Showers and eyewashes
You have walked past the emergency shower and eyewash every day and you just need to get there now. But where is it? How far away was it? Can you see it? How can you find it? Will it work when you get there? Can I get some help?
The answers to most of these questions should have been determined before the worker was exposed to that terribly nasty hazardous material.
Back to basicsSo, in order to have those answers when you need them, let's go back to the basics. The ANSI Z358.1 standard for Emergency Shower and Eye Wash Equipment is an excellent reference to use as minimum selection criteria for emergency shower and eyewash equipment. The Z358.1 lists, details and describes the dimensions, flow rates and accessories that most North American manufacturers typically use as a compliance target for their product specifications.
Here are six elements of emergency equipment to consider when determining your shower and eyewash safety strategies.
1) Hands-freeStart with the assumption that in most areas where emergency equipment is installed there is potential for worker exposure to hazardous materials that are aggressive and potentially damaging to skin and eye tissue. It is important to understand that any foreign substance that enters the eye will likely cause it to "water" - nature's irrigation process. Even for a particulate, hazard eyewash stations are a necessity at the work site. Peoples' natural tendency is to close their eyes; in this situation they need to hold them open to irrigation, therefore hands-free operation of all equipment becomes necessary.
2) Equipment typesLet's consider the most basic of choices regarding emergency equipment installation. Recommend the use of either plumbed equipment or self-contained stations with sufficient flow per ANSI Z358.1:
3) In the right placeThe placement of emergency equipment can be the most crucial decision made when the treatment of workers exposed to hazardous materials is concerned. Carefully consider the distance and travel time between the identified hazard and the safety appliance.
The first few seconds of exposure to detrimental material can be the most damaging to workers' eyes and skin. Thus, the equipment should be easily accessible but positioned to avoid further contact with the hazardous substance. If necessary, build a barrier between the hazard and the emergency appliance, or locate it away from any spray potential in a well-lit area with proper signage, bringing immediate awareness to the emergency equipment.
Another important element is the space necessary to allow the user to receive assistance from a coworker if necessary. If disrobing was needed to get the substance away from the skin then modesty curtains are a recommended accessory. The installation of an alarm device is advisable to draw attention to the use of the equipment, especially if the user is working alone or in an isolated area. To be effective this device may need to provide local and remote annunciation indicating the use of the emergency equipment.
4) Adequate water supplyThe equipment selection alone will not determine that the injured worker will get the results from the safety appliance as required. Most plumbed eyewash stations deliver more than two gallons of water a minute, and volumes become greater as the other appliances are considered. Eye/face wash stations require three or more gallons, emergency showers a minimum of 20 gallons and a drench hose option can add another three gallons per minute each. The potential simultaneous use of multiple stations will result in cumulative volumes of fluid required.
Determine how many workers are at risk, as the facility utility design must be of a size to support the safety appliance requirements, and install the adequate numbers of emergency stations. Complete the plumbing calculations to determine pipe size for the volume and adequate pressures required to accommodate water flow and ensure that the fluid is available.
5) Not too hotThere is no known study published in a medical or industrial workplace journal or healthcare study to use as a testimonial to identify an acceptable target temperature. It is generally acknowledged that the water should be a "tepid" temperature, defined in the ANSI Z358.1 standard as "moderately warm, lukewarm."
In the Appendix B of that same standard is a recommendation that the water temperature should not exceed 38 degrees C (100 degrees F) for eyewash stations. Many users of temperature-controlled equipment for shower and eyewash stations have specified 80 degrees F to 90 degrees F as the target temperature for years. Consider that the equipment has to be able to deliver water at a usable temperature for the duration of the use of the appliance.
Whatever your choice of an irrigation temperature, you should take caution to ensure that over-heated water never reaches the emergency equipment user. This is especially important when tempered water systems are used in conjunction with eyewashes as the eye tissue is very sensitive to heat and irrigation of the eyes with flushing fluid at an elevated temperature is a high-risk recommendation. Also, make sure that the system has "failsafe" - a design that will prevent the emergency equipment from contributing to an unsafe and potentially harmful condition to the user.
6) What's it made of?Materials of construction are often overlooked as price comparisons can overcome value frequently. Safety equipment must be constructed of a material suitable to the environment and the conditions in which it is to be installed.
Most manufacturers provide materials that will not corrode when exposed to water. If the equipment is exposed to aggressive substances that may deteriorate the components, protective pipe coatings, stainless steel or PVC piped units are more suitable and should be considered. The expense of these materials may initially seem high, but consider your application as it may make long-term functional and financial sense.
The selection of shower and eyewash stations should be carefully completed. While standards can be consulted for minimum requirements, worker needs have to be properly identified relative to the facility and the hazards involved. The safety station placement has to be effective for the worker. This emergency equipment is the last effort in safety and the first step in an injury treatment process.