Katherine O’Brien

Deputy Managing Attorney

Toxic Exposure & Health Program

Katherine O'Brien, deputy managing attorney of Earthjustice's Toxic Exposure and Health program, is smiling, looking at the camera.

Bar Admissions

ME, MT (inactive), CA (inactive)

Katherine O’Brien

Deputy Managing Attorney Toxic Exposure & Health Program

Tylar Greene
Public Affairs and Communications Strategist
tgreene@earthjustice.org

Katherine O’Brien is the deputy managing attorney of Earthjustice’s Toxic Exposure and Health Program. Katherine engages in litigation and regulatory advocacy to protect people and wildlife from dangerous exposures to petrochemicals, PFAS, and other toxic chemicals.

Before joining the Toxic Exposure and Health Program, Katherine was an attorney in Earthjustice’s Northern Rockies Office.

Katherine graduated with honors from the University of Washington School of Law, where she was a Gates Public Service Law Scholar and Editor-in-Chief of the Washington Law Review. Before joining Earthjustice in 2013, Katherine clerked for Judge Sidney Thomas on the U.S. Court of Appeals for the Ninth Circuit.

Expert Posts & Articles

Granite Lake, Cabinet Mountain Wilderness
July 17, 2015

Massive Mine Could Destroy One of the Last Best Places for Bull Trout and Grizzly Bears

A major mine proposal in the heart of the Cabinet Mountains Wilderness threatens to destroy one of the last remaining blocks of undeveloped habitat for bull trout and grizzly bears.

Tylar Greene
Public Affairs and Communications Strategist
tgreene@earthjustice.org

Bar Admissions

ME, MT (inactive), CA (inactive)

Quoted in the News

March 13, 2025

The Cool Down

New report finds health threat lurking in countless household products: ‘Unreasonable risk’

"Despite calculating very high cancer risks for people in their homes and also fence-line community residents, EPA has completely written off those risks, and set the stage for no regulation to address those risks. That's deeply disappointing and very hard to comprehend."
January 3, 2025

ProPublica

EPA Report Finds That Formaldehyde Presents an “Unreasonable Risk” to Public Health

“Despite calculating very high cancer risks for people in their homes and also fence line community residents, EPA has completely written off those risks, and set the stage for no regulation to address those risks. That’s deeply disappointing and very hard to comprehend.”
September 30, 2024

ProPublica

EPA Says It Plans to Withdraw Approval for Chevron’s Plastic-Based Fuels That Are Likely to Cause Cancer

“I would say it’s a victory with vigilance required. We are certainly keeping an eye out for a new decision that would reapprove any of these chemicals.”
November 7, 2022

Bangor Daily News

Maine gives companies more time to disclose PFAS use after requests from lobbying groups

“The key concern with the department granting blanket extensions to many or all members of a trade association is whether it is making the required finding that each and every one of those companies qualifies for an extension.”
December 7, 2021

The Intercept

These Chemicals Disrupt the Sexual Development of Children — and They’re Everywhere

“We are very concerned about how EPA is going to identify the fenceline communities and do a lawful and comprehensive risk evaluation without TRI data. The idea that the manufacturers can get in there by requesting a risk evaluation before EPA has the data that really we believe are necessary to support that is very troubling.”

Latest Press Statements

Drinking water is one of the most common routes of exposure to PFAS. PFAS have polluted the tap water of at least 16 million people in 33 states and Puerto Rico, as well as groundwater in at least 38 states.
May 18, 2026

Trump EPA Proposes to Eliminate and Delay Protections from Toxic Forever Chemicals in Drinking Water

The plan would weaken protections for up to 105 million people nationwide
A child fills a drinking glass with water from the faucet.
September 12, 2025

EPA Seeks to Eliminate Critical PFAS Drinking Water Protections

The move continues to expose communities across the country to toxic forever chemicals in tap water
A child fills a drinking glass with water from the faucet.
May 14, 2025

EPA Announces Illegal Plan to Eliminate Restrictions for Toxic PFAS in Drinking Water

Community leaders defending drinking water protections in court denounce Trump administration's capitulation to utility lobbyists and chemical companies at the expense of public health
December 19, 2024

Grupos de Salud Demandan a FDA Para Que Elimine Químicos en Alimentos y Bebidas

Los ftalatos, un grupo de sustancias químicas altamente tóxicas, entran en contacto con productos de consumo mediante empaques o envases, entre otros materiales.
December 19, 2024

Health Advocates Sue FDA to Remove Phthalates from Food

Phthalates leach from packaging and other products into food and drinks
December 12, 2024

EPA Enfrenta Demanda por Laxa Norma Sobre Peligrosas Sustancias Químicas en Electrodomésticos y Muebles

El decaBDE, grupo de sustancias químicas vinculadas al cáncer y a daños en el desarrollo infantil, sigue siendo una amenaza para comunidades indígenas y de primera línea debido a las inadecuadas regulaciones de la agencia federal