Toxins in Leather
The basic components of leather coatings are binders, lacquers, colouring agents, solvents (organic substances, water) and additives (surface active substances, waxes, oils, cross-linking agents for water-based systems and other chemicals).
Various resin types can be used as binders e.g. acrylics, butadienes, polyurethanes and vinyl acetates. Solvent based resins are used for special effect coatings and to achieve particular requirements (for example, to preserve the appearance of leather which is subject to wet-rubbing and wet flexing or to increase the permeability of the leather). The most commonly used binders are water-based resins (purchased as powder or dissolved in sodium hydroxide and other chemicals).
Lacquers may consist of nitrocellulose dissolved in organic solvents or polyurethane in water-based systems. Colouring agents are organic and inorganic pigments, dissolved in the particular coating systems (water or solvent-based).
CONVENTIONAL SOLVENT-BASED COATINGS CONTAIN:
80 – 90 % VOC (volatile organic compound)
Conventional solvent-based systems contain between 80 – 90 % VOC while reduced organic solvent systems (e.g. water dilatable lacquer emulsions) contain ~40 % VOC.
WATER BASED COATINGS CONTAIN:
0 – 15 % VOC
Water based systems can contain 0 – 15 % organic solvents (e.g. ethyl acetate) but most commonly used water-based lacquers contain 5 – 8 % VOC.