Polymer sector faces fall-out from US silica exposure rule

Washington – A new federal rule aimed at protecting workers from silica exposure will have more significant impact on the polymer sector than some may think.

Under the US Department of Labor’s Occupational Safety and Health Administration rules, permitted exposures to silica in the construction industry would be cut to 50 microgrammes (mg) per cubic meter of air over an eight-hour period from 250mg. In other industries, which have a 100 microgram standard, it will also be reduced to 50mg.

The rules are set to take effect 23 June though the first compliance dates are at least another year away: 23 June, 2017, for construction; 23 June, 2018 for general industry — which would include plastics manufacturing; and 23 June, 2021, for oil and gas fracking operations.

An estimated 2.3 million US workers will be affected by the new rules, with about 2 million of them in construction-related industries, according to the US Labor Department.

While silica exposure gets the most attention in mining and construction, precipitated and fumed silica are used in plastics as fillers, thickeners or softeners and in aiding flow for processing thermoplastics, compounds, composites and thermoplastic elastomers.

Silica also is used as fillers in popular composite countertop materials, such as DuPont’s Zodiaq. And it has been suggested as a replacement for plastic microbeads in cosmetic and personal care products, which have fallen out of favour or been legislated off the market.

The new rules impact “anybody that kicks up respirable silica,” as one expert put it, which could include compounders and resin producers that add silica to plastics. The 600-page rules are much stricter than current 1970s-era rules for personal protective equipment and housekeeping, written exposure control planning and engineering controls such as pricey ventilation systems.

Officials estimate that the new silica standard, when fully in effect, will save more than 600 lives and prevent more than 900 new cases of silicosis, a dangerous and often fatal lung disease, every year. Though OSHA estimates the cost of the rule at about $1 billion annually, the agency expects net benefits of $7.7 billion a year once it is in effect.

Trade groups whose industries will be impacted disagree with OSHA’s estimates.

“Our economists calculated, throughout general industry, the cost would be much, much higher than what OSHA claims,” said Kevin Moran, director of the American Chemistry Council’s Crystalline Silica Panel. “There’s a difference of opinion on what it’s going to cost. And it’s hard to say because there’s so many diverse industries out there, and all the unique and individual companies.”

A small plastics compounder would have to pay the same price for a ventilation system as a big company, Moran said. Such compliance costs will add up throughout the supply chain and eventually be passed down to consumers.

An economic cost-benefit analysis of the new silica rules by Washington-area policy study group Environomics, on behalf of ACC, projects the incremental costs of meeting the new standards to be approximately $4.7 billion per year.

A more economical — and possibly even effective — fix, the study says, would be to better enforce the original rules. Even OSHA agrees that as many as 30 percent of the US companies exposing workers to airborne silica are not complying with the original rules.

While the new rules are, for the most part, a done deal, a parade a lawsuits could prevent them from going into effect, even after a more than 30-year battle to get more stringent rules on the books. Petitions challenging OSHA’s new silica rules have been filed in six federal appeals courts, though the US Labor Department last week asked the courts to consolidate the petitions into a single case.