Requirements for emergency shower equipment
What is the minimum flow rate for emergency safety shower and eye/facewash equipment?
Responding is Tim Hartung, industrial product and sales manager, ThermOmegaTech Inc., Warminster, PA.
Emergency safety shower and eye/facewash stations are vital to ensuring worker safety in any industrial facility where employees may come into contact with potentially hazardous chemicals, debris or other materials.
To facilitate compliance, OSHA and the American National Standards Institute detail their recommendations for emergency safety station capabilities and operation. OSHA’s 29 CFR 1910.151(c) states that, “Where the eyes or body of any person may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing of the eyes and body shall be provided within the work area for immediate emergency use.”
The ANSI Z358.1-2014 standard recommendations are more specific in regard to station capabilities, detailing the flow requirement for safety showers as “a minimum of 20 [gallons per minute] at 30 [pounds per square inch],” the flow requirement for eyewash stations as “a minimum of 0.4 gpm at 30 psi,” and combination eye/facewash required flow as “a minimum of 3.0 gpm at 30 psi.” The standard also states that all emergency station outputs should provide an uninterrupted flow of tepid water for at least 15 minutes, even when the shower and eye/facewash in a combination station are activated simultaneously.
Installing a safety shower or eye/facewash station that does not meet these flow requirements poses an additional hazard to workers. Flow rates below the minimum gallons per minute for each output are insufficient for removing the hazardous materials from the user’s eyes, skin, limbs or other body part, potentially leading to an exacerbated injury or chemical reaction resulting from continued exposure to the irritant.
To ensure an emergency fixture is able to meet the minimum-flow requirements as detailed by ANSI’s Z358.1-2014 standard, it’s important to consider plumbing line size, water quality and the tepid water delivery system being used.
Emergency fixtures should be plumbed with an appropriate line size that can provide adequate flow, as well as in consideration of line size compatibility with the station’s inlets. In both cases, a pipe with too small of a diameter won’t provide adequate flow, rendering your emergency fixture in violation of enforced safety standards.
Water quality is often a forgotten factor in emergency fixture installation. It’s important to evaluate whether the water supply from the fixture is free of any sediment buildup that may clog pipes, as well as bacteria that may develop in stagnant water and potentially cause illness to the shower user. The ANSI Z358.1-2014 standard requires that the water supplied to showers and eye/facewashes be potable or safe to drink. Many shower manufacturers offer inline strainers to prevent debris and other contaminants from clogging the eye/facewash spray outlets.
Arguably, the most important factor when implementing an emergency fixture is the tepid water delivery system supplying it. Put simply, an emergency safety station’s flow is dependent on and only as good as the delivery system it draws from. When evaluating thermostatic mixing valves on steam-fired or electrically heated tepid water delivery systems, confirm that your available water pressure and flow is sufficient for both the requirements of the tepid water delivery system and the emergency safety stations.
ANSI recommends testing all safety shower and eye/facewash stations each week to ensure proper working conditions, confirm adequate water supply, and flush any accumulating sediment or bacteria from the system.