1,2‐Benzisothiazolin‐3‐one in disposable polyvinyl chloride gloves for medical use

Background: Benzisothiazolinone is used as a slimicide in the manufacture of disposable powder‐free polyvinyl chloride (PVC) gloves. We recently reported 6 patients from dentistry and health care probably sensitized to benzisothiazolinone in PVC gloves. Objective: The study aimed to investigate how widely disposable PVC gloves for medical use on the Finnish market in 2006 contain benzisothiazolinone and to report new cases from 2 clinics in Helsinki. Methods: 31 brands of disposable PVC gloves were analysed for their benzisothiazolinone content. We looked through the patient material of Helsinki University Central Hospital to find benzisothiazolinone allergic patients. We also described 3 previously unpublished benzisothiazolinone allergic patients from Finnish Institute of Occupational Health. Results: 9 (30%) of the 31 glove brands contained 3–26 p.p.m. benzisothiazolinone. From the 2 clinics, we found 5 new benzisothiazolinone allergic patients who had used PVC gloves containing benzisothiazolinone. In addition, 3 patients had used disposable PVC gloves whose benzisothiazolinone content remained unknown. Conclusions: In Finland, benzisothiazolinone in powder‐free PVC gloves has caused a small epidemic of allergic contact dermatitis in dental personnel and other health care workers. 1/3 of the disposable PVC gloves contained some benzisothiazolinone. A concentration of 20 p.p.m. benzisothiazolinone in a glove seems to be enough for sensitization.