Eight styles of women's shoes are being recalled globally by Clarks after tests found toxins in the products, the British retailer announced Thursday. "Some samples of these shoes identified excessive levels of the chemicals benzidine or dimethoxybenzidine that are found in azo dyes and are restricted in some jurisdictions," Clarks said in a news release. "Prolonged and direct contact with the shoes' upper material can expose the wearer to these chemicals, which are toxic and can cause adverse health effects."  A potentially cancer-causing substance, benzidine is a synthetic chemical that has not been sold in the U.S. since the mid-1970s, according to the National Cancer Institute. The U.S. used large amounts of the chemical in the past for uses such as making dyes for cloth, paper and leather.  The recalled shoes include the Breeze style in the Americas and the Brinkley style elsewhere, in all navy or dark navy-blue colored and introduced for the spring/summer 2022 season, Clarks stat