Preventing Deaths in Manure Storage Facilities Through Proper Ventilation

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 remove dangerous concentrations of harmful gases and replenish oxygen to levels that will allow them and others to enter storage facilities safely. The standard specifies ventilation times of five, and in some cases, up to more than 15 minutes to remove the contaminant gases and replenish oxygen in the manure pits.

To facilitate the adoption of this standard into new and existing storages, NEC researchers are working on a web-based tool for engineers and agricultural facilities planners. This tool will allow engineers and planners to custom-design ventilation systems for a wide range of new or existing on-farm confined-space manure storage configurations, ventilation system details, and initial contaminant gas levels. The tool will be tested in fall and winter 2013-2014 and is planned for release to the public in spring 2014. For additional information about the tool and manure pit safety, please visit www.manurepitsafety.psu.edu.

This project represents translation of NIOSH-sponsored research into an approved standard. The current phase of this work aims to further translate research knowledge into user-accessible software that enables users to design manure pit ventilation systems and evaluate their effectiveness.

The primary goal of this project from its inception has been to develop tools that designers, farm planning professionals, regulators, and farmers could use to determine the quantity and duration of ventilation required to remove harmful gases and replenish oxygen in manure pits. Development of the ANSI/ASABE standard S607 is one research-to-practice (r2p) outcome of the work. The educational tools that are subsequently being developed are aimed at informing the farm, design, and regulatory community of the need for ventilation and the availability of the standard for planning ventilation. The current effort’s goal is to enhance the already developed r2p outcomes and make the final product even more useful.

The final r2p challenge is making end-users aware of the need for ventilation and convincing them to try the tools to apply the standard to their farms. What are the most effective approaches for raising awareness and motivating potential end-users to try a tool at least once?

What other prominent agricultural safety and health challenges might be most effectively approached in a similar evidence-based, step-wise fashion with a focus on practical r2p outcomes that can make a true difference on the farm?

September 15-21, 2013 is National Farm Safety and Health Week. This year’s theme is Working Together for Safety in Agriculture. For more information about the week’s events, please visit http://www.necasag.org/.

For more agriculture safety and health information, visit the NIOSH Agriculture Topic Page.

Harvey Manbeck, P.E., Ph.D and Dennis Murphy, Ph.D., CSP

Drs. Manbeck and Murphy are researchers with Penn State University/Northeast Center for Agricultural Safety and Health.

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