A resin used for making non-wrinkle shirts releases formaldehyde, which could cause contact dermatitis for some people; no disclosure requirements exist, and in 2008 the U.S. Government Accountability Office tested formaldehyde in clothing and found that generally the highest levels were in non-wrinkle shirts and pants. In 1999, a study of the effect of washing on the formaldehyde levels found that after 6 months after washing, 7 of 27 shirts had levels in excess of 75 ppm, which is a safe limit for direct skin exposure.
A resin used for making non - wrinkle shirts releases formaldehyde , which could cause contact dermatitis for some people ; no disclosure requirements exist , and in 2008 the U.S. Government Accountability Office tested formaldehyde in clothing and found that generally the highest levels were in non - wrinkle shirts and pants . In 1999 , a study of the effect of washing on the formaldehyde levels found that after 6 months after washing , 7 of 27 shirts had levels in excess of 75 ppm , which is a safe limit for direct skin exposure .
How many months of washing did a 1999 study look at?
How many months of washing did a 1999 study look at ?
6
6