Mobile Scaffold WheelsSewage systems on vessels and shipyards can be silent killers, causing fatal injuries to maritime workers performing repairs and maintenance. Employers and shipowners have a duty to protect employees from known hazards of working at sea, including invisible dangers such as hydrogen sulfide. If you or your family member suffered health effects from toxic gas exposure, you need a Jones Act injury attorney to get you everything you're owed under the law.

Exposure to Hydrogen Sulfide in Sewage Systems Can Be Deadly to Jones Act Workers

Inhalation of hydrogen sulfide (H2S) gas can cause death in a matter of minutes. Also called sewer gas, it’s a common by-product of human waste and smells like rotten eggs. It can collect in a vessel’s sewage tanks, Collection Holding and Transfer (CHT) system, or any pipe or area connected to the waste management system.  

Seamen may lose consciousness in seconds and suffer fatal asphyxiation if the area is not evacuated immediately. When exposure is not fatal, it may result in headaches, poor attention span, memory loss, and impaired motor function after regaining consciousness. Difficulty breathing and cardiovascular problems have also been reported after hydrogen sulfide exposure.

Hydrogen sulfide gas is more likely to cause fatalities when combined with:

Confined spaces

Hydrogen sulfide is heavier than air and can collect in the ship's lower levels, particularly in enclosed, poorly ventilated areas. A worker entering an unsanitized sewage tank could suffer rapid unconsciousness that causes a fall.

High concentrations

Injuries increase with the amount of hydrogen sulfide that enters the space. At low levels, a worker’s eyes, nose, and throat are affected; in moderate concentrations, a worker can suffer severe difficulty breathing, headache, dizziness, nausea, or vomiting. High concentrations can cause an inability to breathe, convulsions, shock, coma, and death within minutes.

Training failures

Employees should be provided with an easy and unobstructed escape path away from any areas containing sewage. A safety watch should be posted at the opening of the space in case a rescue team is needed.

Improper testing

Before anyone may enter an area where hydrogen sulfide could be present, the air must be tested by a qualified person using functional equipment. The person should be able to determine the hydrogen sulfide concentration and whether fire or explosion precautions are necessary. It is NOT sufficient for workers to rely on their sense of smell to detect gas since the odor may be faint or inconsistent.

Ship defects

Employers must ensure that all piping, valves, and back-flow prevention in the sewage system are in good working order. Any corroded or broken piping could allow sewage gases to seep into connected sealed spaces (such as sleeping areas). The site must also be chlorinated or otherwise sanitized to kill potentially infectious waste before employees may enter.

Inadequate PPE

If gas is present but, the space cannot be ventilated, workers should be issued appropriate respiratory protection, rescue gear, and communication equipment. Atmospheres containing H2S concentrations higher than 100 ppm may only be accessed using a self-contained breathing apparatus (SCBA).

Failed evacuation procedures

Employees should be trained to evacuate immediately if liquid begins to enter the space or if they suddenly feel dizzy or sluggish. Once a space has been evacuated, nobody may re-enter until a competent person has retested the atmosphere and determined that the area is safe.

Let Our Maritime Injury Lawyers Ease Your Burden

If you or someone you love was injured by hydrogen sulfide gas while working on a vessel, the experienced maritime attorneys at Hofmann & Schweitzer can review your case and explain your options at no cost. Call us at 1-800-3-MAY-DAY or fill out our online contact form to begin your no-obligation consultation. We also invite you to read our complimentary guide, Are You a Seaman Injured in a Maritime Accident? Know Your Rights.


Paul T. Hofmann
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Focused on personal injury, with an emphasis on maritime, railroad and construction worker tort claims.