Environmental researchers Mingce Long and Deyong Wu, from Shanghai Jiao Tong University and Hubei University for Nationalities, China, say their fabric uses a coating made from a compound of titanium dioxide, the white material used in white paint, foods and sunscreen lotions.
http://ummid.com/news/2011/December/16.12.2011/cotton_fabric_cleaned.htm
http://ummid.com/news/2011/December/16.12.2011/cotton_fabric_cleaned.htm