Do Your Emergency Showers Meet the ANSI Standard?

The ANSI Standard Z358.1-2009 establishes universal minimum performance and use requirements for emergency eyewash & drench shower equipment used for the treatment of the eyes, face, and/or body of a person who has been exposed to hazardous materials and/or chemicals. First implemented in 1981 theANSI Standard was modified in 1990, 1998, 2004, and most recently in 2009.

Equipment covered by the Standard includes drench showers, eyewash, eye/face wash, portable eyewash, and combination eyewash & drench showers. The ANSI Standard also covers equipment performance and use of personal wash units and drench hoses, which are considered to be supplemental equipment to emergency eyewash and drench shower units.

In addition to performance and use requirements, the ANSI Standard Z358.1 provides requirements for test procedures, employee training, and the maintenance of the equipment.

Most of the ANSI Standard has not changed much since 2004, but the following are the significant changes that were made during the 2009 update:

• Tepid water: The requirements have been moved into the definitions section and are clearly defined with a range of 16°C – 38°C (60°F – 100°F).

• Water Temperature & Tepid Water: Tepid water is crucial, but often overlooked when providing compliant eyewash and drench shower stations. The ANSI Standard specifically mentions the delivery of tepid water and defines it as “A flushing fluid temperature conducive to promoting a minimum 15 minute irrigation period, the suitable temperature range is 16°C – 38°C (60°F – 100°F)”.

Medical professionals recommend that tepid water be used to treat chemically injuries to eyes and body tissue because temperatures that exceed 38°C (100°F) can enhance chemical interaction with the eyes and skin. Additionally, flushing liquid temperatures below 16°C (60°F) can cause hypothermic shock. The standard further states that while cooler flushing fluids may provide immediate relief after chemical contact, prolonged exposure to cold fluids affect the ability to maintain adequate body temperature and can result in the premature cessation of first aid treatment.

Tepid water can be delivered to emergency eyewash and showers in different ways, the most common is to install a thermostatic mixing valve or water tempering valve to blend hot and cold water and provide a temperature within the range defined. These valves should include a hot water shut-off to prevent accidental scalding, and a cold-water bypass to ensure the delivery of flushing liquids in the event that the hot water supply fails. It’s also important to note that standard water mixing valves should not be used.

Most facilities located in the UK have outside temperatures that can drop to below 0°C (32°F) during the winter, therefore emergency stations that can be exposed to freezing temperatures need protection, the standards state that “Where the possibility of freezing conditions exists, equipment shall be protected from freezing or freeze-protected equipment shall be installed”. Conversely locations where the ambient water temperature can exceed 37°C (98.6°F) will require anti-scald valves to purge potentially scalding water from the feed lines. This will include outdoor locations that are exposed to direct sunlight, or indoor locations exposed to extremes of temperature created by a manufacturing process.

• Simultaneous Operation: Units which combine a drench shower with an eye/eye face wash must be capable of being used simultaneously.

• Equipment Location: All emergency stations must be located in areas that are accessible within 10 seconds, roughly 17m (55ft) this is referred to by the industry as the “10 second rule”. Best practice is to check the travel time to determine if you have the emergency station located within 10 seconds, keeping in mind that an injured person may require extra time/support to reach the designated station. Where highly corrosive chemicals are used, thought should be given to installing the emergency station as close as possible to the potential hazard. Remember to check the routing of any electrical supply which might then be within the contamination zone.

• Obstructions: Emergency stations must be located on the same level as the hazard and the pathway between them must be clear of any obstruction. If your site has a hazard that is located on a different level to your current emergency station, you will have to install an additional station on the same level as the hazard. Again there must be no obstructions between them. Please note that a door is classed as an obstruction, but if the hazard is non-corrosive, one door is acceptable between the hazard and the emergency station so long as it opens in the direction of travel of the person requiring its use.

• Identification: Eyewash and drench shower stations must be installed in a well-lit area and identified with a highly visible safety signs.

• Supply Lines: All water supply lines must be provided to meet minimum flow requirements at 30-90 psi. The recommended incoming pipe sizes are as follows:
• ½” for eyewash stations and eye/face wash stations
• 1” for drench showers
• 1¼” for combination eyewash drench showers

• Shut-Off Valves: If shut-off valves are installed on the supply line for maintenance purposes, provisions must be made to prevent an unauthorised shut-off to ensure valves are always open.

• Waste Disposal: Proper disposal of the contaminated water must be considered when installing new equipment. Drainage, freezing temperatures and pollutants, should be considered. We recommend that you consult your Local Authority, Water provider or Environment Agency for additional guidance on the correct wastewater disposal method for your site.

• Training: All employees who may be exposed to hazardous or corrosive materials must know the locations of, and be instructed in the proper use of the eyewash and/or drench shower equipment on site and in addition site plans showing the exact locations of all emergency stations should be freely available to anyone entering the site.

• Maintenance & Testing: Planned maintenance is necessary to ensure that all emergency equipment is functioning safely and correctly. Weekly testing will ensure the supply lines are clear of sediment and bacteria build-up that can occur in stagnant water. The standards state that plumbed equipment, “shall be activated weekly for a period long enough to verify operation and ensure that flushing fluid is available” and portable and self contained equipment “be visually checked to determine if flushing fluid needs to be changed or supplemented”.

• Personal Wash Units/Bottled Eyewash: Bottled eyewash and/or other personal wash units such as single head drench hoses are considered to be supplemental equipment only. These types of units do not meet the ANSI Standard requirements (“A personal wash unit may be kept in the immediate vicinity of employees working in a potentially hazardous area. The main purpose of these units is to supply immediate flushing. With this accomplished, the injured individual should then proceed to a plumbed or self contained eyewash and flush the eyes for the required 15-minute period”) and should not be used as an alternative to a 15 minute emergency flushing station.

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