Indoor carbon monoxide exposures in a retail occupancy

Area of Science:

• Occupational Health
• Environmental Health
• Public Health

Background:

• Employees in a retail mall experienced symptoms like headaches and unease.
• An employee reported symptoms, leading to a 9-1-1 call and subsequent fire department response.
• The fire department detected carbon monoxide (CO) in the affected store, prompting an evacuation.

Purpose of the Study:

• To investigate the cause of a carbon monoxide poisoning incident in a retail mall.
• To identify the source and pathway of carbon monoxide migration.
• To propose preventative strategies for similar future incidents.

Main Methods:

• Investigated an incident of CO poisoning in a two-story retail mall.
• Identified the use of liquefied petroleum gas (LPG)-fueled welders during indoor construction as the source.
• Traced CO migration through unsealed floor penetrations into an adjacent store.

Main Results:

• Thirteen employees were treated for CO poisoning on the day of the incident.
• An additional four employees sought medical attention in the following days.
• CO originated from LPG welders on the first floor and entered the second-floor store via floor penetrations.

Conclusions:

• Unsealed floor penetrations allowed CO from LPG welding to migrate between stores.
• Proper sealing of floor penetrations is crucial to prevent CO exposure during indoor construction.
• Implementing stricter safety protocols for indoor construction involving fuel-burning equipment is recommended.