Despite years of calling on industry to reveal the chemicals used in fracking, companies are disclosing less information about their drilling concoctions through a database set up to aid transparency.

The dataset FracFocus was launched in 2011 to allow oil and gas companies to show what goes into their fracking mixtures. FracFocus, begun as a site where drillers could voluntarily disclose information on their fracking compounds, is the nation’s largest source on chemicals used in hydraulic fracturing. Eventually, more than 20 states made it mandatory for companies to disclose their chemicals to FracFocus.

But over the past two years, frackers have been less forthcoming, according to InsideClimate News, which reported that drillers increasingly cite use of proprietary compounds to limit disclosure.

The trend was discovered by two Harvard University researchers who examined more than 96,000 disclosure forms filed between March 2011 and April 2015. Kate Konschnik, director of Harvard Law School’s Environmental Policy Initiative, said she had expected to find a “growing comfort level” among companies for disclosing chemicals as more states adopted FracFocus as a regulatory portal.

Instead, drillers held back more information. The study found a 16.5% withholding rate on forms filed between 2013 and April 2015, compared to 11% in an Environmental Protection Agency analysis between 2011 and 2013.

-Noel Brinkerhoff

To Learn More:

What Chemicals Are Used in Fracking? Industry Discloses Less and Less (by Lisa Song, Inside Climate News)

Fracking Companies Have Been Getting Worse About Disclosing the Chemicals They Use (by Natasha Geiling, ThinkProgress)

Secrecy over Fracking Chemicals Clouds Environmental Risks, Advocates Say (by Rose Hackman, The Guardian)

Legal Settlement Delivers Blow to Blanket of Secrecy over Fracking Chemicals in Wyoming (by Noel Brinkerhoff, AllGov)

Fracking Industry Wins Weak Ingredient Disclosure Rule (by Noel Brinkerhoff, AllGov)

Fracking Companies Use “Trade Secret” Loophole to Avoid Chemical Disclosures (by Noel Brinkerhoff and David Wallechinsky, AllGov)