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Quick Response Essential Importance of Emergency Showers and Eyewash Stations July is eye injury prevention month, so it’s a good time to consider that accidental chemical exposures can still occur even with good engineering controls and safety precautions.The first 10 to 15 seconds after exposing the eye to a hazardous substance, especially a corrosive substance, are critical. Delaying treatment, even for a few seconds, may cause serious injury. Initial treatment can begin with emergency showers and eyewash stations, which provide on-the-spot decontamination and allow workers to flush away hazardous substances that can cause injury. As a result, it is essential to look beyond the use of goggles, face shields, and procedures for using personal protective equipment. Emergency showers and eyewash stations are a necessary backup to minimize the effects of accidental exposure to chemicals. Emergency showers can also be used effectively in extinguishing clothing fires or for flushing contaminants off clothing. For emergency showers and eyewash stations to be effective, the American National Standards Institute (ANSI) Standard for Emergency Eyewash and Shower Equipment (ANSI Z358.1-2004) recommends that the affected body part must be flushed immediately and thoroughly for at least 15 minutes using a large supply of clean fluid under low pressure. Water does not neutralize contaminants — it only dilutes and washes them away. This fact is why large amounts of water are needed. However, other references recommend a minimum 20-minute flushing period if the nature of the contaminant is not known. The flushing or rinsing time can be modified if the identity and properties of the chemical are known. For example: • A minimum five-minute flushing time is recommended for mildly irritating chemicals; • At least 20 minutes for moderate-to severe irritants; • Twenty minutes for non-penetrating corrosives; and • At least 60 minutes for penetrating corrosives. Non-penetrating corrosives are chemicals that react with human tissue to form a protective layer, which limits the extent of damage. Most acids are non-penetrating corrosives. Penetrating corrosives, such as most alkalies, hydrofluoric acid and phenol, enter the skin or eyes deeply. Penetrating corrosives require longer water flushing (a minimum of 60 minutes) than non-penetrating corrosives (a minimum of 20 minutes). In all cases, if irritation persists, repeat the flushing procedure. It is important to get medical attention as soon as possible after first aid has been given. A physician familiar with procedures for treating chemical contamination of the eyes and body should be consulted. Note: The total amount of water in self-contained systems should exceed the volume required to deliver water at the recommended flow rates and flushing times. Emergency showers, also known as drench or deluge showers, are designed to flush the user’s head and body. They should not be used to flush the user’s eyes because the high rate or pressure of water flow could damage the eyes in some instances. Eyewash stations are designed to flush the eye and face area only. There are combination units available that contain both features: a shower and an eyewash. The need for emergency showers or eyewash stations is based on the properties of the chemicals that workers use and the tasks that they do in the workplace. A job hazard analysis can provide an evaluation of the potential hazards of the job and the work areas. The selection of protection — emergency shower, eyewash or both — should match the hazard. In some jobs or work areas, the effect of a hazard may be limited to the worker’s face and eyes. Therefore, an eyewash station may be the appropriate device for worker protection. In other situations the worker may risk part or full body contact with dangerous substances. In these areas, an emergency shower may be more appropriate. A combination unit has the ability to flush any part of the body or all of the body. It is the most protective device and should be used wherever possible. This unit is also appropriate in work areas where detailed information about the hazards is lacking, or where complex, hazardous operations involve many chemicals with different properties. A combination unit is useful in situations where there are difficulties handling a worker who may not be able to follow directions because of intense pain or shock from an injury. Although portable models are available, it is always a good practice to select a plumbed model whenever possible. Portable models should be able to deliver the same volumes of water, as well as meet the dimensions for plumbed models, as specified in the standard. However, portable stations are necessary for mobile crews, temporary locations, or when the plumbed model is under repair. In order to prevent any secondary eye infections, the water in self-contained models should be treated to prevent bacterial growth in the water itself. Changing the water supply weekly is another good preventative measure. Emergency Showers The emergency shower should deliver a pattern of water with a diameter of at least 20 inches at 60 inches. This diameter ensures that the water will come into contact with the entire body - not just the top of the person’s head. ANSI also recommends the shower head be between 82-96 inches from the floor. The minimum volume of spray should be 20 gallons/minute for a minimum time of 15 minutes. The shower should also be designed so that it can be activated in less than 1 second, and it remains operational without the operator’s hand on the valve (or lever, handle, etc.). This valve should not be more than 69 inches in height. If enclosures are used, ensure that there is an unobstructed area of 34 inches in diameter. Eyewash and Eye/Face Wash Stations Eyewash stations should be designed to deliver fluid to both eyes simultaneously at a volume of not less than 1.5 litres/minute (0.4 gallons/minute) for 15 minutes. However, the volume should not be at a velocity that may injure the eyes. The unit should be between 33 to 45 inches from the floor, and a minimum of 6 inches from the wall or nearest obstruction. The user should be able to open their eyelids with their hands and still have their eyes in the liquid. As with the shower, the unit should also be designed so that it can be activated in less than one second, and it remains operational without the operator’s hand on the valve (or lever, handle, etc.) with the valve being located in an easily located place. Since the nozzles to eyewash stations typically need to be protected from airborne contaminants, the units are to be designed such that the removal of these covers should not require a separate motion by the userwhen the unit is activated. Personal Wash Stations Designed to deliver flushing fluid immediately, personal wash stations can be used while transporting the victim to the permanent eyewash station or medical facility. These stations do not replace the requirement to have a 15 minute-supply eyewash station. The expiration date of the fluid should be printed permanently on the unit. Drench Hoses This type of equipment is usually considered to be secondary to proper emergency showers and eyewash stations (e.g., having a drench hose does not replace the need for showers/stations). Drench hoses may be used to “spot” rinse an area when a full shower is not required, to assist a victim when the victim is unable to stand or is unconscious, or to wash under a piece of clothing before the clothing is removed. Combination Units This name refers to equipment that shares a common plumbing fixture. Any of the fixtures such as shower, eyewash, eye/face wash or drench hose may be in this combination, but most commonly it refers to a shower and an eye wash station. It is important that pressure and volume requirements for each piece of the unit (as described above) are in compliance with the code. To be effective, the equipment has to be accessible. ANSI recommends that a person be able to reach the equipment in no more than 10 seconds. In practical terms, consider that the person who needs the equipment will be injured, and may not have use of their vision. Recommendations for this distance in linear terms range from 50 to 100 feet. However, the “10 second” rule may be modified depending on the potential effect of the chemical. Where a highly corrosive chemical is used, an emergency shower and eyewash station may be required within 10-20 feet from the hazard. These units should be installed in such a way that they do not become contaminated from corrosive chemicals used nearby. The location of each emergency shower or eyewash station should be identified with a highly visible sign. The sign should be in the form of a symbol that does not require workers to have language skills to understand it. The location should be well lit. Other recommendations include that the emergency shower or eyewash station should be: • Located as close to the hazard as possible; • Not separated by a partition from the hazardous work area; • On an unobstructed path between the workstation and the hazard. (Workers should not have to pass through doorways or weave through machinery or other obstacles to reach them.) • Located where workers can easily see them — preferably in a normal traffic pattern; • On the same floor as the hazard (no stairs to travel between the workstation and the emergency equipment); • Located near an emergency exit where possible so that any responding emergency response personnel can reach the victim easily; • Located in an area where further contamination will not occur; • Provide a drainage system for the excess water (remember that the water may be considered a hazardous waste and special regulations may apply); • Not come into contact with any electrical equipment that may become a hazard when wet; and • Protected from freezing when installing emergency equipment outdoors. The 2004 ANSI standard recommends that the water should be “tepid” but does not give a specific temperature. Other sources will use the term “lukewarm water”. ANSI does provide a guideline that the water temperature should be under 38°C (100°F) and above 15.5°C (60°F). Temperatures higher than 38°C (100°F) are harmful to the eyes and can enhance chemical interaction with the skin and eyes. Long flushing times with cold water (less than 15.5°C (60°F) can cause hypothermia and may result in not rinsing or showering for the full recommended time (ANSI 2004). With thermal burns (injuries to the skin), the American Heart Association noted that optimal healing and lowest mortality rates are with water temperatures of 20-25°C (68-77°F). Remember that any chemical splash should be rinsed for a minimum of 15 minutes but rinsing time can be up to 60 minutes. The temperature of the water should be one that can be tolerated for the required length of time. Water that is too cold or too hot will inhibit workers from rinsing or showering as long as they should. Install anti-scalding devices (temperature control valve or thermostatic tempering valve), constant flow meters, and other devices that will help maintain a constant temperature and flow rate. For cold or outdoor locations, emergency showers with heated plumbing are available. In hot climates, outdoor emergency showers should also have a tempering valve so that workers are not exposed to water that is too hot. FSM
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