“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.” This short sentence continuously causes questions among safety personnel. What is immediate? What are suitable? What are the flow requirements? How often should they be tested? This article will seek to answer those questions.
Emergency Shower and Eye Wash Station Requirements
1. Water Quality
• Temperature. The water has to be tepid (Appendix B-6). Temperatures exceeding 38oC have proven to be harmful and may enhance chemical interaction. Cold flushing may help reduce chemical interaction; however, prolonged exposure may effect body temperature in the case of showers. If located in areas subject to freezing, the unit must be protected from freezing.
• Potability. Water used must meet at least drinking water standards.
2. Access. The shower and/or eyewash has to be “immediately available”, which has been interpreted to mean within 10 seconds of unobstructed travel. The new ANSI standard indicates that when using strong acids or bases, the unit should be next to the workstation. The area around the unit should be unobstructed to enable the user to get to it unhindered.
3. Signs. A highly visible sign must mark the unit location. Shower areas have to be well lighted. ANSI recommends that an alarm be attached to warn others that the unit is in operation. Be sure to deactivate the alarms during weekly activation.
4. Water Delivery
• Water capacity. The inlet supply must be at least 30 psi. Normal design levels are usually 45 psi. Pressures over 80 psi are considered excessive and may injury the exposed employee.
• Valve Operation. The valve must activate within 1 second and remain on without being held on. Self-closing valves may be permitted in a school laboratory as a limited option.
5. Testing or fluid replacement.
• Plumbed units are to be activated weekly to flush the line and verify operation1. “Flush” is not defined. However, water testing has shown that pathogenic microorganisms (Acanthamoeba, Pseudomonas and Legionella subspecies) can buildup (2,3). To prevent this, at least a 3-minute flush is recommended (2,4). Units must be tested annually to verify conformance with ANSI requirements.
• Fluid replacement frequency in self-contained units depends on whether a preservative is used.
> Plain water: weekly replacement
> If a preservative is used, 1-4 month replacement depending upon conditions
> If a factory prepared concentrate with an additive
1 Interestingly, the California requirement (8 CCR 5162) is only monthly activation.
is used, then follow the manufacturer’s instructions > If factory-sealed cartridges are used, up to two years may be acceptable. (these units do not need flow testing).
6. Waste Disposal. A shower operating for 15 minutes will deliver between 300 and 450 gallons. If a drain is not present, a considerable volume of water will accumulate. Some facilities have a sump to collect the shower waste to enable the water to be tested before final disposal to ensure that it meets discharge requirements. Sewer odors may develop if the unit is not tested frequently because the water trap is drying out. If weekly activation is performed, water will remain in the trap and eliminate the odors.
7. Training. Employees have to be instructed where the showers/eyewashes, including personal eyewash units and drench hoses, are located and how to use them. For eyewash use, employees have to be instructed to hold their eyelids open and rolling the eyeballs to permit flushing.