What is MDI?

MDI is the acronym representing methyl diphenyl diisocyantate. There are three main versions of this compound:

• 2,2′-MDI
• 2,4′-MDI
• 4,4′-MDI

The 4,4′ isomer is most widely used.

Who makes MDI

Bayer followed closely by Yantai Wanhua. Other major producers are BASF, BorsodChem, Dow, Huntsman and Nippon Polyurethane Industry. All major producers of MDI are members of the International Isocyanate Institute. Their main purpose is the promotion of the safe handling of MDI and TDI in the workplace, community and environment. This implies that there is an inherent risk or danger involved with the use of this chemical.

How Dangerous is MDI?

MDI is an allergen and sensitizer, meaning that once certain amount of exposure occurs, the person is more susceptible to reaction at much lower concentrations. Persons developing sensitivity to isocyanates may have dangerous systemic reactions to extremely small exposures, including respiratory failure. Handling MDI requires strict engineering controls and personal protective equipment. With this knowledge it must be understood, that even though the resulting chemical reaction of polyols and MDI is a safe rugged durable polyurethane or polyurea coating, the process of applying this material is where the danger lies.

Marketing information for spray bedliner materials and other coatings tends to bypass this important fact. Yes, it’s stated in the msds sheets, or in fine print. However, generally sales people leave out the very important fact that any exposure to mist from the process of spraying a bedliner can result in allergic and sensitized reaction to the components. This is DANGEROUS and should be taken very seriously.

MDI Exposure from Bedliners

We would like to hear from anyone who has had physical negative side effects resulting from the exposure to spray on bedliners or other coatings involving polyurea or polyurea hybrids.

Why Do We Care?

We are manufacturers of high quality polyurethanes and polyhybrids that do not use MDI for reactions. We continue to research polyureas and polyurethane vendors. In that research, we find some covering up the facts about MDI in their products, or at least the danger associated with them.