What is in your soap?

Synthetic Colors

Synthetic Colors are found in everything from food to hygiene products and generally will be labeled as FD&C or D&C, followed by a color and a number. Some synthetic colors are made from coal tar and might contain heavy metal salts that may leave toxins on the skin, causing skin sensitivity and irritation. Many synthetic pigments are made with azo compounds and are considered non-toxic, even though some have been found to be mutagenic. Several case studies have linked azo pigments with certain cancers and are listed on Proposition 65. Reference: Office of Environmental Health Hazard Assessment (OEHHA)

Azo dyes do not degrade under natural environmental conditions. These compounds tend to bioaccumulate in the environment, and have allergenic, carcinogenic, mutagenic, and teratogenic properties for humans. Removal of azo dyes from effluents is mostly based on physical-chemical methods. These methods are often very costly and limited, as they accumulate concentrated sludge, which also poses a significant secondary disposal problem, or produce toxic end-products. Referenve: Archives of Industrial Hygiene and Toxicology. Volume 62, Issue 1, Pages 91–101

Certain azo dyes can break down under reductive conditions to release any of a group of defined aromatic amines. Consumer goods which contain listed aromatic amines originating from azo dyes were prohibited from manufacture and sale in European Union countries as of September 2003. Some of the aromatic amines are classified as being carcinogenic or potentially carcinogenic to humans. Only those few azo dyes that can release these amines upon reductive cleavage are affected. Reference: European Ban on Certain Azo Dyes