"What's past is prologue."
The Bard's quote—allowing history to guide the future—seems apt for a lasting tempest of a different sort, the renewal of a dispute involving the curative agent MOCA, the Polyurethane Manufacturers Association and the U.S. EPA.
The PMA presented its case May 1 to EPA to have the chemical's aggregate point total under the Toxic Substances Control Act lowered by (at least) one, essentially removing MOCA from the risk assessment process by making it low priority.
The curing agent, deemed a "known human carcinogen" by OSHA in 1973, typically is used in dynamic PU components, improving processing and allowing for variations in hardness for products in the oil and gas industry, and the wheel caster and roller spaces.
There is no one-for-one, drop-in replacement for MOCA.
And for more than five decades, there has been a difference of opinion on the science behind the chemical's listing.
The PMA was formed in the early 1970s, coalescing around opposition to OSHA's 1973 decision.
Legal battles followed through the decades, many of them won by the PMA, which established its own guidelines and exposure regulations for MOCA.