Fatality Assessment and Control Evaluation (FACE) for Michigan: Two Individuals Overcome By Hydrogen Sulfide Gas While Cleaning a Farm Facility Water Well with 28% Liquid Muriatic Acid

摘要

On August 15, 2001, two males, an Amish farmer, 42 years old, and a friend, 60 years old, died from inhalation of hydrogen sulfide gas while cleaning the well screen of a driven point well with 28% uninhibited liquid muriatic acid. The well was approximately 300 feet from the road, was approximately 150 feet west of the residence, and was 20-25 feet downhill from the livestock barn. A 5 feet x 5 feet wood shed was built around the well for protection. The shed was approximately 8 feet tall, had a 30 inches door facing east, had 2 inches x 4 inches studs and had particleboard walls with batt insulation. There were no windows in the shed. The well pit had concrete walls. The pit was approximately 4-1/2 feet deep, was 4 feet x 4 feet wide, and had a 2 inches x 8 inches wood plank across the pit opening. At the base of the pit, there was a driven point well with a 2 inches steel pipe and a jet pump. The emergency responders found an empty 64-ounce container of muriatic acid, a 1/4 full 64-ounce container of muriatic acid, funnel and 1/2 inches white polypropylene plastic tubing nearby. The funnel was outside of the wells protective structure; the tubing was inside of the well. The well casing was open. The well was running 'slow' and the owner thought the problem could be a plugged well screen. The farmer used liquid muriatic acid to clean the screen. The event was unwitnessed, so the actual sequence of events is unknown. There appears to have been a reaction when the muriatic acid was added to the well water, resulting in a hydrogen sulfide emission from the well. A family member of the victim detected the muriatic acid odor and went to investigate. The family member noticed the individuals and went to the house to call emergency personnel. When the emergency responders arrived, the individuals were found in the well pit in approximately 4 inches of water/muriatic acid. Upon arrival at the scene, emergency personnel could detect a muriatic acid odor from the road. One of the individuals succumbed to hydrogen sulfide fumes and died at the scene; the other individual was transported to a local hospital, where he later died.