antibacterial and antifungal effects varies. For example, the LD50 of dialkyldimethylammonium chloride (DDAC, DSDMAC) used as fabric softeners is low (5g/kg) and essentially non-toxic, while the LD50 of the disinfectant alkylbenzyldimethylammonium chloride is 0.35g/kg.
The impact on the skin
Long term exposure to surfactants can irritate and damage the skin, as surfactants can disrupt lipid membranes that protect the skin and other tissues.