Skin antisepsis in invasive procedures aims to reduce the bacterial load at the site of incision or puncture. Alcohol solutions seem to be more effective in preventing surgical site infection. From the safety point of view there is the potential risk of ignition when using alcohol solutions. Given the potential neurotoxicity of alcohol and chlorhexidine gluconate, contact of antiseptic solutions with the central nervous system should be avoided. This article is part of a supplement entitled "Antisepsis in the critical patient", which is sponsored by Becton Dickinson.