Oil refinery odors aren’t constant—they typically spike during certain events, often affecting nearby communities. Understanding when they smell and where the impact is greatest can empower residents, regulators, and policymakers.
🟠 When Do Oil Refineries Smell?
Refinery odors are most noticeable during these scenarios:
1. Flaring Events & Upset Releases
Excess gases are burned off due to process disruptions, releasing sulfur compounds like hydrogen sulfide (H₂S) and volatile organic compounds (VOCs).
📍 Example:Martinez, CA — “oily refinery smell” was reported multiple times just before a February fire.
2. Equipment Leaks & Maintenance
Leaks from valves or storage systems often release petrochemical vapors into the air, leading to a solvent-like or gasoline odor.
3. Sour Gas or Wastewater Incidents
When hydrogen sulfide escapes from wastewater treatment or sour gas systems, the result is a distinct rotten-egg odor.
📍 Example:Carson, CA — over 4,700 complaints in October 2021 due to Dominguez Channel releases.
4. Chronic Uncontrolled Emissions
Some older or unregulated refineries emit sulfur and petroleum fumes daily, leading to long-term exposure in fence-line communities.
🔟 U.S. Neighborhoods Most Affected by Refinery Odors
Here’s a list of neighborhoods across the U.S. with frequent complaints about refinery smells and the health and environmental impact:
| Location | Refinery / Source | Community Impact |
|---|---|---|
| 1. Richmond, CA | Chevron Richmond Refinery | Chronic flaring and sulfur smells. |
| 2. Martinez, CA | Martinez Refinery | Odor complaints preceded a 2025 fire. |
| 3. Carson / Wilmington, CA | Dominguez Channel, Phillips 66 | H₂S odor event led to over 4,700 complaints. |
| 4. El Segundo / Manhattan Beach, CA | Chevron El Segundo Refinery | Headaches and nausea from rotten-egg odor. |
| 5. Norco, LA | Shell Norco | Site of historic explosions; residents suffer asthma and headaches. |
| 6. Southwest Detroit, MI (48217) | Marathon Petroleum | Michigan’s most polluted ZIP code. |
| 7. Port Arthur, TX | Motiva Refinery | Benzene and sulfur dioxide exposure. |
| 8. Deer Park, TX | Pemex Refinery | 2024 H₂S leak killed 2, prompted shelter-in-place. |
| 9. Garyville / Lions, LA | Marathon | 2023 toxic fire caused nausea and eye irritation. |
| 10. Commerce City, CO | Suncor Refinery | Asthma, migraines, and cancer risks widely reported. |
You can explore more locations using the interactive Refinery Locations Map.
🧪 What Do These Smells Mean?
Smells are often the first sign of a potentially hazardous release. While not every odor is dangerous at low levels, frequent exposure to compounds like benzene, hydrogen sulfide, or sulfur dioxide may increase the risk of:
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Respiratory issues
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Headaches and migraines
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Fatigue or confusion
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Increased cancer risk (with long-term exposure)
Learn more about what’s in refinery air pollution on the EPA website.
🛠 What’s Being Done About It?
Most modern U.S. refineries must comply with EPA Clean Air Act standards and local air district regulations. Common odor-reducing technologies include:
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Leak Detection and Repair (LDAR)
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Vapor Recovery Units (VRUs)
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Flare gas recovery systems
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Activated carbon scrubbers or oxidizers
Still, enforcement varies by region, and community watchdog groups often report that monitoring is insufficient, especially during emergencies.
📢 What You Can Do
If you live near a refinery, here’s how you can protect yourself and take action:
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Use RefineryMaps.com to locate refineries near you
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Report odor complaints to your local air quality district
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Sign up for text/email alerts from agencies like AirNow.gov
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Join local advocacy groups (e.g., Richmond Our Power, Concerned Citizens of Norco)
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Document and photograph odor events for potential legal use
Final Thoughts
Oil refineries are essential to modern life—but the odors they emit are more than a nuisance. They signal deeper issues with pollution, environmental justice, and regulatory enforcement. Staying informed and using tools like RefineryMaps can help you track risks and protect your health.