Because ammonia is corrosive to the eyes, skin, and lungs, and is inflammable in certain concentrations in the air, it poses a serious health hazard. Despite its risks, it is useful as a refrigerant, and ammonia refrigeration is common in the food-processing and preservation industries. Since it can pose a danger to workers and the environment, the federal government and industries that use ammonia have developed regulations for its safe use.
Process Safety Management
The U.S. Occupational Health and Safety Administration (OSHA) regulates ammonia refrigeration through strict guidelines. Twenty-five states, Puerto Rico, and the Virgin Islands have adopted OSHA-approved state plans as well that are largely identical.
Guidelines for the process safety management apply to systems containing 4536kg. or more of ammonia. The guidelines are highly detailed, and state that employers must conduct a process hazard analysis (PHA), ensure the mechanical integrity of their ammonia processing systems, implement emergency preparedness plans, and ensure that all employees receive training on the risks and safe use and management of ammonia.
Personal Protective Equipment
OSHA also mandates that employers equip all workers who may be exposed to ammonia with personal protective equipment. Equipment shall include protective wear for the eyes, face, head and extremities, as well as respiratory devices and protective shields and barriers. Protective equipment should be kept sanitary and designed to safely and effectively perform work.
Hazardous Waste Removal
Strict OSHA regulations govern safe hazardous waste operations and removal. Employers are required to create and implement a safety and health program for employees, contractors and subcontractors involved in hazardous waste operations that concern chemicals such as ammonia. The program should be designed to control health and safety hazards, as well as provide for emergency response in hazardous waste operations.
Organizations such as the American Society of Mechanical Engineers (ASME) and the International Institute of Ammonia Refrigeration (IIAR) have also developed industry-based standards, independent of the OSHA, to regulate the use of ammonia as a refrigerant. These comprehensive guidelines are available through membership or purchase.
The ASME covers ammonia regulations in its Boiler and Pressure Vessel Code, available for purchase for £442, while the IIAR's guidelines for risk management and process safety management are available in a packaged set for £1,950 to non-IIAR members and £1,300 for members, as of September 2010.