The Urethane Blog

ACC Comments on Snurs on Isocyanates

ACC calls for US EPA to withdraw two proposed Snurs

The American Chemistry Council (ACC) has called on the US EPA to withdraw two proposed significant new use rules (Snurs) for certain chemical substances derived from the use of isocyanates as monomers.

The Snurs are for:

  • diisocyanato hexane, homopolymer, alkanoic acid polyalkylene glycol ether with substituted alkane (3:1) reaction products-blocked (generic); and
  • modified diphenylmethane diisocyanate prepolymer with polyol (generic).

The ACC claims in a comment letter the EPA has not made it clear why it issued the proposed Snurs. The trade group’s request for withdrawal is based on its interpretation of a statement the EPA made in the preamble to the proposed rules.

“Despite the limited rationale that is publicly available, it appears that EPA may be basing the proposed Snurs on the hazards and risks of excess and residual monomers rather than on the identified polymers or prepolymers themselves,” the ACC says.

“If it does have such concerns, EPA should indicate why those concerns are sufficient to support the proposed Snurs.”

If the EPA does not withdraw the proposed Snurs, the ACC says the agency should clarify their scope and provisions, and delete their record-keeping provisions.

“EPA should withdraw the proposed Snurs to the extent that they are based on concerns with excess or residual isocyanate monomers,” the ACC writes. “If there has been a shift in agency policy with new isocyanates chemistries, EPA should update the diisocyanates chemical category document to reflect the change and provide adequate justification for any modifications.”

The EPA published direct final rules for these chemical substances on 16 May 2016. However, following receipt of notices of intent to submit adverse comments regarding the final rules, it withdrew them on 14 July 2016. The agency issued the proposed Snurs for the chemical substances on 27 October 2016 and reopened the comment period on 3 January.

The ACC’s diisocyanates and aliphatic diisocyanates panels submitted the comments.