Yes, you can sue for carbon monoxide poisoning in Maryland when the exposure was caused by someone else’s carelessness: a landlord who ignored a failing furnace, a hotel that did not maintain a boiler, a contractor who vented an appliance badly, or a manufacturer whose heater or generator was defective. The claim is an ordinary Maryland injury claim, and it is proved with medical evidence and an investigation of the source.
Two features make these cases different from most. The blood evidence of exposure fades within hours, so what was tested at the hospital matters a great deal. And the most serious injury, damage to memory, concentration and mood, can appear days or weeks after the person seemed to recover.
The medical evidence has to be captured early
Carbon monoxide attaches to the blood in place of oxygen. A blood test measures how much, but the level drops quickly once the person is breathing fresh air or oxygen. A test taken late can read close to normal even after a serious exposure.
- Ask for the carbon monoxide blood test (carboxyhemoglobin) at the emergency room, and get a copy of the result.
- Keep the fire department and EMS reports. Responders often measure carbon monoxide in the air with meters, and those readings help prove the exposure when the blood level has already fallen.
- Write down the symptoms and who had them. Headache, dizziness, nausea and confusion shared by several people in one building, or improving when they left, is itself evidence.
- Follow up even if you feel better. Some people develop problems with memory, attention, balance or mood days to weeks later. Neuropsychological testing documents that change.
Where the injury is lasting, the claim is built like a brain injury claim, because that is what it is.
Where the carbon monoxide usually comes from
- Furnaces and boilers with cracked heat exchangers, blocked flues or poor venting
- Gas water heaters and dryers installed or vented incorrectly
- Portable generators run indoors, in garages or near windows after a storm
- Vehicles left running in attached garages or parking structures
- Space heaters and fireplaces in poorly ventilated rooms
- Boat engines and generators, where exhaust collects around cabins and swim platforms (see boating claims)
- Hotel and apartment building equipment, where one failure reaches many rooms at once, as in the Ocean City hotel carbon monoxide leak in 2025
Who can be held responsible
The question is who controlled the equipment, and who was supposed to inspect, repair or warn about it:
- Landlords and property managers, for heating systems and appliances they supply, and for alarms in the units they rent
- Hotels and other businesses. Guests are invitees, and a business owes invitees reasonable care, including inspecting for hazards. That covers fuel-burning equipment and its ventilation.
- HVAC and plumbing contractors, for installation, venting and repair work that caused the leak
- Manufacturers, where a heater, generator, appliance or alarm was defective (see product liability claims)
- Gas companies, where a reported problem was not properly answered or equipment on their side failed
A worker poisoned on the job usually has a workers’ compensation claim against the employer, and can bring an ordinary injury claim against anyone other than the employer who contributed, such as the contractor who installed the equipment.
Carbon monoxide alarms, and what a missing one means
Maryland law and several county codes require carbon monoxide alarms in certain homes and rental units, depending on when the building was built and what fuel it uses. Whether an alarm was required where you were exposed is one of the first things we check.
Even where no alarm was required, a missing alarm, a dead battery or a disconnected unit is evidence of how the property was run. Keep the alarm if there was one. Photograph where it was mounted, and do not throw it away when the landlord replaces it.
Protecting the evidence after an exposure
After an incident, gas companies and fire departments often shut off and tag the appliance involved. That record is valuable. The risk comes next, when the owner repairs or replaces the furnace, boiler or heater and the failed part is discarded.
- Ask in writing that the appliance, flue and alarm be kept, not thrown away
- Get the names of the responding fire company and the gas company crew
- Keep repair requests, texts and emails you sent to the landlord or management before the incident
- Photograph the equipment, the vent and any soot or staining around it
Prior complaints are often what prove the owner knew. A tenant who reported headaches, a pilot light that kept going out or a furnace that smelled wrong has usually created the evidence the case needs.
Deadlines
Most Maryland injury lawsuits must be filed within three years of the injury. A death follows the wrongful death rules, and the family may have both a wrongful death claim and a claim through the estate.
Public housing and other government-owned buildings are different: claims against government bodies require written notice, delivered to the right office in the right form, well before a lawsuit is filed.
