When oil spills happen, the industry’s favorite response tool isn’t a mop or a containment boom — it’s a chemical cover-up. Oil dispersants like Corexit 9500A don’t actually clean up oil. They just break it into smaller particles, sinking it out of view. But out of sight doesn’t mean safe. In fact, dispersants mixed with oil can be more toxic than the oil alone — to humans, marine life, and entire ecosystems.
After the Deepwater Horizon blowout in 2010, nearly 2 million gallons of dispersants were dumped into the Gulf of Mexico. Since then, the science has become clear: this chemical “solution” has created lasting damage. Multiple studies show that oil-dispersant mixtures are up to 52 times more toxic than oil alone. The results? Alarming and widespread:
- For humans: Dispersant exposure has been linked to respiratory problems, skin rashes, asthma, cancer, reproductive harm, and long-term organ damage — especially for cleanup workers and coastal residents.
- For marine life: Corexit mixtures disrupt gill function, kill zooplankton, poison sea turtles and seabirds, weaken dolphin immune systems, and inhibit the bacteria that naturally break down oil — making cleanup harder, not easier.
- For ecosystems: These toxic blends persist in the environment, harming coral, contaminating food chains, and disrupting reproduction in species like oysters.
These effects aren’t rare. They’re consistent. And deadly.
In the latest salvo in a legal fight we’ve been involved in for decades, Inletkeeper has filed a noncompliance complaint with OSHA and the EPA, demanding transparency and accountability on the safety hazards posed by dispersants. This recent move continues our work of pushing for clean waters, and protecting the Cook Inlet watershed and the life it sustains.
How did we get here?
In 1989, the night before the Exxon Valdez oil spill in Prince William Sound, Dr. Riki Ott warned the Valdez Chamber of Commerce, “It’s not a matter of if, but when, the big oil spill occurs…” Just hours later, a tanker loaded with 53 million gallons of crude left the terminal — and disaster struck.
As a marine toxicologist and former commercial fisherwoman, Riki witnessed the ecological and social destruction firsthand. She has since dedicated her career to exposing industry lies and advocating for workers harmed by oil and chemical exposure. Through The ALERT Project, she continues to protect communities and first responders from toxic dispersants.
Cook Inletkeeper has been part of this fight for years, alongside Riki Ott, Alaska Community Action on Toxics, and other partners. We advocate for stricter regulations on dispersant use — because these chemicals make oil spills worse, not better.
Out of Sight, Still Deadly: BP’s Deepwater Horizon and the Legacy of Corexit
When BP’s Deepwater Horizon rig exploded in 2010, killing 11 workers and spewing oil into the Gulf, BP scrambled to control the damage. But instead of prioritizing cleanup, they prioritized optics: pumping nearly 2 million gallons of dispersants into the water column to keep the oil from surfacing.
The ecological fallout was devastating. Long after the headlines faded, marine ecosystems, coastal communities, and frontline workers continued to suffer the effects of Corexit exposure.
Science on Our Side: What the Research Shows
Over the past decade, a growing body of peer-reviewed science has confirmed what frontline communities have long known: oil-dispersant mixtures are deadlier than oil alone. Key findings include:
- Dispersant-oil blends impair respiratory, immune, and reproductive systems across species.
- These mixtures increase cancer risk and disrupt endocrine function in humans.
- Corexit 9500A reduces oil biodegradation and kills beneficial oil-degrading bacteria.
- Zooplankton and deep-sea corals show severe toxicity when exposed to dispersed oil.
Learn more in this 2024 Dispersant Fact Sheet
The Long Legal Battle: Forcing the EPA to Act
- 2012: Concerned citizens petition the EPA to update dispersant rules in the National Contingency Plan (NCP).
- 2020: After 8 years of delay, Inletkeeper joins a lawsuit against the EPA. A federal court rules that the agency must revise its outdated rules.
- 2021: The court orders the EPA to update the NCP by 2023 and file status reports every 180 days.
- 2022: The manufacturer of Corexit “voluntarily” withdraws its products rather than face public disclosure of health impacts.
- 2024: The ALERT Project, Earth Island Institute, and the Government Accountability Project petition the EPA to immediately remove Corexit 9527A and 9500A from the list of approved spill response agents.
- 2025: When that petition went unanswered, we filed a noncompliance complaint with OSHA and the EPA, citing violations of the Hazard Communication Standard. Dispersant manufacturers had failed to disclose known human and environmental harms in their safety data sheets — a clear threat to workers and ecosystems alike.
What We’re Fighting For
We are demanding full transparency and accountability on dispersants. These chemical products:
- Cause skin and eye irritation, allergic reactions, and respiratory distress
- Increase risks of cancer, asthma, and reproductive harm
- Damage organs with prolonged exposure
- Are hazardous to aquatic life with long-lasting effects
Despite this, they remain authorized for oil spill response. This toxic legacy is made worse by efforts to expand offshore oil and gas drilling, from the Arctic to the Atlantic. More drilling means more spills. More spills mean more dispersants. And while government agencies resuscitate the oil industry with weak regulations and chemical coverups, frontline workers and marine life are left gasping.
It doesn’t have to be this way.
We can stop using chemical band-aids and start demanding real cleanup, real transparency, and real protection for the people and places we love. While the current administration gives CPR to the unbeating heart of the oil & gas industry, protecting workers, marine life, and coastal residents is more urgent now than ever. Our first responders deserve better, as do their families, our waters and the life it sustains.
Further Reading & Resources
- Judge orders EPA to update rules for dispersants used on oil spills (Alaska Public Media)
- The ALERT Project – Fact Sheets
- Inletkeeper Lawsuit Against Toxic Dispersants
- Toxic Dispersants Resource Page
- EPA Issues Final Rule on Dispersants
- Annie O’Neill Thesis on Exxon Valdez Cleanup
- 2024 Dispersant Fact Sheet (ALERT)
- EPA Delisting Petition (ALERT)