On farms, manure storage facilities are used to store animal waste, which can then be used for fertilizer. Farmers or farm workers may need to enter the facilities to repair or maintain equipment, such as pumps and intake hoses. These confined spaces are often oxygen-deficient atmospheres and can contain toxic and/or explosive gases that create a dangerous environment. Deaths most often occur when a person without necessary life support equipment enters an unventilated manure pit and is overcome by toxic gases or a lack of oxygen. Tragically, these incidents sometimes develop into multiple fatalities when other poorly trained and equipped farm personnel attempt to rescue the initial victim and become victims as well. The average annual number of deaths related to entering manure storage facilities more than doubled between 1975-1984 and 1995-2004, from 1.6 deaths per year to 3.5, respectively (Beaver and Field, 2007).

Harvey Manbeck, P.E., Ph.D. and Dennis Murphy, Ph.D., CSP, researchers working with the Northeast Center for Agricultural and Occupational Health in Cooperstown, NY (NEC; one of nine regional NIOSH-supported Centers for Agriculture Disease and Injury Research, Education, and Prevention), introduced a new international engineering standard (ANSI/ASABE S607) “Ventilating Manure Storage to Reduce Entry Risks”, which was accepted and published by the American Society of Agricultural and Biological Engineers (ASABE) in October 2010.

This voluntary standard provides technical specifications for ventilation rates, configurations, and air exchange rates that would reduce the risk of entry in different types of manure storages. Forced ventilation has been shown to be an effective way to lower the concentration of noxious gases to levels safe for human entry into storage facilities. This standard recommends layouts for positive pressure, mechanical ventilation systems for a wide range of confined-space manure storage facilities that should account for approximately 80-85% of facilities currently in use on livestock farms in the United States.

By installing ventilation systems based on this standard, farmers can …Click here to read the rest of this NIOSH Science Blog post

Reference:
Beaver, RL & Field, WE. (2007) Summary of Documented Fatalities in Livestock Manure Storage Handling Facilities—1975-2004. J.Agromedicine 12(2):3-23.