Consumer Safety and Aliphatic Diisocyanates
The business of chemistry touches more than 96 percent of the products that we all use every day and accounts for thousands of new products and innovations each year. For example, products made using aliphatic diisocyanates (ADI) chemistry, such as durable cured coatings that protect automobiles, commercial/industrial equipment, aircraft, and bridges—contribute to the safety of modern conveniences.
How Are Consumers Protected from Potential Exposures to Aliphatic Diisocyanates?
The vast majority of aliphatic diisocyanates (ADIs) manufactured are for industrial and commercial use. Aliphatic diisocyanates are known to cause respiratory sensitization at airborne concentrations above the allowable workplace limits; however, exposure to such airborne concentrations is highly unlikely during the use of consumer products.
Consumer products containing uncured aliphatic diisocyanates are very limited (i.e., certain coatings) and are accompanied by product safety information such as warning labels, the characteristics of the chemicals, their approximate cure time, and how to properly protect yourself while handling the product. Thus, overall consumer exposures to unreacted ADIs are expected to be of very low magnitude and frequency.
How Does "Curing" Take Place During Formation of a Polyurethane Product That Uses ADI?
This can be explained by looking at how aliphatic diisocyanates are among the building blocks used to make many polyurethane (PU)-based products, such as coatings, sealants and adhesives. Curing refers to the reaction that occurs between the two primary chemicals used to form a PU product. These primary chemicals are commonly referred to as an aliphatic diisocyanate and a polyol. The aliphatic diisocyanate material is highly reactive and curing begins immediately upon mixing with the polyol material. The cure time varies depending on the type of polyurethane product being produced, the ingredient formulations and other factors in the manufacturing process. Many PU products are completely cured and therefore considered “inert” before they are sold. This means that the original reactive ingredients, the aliphatic diisocyanates and the polyols, in the fully cured polyurethane product are no longer present in their original form. As a result of the reaction, they were transformed during production into the finished product.
The U.S. Environmental Protection Agency (EPA) states that “[c]ompletely cured products are fully reacted and therefore are considered to be inert and non-toxic.” 1
For more answers to questions about aliphatic diisocyanates, visit the Fast Facts and Frequently Asked Questions section.