Formaldehyde-related textile allergy: an update

Part I of this study explores whether clothing today contains formaldehyde levels likely to cause contact allergy in formaldehyde-allergic patients. Part II of this study examines whether current reactions to textiles may be due to allergy to textile resins and whether individuals with formaldehyde-related textile allergy will react to the newer low formaldehyde resins used in the textile industry. Part I: free formaldehyde was measured in 16 fabric specimens produced in the US and overseas. Additionally, since the textile industry has moved to the use of newer methods for measuring fabric formaldehyde content, the newer methodology was compared with the older methods used in the medical literature. Part II: 10 subjects with known textile contact allergy were patch tested to available Chemotechnique textile resins and 6 new low-formaldehyde resins used by the textile industry. Part I: 8 fabric specimens yielded no detectable formaldehyde and 7 specimens yielded <200 ppm free formaldehyde, using Schiff's reagent and Merck testing methods. 1 specimen showed approximately 2000 ppm formaldehyde, as measured by the Merck test, but only 24 ppm free formaldehyde when retested by the method described in Japanese Law #112. Part II: all subjects reacted strongly to formaldehyde and DMDHEU (the predominant resin currently used in textiles). 6 subjects reacted to EUMF. 2 subjects had mild reactions to the newer low-formaldehyde resins and 1 to the non-formaldehyde Fixapret NF. Our results suggest that most clothing today yields free formaldehyde levels unlikely to cause contact allergy in formaldehyde-allergic individuals. Japanese method #112 is the recommended methodology to measure free formaldehyde in future studies. DMDHEU may now represent the main cause of textile allergy and may be a better screen than EUMF for this problem. Newer resins yielding fabrics with <75 ppm free formaldehyde may cause occasional reactions, but are more likely to be tolerated by individuals with textile contact allergy. Treatment of these individuals should be directed at identification of reliable sources of garments utilizing these newer resins.