MAPEI has written an open letter to the floor covering industry clarifying the company's position on polyurethane adhesives containing methylene diphenyl diisocyanate (MDI). The letter is published in full below:

An Open Letter to the Floor Covering Industry Regarding MAPEI’s Position on the Subject of Polyurethane Adhesives Containing MDI

Approximately one year ago (April 2011), the U.S. Environmental Protection Agency (EPA) issued a document titled “Methylene Diphenyl Diisocyanate (MDI) and Related Compounds Action Plan [RIN 2070-ZA15]” (Action Plan).

The EPA’s Action Plan states:

“. . . it is important to focus on the safe use of existing polyurethane products through hazard communication and educating product users.”  

MAPEI agrees with the EPA’s focus. We have prepared this communication to provide the following information about the EPA’s Action Plan in order to increase the public’s knowledge on this subject.

FACT 1: There is an EPA Action Plan titled “Methylene Diphenyl Diisocyanate (MDI) and Related Compounds Action Plan [RIN 2070-ZA15],” which was released in April 2011.

The EPA’s Action Plan focused on studying the potential health effects that may result from exposure while using products containing uncured (unreacted) MDI. The Action Plan does not constitute a final EPA determination, nor does it represent any other final EPA action.

FACT 2: The EPA has not imposed a ban on MDI-based materials.

No mandatory requirements of any kind were imposed upon manufacturers of polyurethane products as part of the Action Plan.

FACT 3: The toxicology of MDI and pre-polymerized MDI are extremely well known and regulated within the industry.

MAPEI products are consistently manufactured to the highest safety standards known to the industry, and our product containers are properly labeled in accordance with applicable law.  

FACT 4: While MAPEI lists MDI on the respective Material Safety Data Sheets (MSDSs) of its applicable adhesives, the amount of free MDI actually contained in the formulations is extremely small.

MAPEI’s wood adhesives are very high molecular weight polymers that are made from MDI and other ingredients. Only traces of the original ingredients remain after our carefully controlled polymerization process. Any remaining trace level of MDI is fully dissolved in the adhesive and is not present at a level or concentration that can create a human health risk when used according to our product instructions.

FACT 5: MAPEI is a global manufacturer of many products used in the construction industry, including polyurethane products.

MAPEI recently encountered a similar situation in the European Union (EU) in which urethanes and MDI/TDI-based materials were reviewed by REACH. (REACH is the European Community Regulation on Chemicals and Their Safe Use [EC 1907/2006]. This organization deals with the Registration, Evaluation, Authorization and Restriction of Chemical Substances).

The end result of the REACH review effort was an amendment to REACH in 2010, such that all consumer products manufactured and imported into the EU containing concentrations of 0.1 percent or more MDI must include in their packaging specific types of protective gloves and additional labeling requirements. MAPEI thinks there is a strong likelihood that the USA will follow the EU with similar policy implementation in the future.

In conclusion, we urge everyone to become more aware of the issues affecting our industry, to separately read the EPA’s Action Plan that can be found,and to directly contact the American Chemistry Council Center for the Polyurethane Industry ( and other professional industry associations for a balanced perspective on this issue. When individuals read and weigh the facts, it promotes clarification and better understanding throughout the industry and between our industry and the public.


Jeffrey B. Johnson
Business Manager, Floor Covering Installation Systems
MAPEI Corporation