OSHA Emphasizes Hazards of Confined Spaces on Farms

Published January 31, 2018

​A new “Fatal Facts” sheet published by OSHA highlights hazards in the agricultural industry related to working in confined spaces such as grain and feed silos, sump pits, and manure storage tanks. OSHA’s Fatal Facts sheets discuss cases in which employers fail to identify and correct hazardous working conditions, leading to fatalities at their worksites. The new publication describes an incident in which a farm maintenance worker died from asphyxiation after entering a polyethylene storage tank that was not marked to indicate a potential uncontrolled hazardous atmosphere. The worker had been lowered through a 16-inch hole at the top of the tank to fix a broken ball valve inside. The tank contained liquid whey, a substance that produces carbon dioxide gas as it decomposes. The forklift operator had no visual contact or other means to monitor the worker’s progress inside the 12-by-12-foot tank. When he climbed onto an adjacent bin, the operator saw the worker lying face down inside the tank. The fire department responded and cut open the tank to retrieve the worker, who could not be revived.

According to OSHA, the high outdoor temperature and direct sunlight on the tank likely caused the liquid whey to decompose more rapidly than normal, resulting in a hazardous atmosphere. Because the employer had not identified the tank as a hazardous confined space, protective measures were not in place to alert workers and prevent them from entering the tank without recognized controls. 

OSHA urges employers involved in agricultural operations to identify and label all confined spaces to reduce worker exposures to these hazards. Employers should also train workers to never enter a confined space until they are aware of the hazards and steps for safe entry and exit. The agency suggests using a written confined space entry system and developing an emergency action plan to further protect workers. Farm employers should also consider chemical reactions that could occur based on the materials in each confined space as well as potential byproducts that could create a hazardous atmosphere.

For more information, see the Fatal Facts sheet (PDF).