Safety and stewardships are two tenets that must be stressed by those involved in the silicone industry.
That was the message of Lisa Perricane, Wacker Chemical Corp. manager of regulatory affairs and product safety, who spoke at the 2014 International Silicone Conference, held May 20-21 in Fairlawn, Ohio.
Perricane made her presentation on behalf of the Silicones Environmental, Health and Safety Center, a trade association that advocates for legislative and regulatory issues on behalf of North American silicone producers. She chairs the SEHSC's regulatory and public affairs committee.
“The primary focus of the advocacy is human health and environmental safety and product stewardship,” SEHSC Executive Director Karluss Thomas said in an email interview.
The organization's mission is to promote the safe use of silicones through product stewardship and environmental, healthy and safety research.
North American silicone producers and importers that are members of the organization are: Dow Corning, Evonik (formerly Degussa), Milliken (formerly SiVance), Momentive (formerly GE Advanced Materials-Silicones), Shin-Etsu Silicones and Wacker.
The Environmental Protection Agency has identified 83 chemicals that are to be evaluated under the Toxic Substances Control Act. The SEHSC, meanwhile, regulates the health and environmental safety impact of several industrial chemicals in this act. The list includes three polymers that have a variety of industrial and consumer applications, according to Thomas: D4 and D5, which are cyclic siloxanes, and L3, a linear siloxane.
The SEHSC collaborated with the EPA to develop a monitoring program for D4 to generate environmental exposure data to inform the evaluation. D5 was determined a lesser priority for assessment as a result of the Canadian D5 Board of Review.
The D4 monitoring will be conducted at municipal and industrial facilities with direct discharges to surface water, Perricane said. The agreement was finalized in the first quarter of this year.
The U.S. monitoring wastewater treatment plant will monitor 10 sites, split evenly between residential and industrial, as part of the agreement.
“The monitoring parameters that were discussed and agreed upon were monitoring of influent and effluent waters into and out of those facilities,” Perricane said. “Sampling of surface water, sampling of bio-solids, sampling of the sediment—and this would all involve two monitoring events, which means that they would be two different seasonal events.”
The monitoring could take place in the spring and then again in the winter because “conditions are different with the amount of chemicals in the water,” she said.
Perricane said the SEHSC wants to examine various scenarios, including biota, or the total collection of organisms of the region.
Silicone companies monitoring on the industrial side will include Wacker in Adrian, Mich.; Dow Corning in Carrollton, Ky.; and Momentive, in Waterford, N.Y.; and Sistersville, W.Va. Aspects being monitored include effluent, surface water, sediment and biota (benthic and two fish). Monitoring again will be done in two separate events.
The agreement addresses U.S. state chemical management activity as well.
“Key states right now that SEHSC is focusing on are Washington and Maine,” Perricane said. “In those states, we're seeking to remove silicones from lists of chemicals of concern.”
D4 and D5 are among those chemicals of concern.
“We are finding that more and more states are adding chemicals to these chemicals of concern lists, or lists of chemicals of concern in regards to children's health,” Perricane said.
She said the SEHSC is working to remove those chemicals from those lists.
Canada regulates D4 under a pollution prevention plan developed by Environment Canada. The plan oversees industry physically located in Canada, Perricane said.
The goal is to achieve a total D4 concentration less than or equal to 17.3 micrograms per liter or 3 kilograms per year.
In January 2009, Environment Canada performed a final assessment of D5 and determined D5 was persistent in water and sediment and has toxicity. She said it was not determined whether the regulatory criteria were met due to conflicting laboratory and field data as far as bioaccumulation.
“SEHSC got wind of that, and the ultimate conclusion for D5 at that time was that it was (Canadian Environmental Protection Agency)-toxic,” Perricane said.
“And when something is CEPA-toxic, it ends up being on a CEPA list, and it becomes part of a risk management plan.”
Six months later, SEHSC filed a notice of objection to a proposed order adding D5 to the Schedule 1 of CEPA. After later negotiations and reviews, the matter went to a Board of Review, which determined D5 exceeds the regulatory threshold for persistence and is not toxic to any organism to solubility limits. Thus, D5 does not pose a danger to the environment and projected future uses of D5 will not pose a threat to the environment, according to the board.
Canadian authorities also assessed L3 and found it to be persistent, bioaccummulative and inherently toxic, Perricane said.
“Late last year, SEHSC approached Environment Canada and again, submitted data and wanted Environment Canada to revisit their evaluation and to use more of a risk-based approach,” she said.
Thomas said the SEHSC prefers to use risk-based approaches to assess the safety of chemicals because hazard-based approaches do not typically consider exposure.
Environment Canada did revisit its assessment and ruled it did not meet CEPA-toxic criteria and there would be no further action taken with L3.
Under the Registration, Evaluation, Authorization and Restriction of chemicals, a European Union regulation, D4 and D5 have been deemed to be a hazard. D4 is considered to be toxic, bioaccummulative and persistent, Perricane said, and D5 is persistent and bioaccummulative, but not toxic.
SEHSC has offered feedback on those restrictions, but nothing has been published yet.
“What we're seeing is that the restrictions will be proposed for both D4 and D5 in regard to personal care products,” Perricane said. “And those are products that wash off or down the drain products, such as shampoos and conditioners.”
The silicone industry's stance regarding this is it does weight-of-evidence assessments and results were that D4 and D5 do not need to be regulated in this way, she claimed. “This is all pending draft information in Europe, but the silicone industry is actively involved in the future of silicones and the future of what will be going on with D4 and D5.”