Alcohol, with or without an antiseptic, for preparing the skin before blood collection, to prevent bacteraemia or contamination of blood for transfusion.

When blood is collected from blood donors for transfusion it may become contaminated during collection, storage or transfusion. Blood contamination can cause bacteraemia (the presence of bacteria in the blood), severe illness or even death in the blood recipient. When blood is being taken from donors, the skin on the arm of the donor is one potential source of contamination, so it is usual to cleanse the arm with an antiseptic first, and both one-step and two-step alcohol based regimens are commonly used, however there is uncertainty about which regimen is the most effective for reducing the microbial load (the number of microscopic bacterial organisms) on the donor arm. We looked for studies that compared the use of alcohol alone versus the use of alcohol followed by another antiseptic to clean the arm before the needle is inserted to draw blood, but we did not find any relevant studies. It is currently unclear whether donor skin cleansing with a one-step alcohol based regimen reduces the risk of blood contamination compared with a two-step alcohol based regimen during blood donation.