Residual Bactericidal Action of Wool Blankets Laundered with Formaldehyde: A Hospital Trial

Summary. A hospital trial of wool blankets laundered with a 0·38% (w/v) solution of formaldehyde in the last but one rinse showed evidence of residual bactericidal action of the blankets. On removal from the beds after a fortnight's use, dirty treated blankets contained down to one tenth of the number of bacteria present on dirty untreated blankets. There were also fewer dirty treated than control blankets on which coagulase positive bacteria could be detected. Chemical tests showed that the formaldehyde content of the blankets built up to c. 1%. No complaints were received of odour from the blankets.