Emergency showers

NO QUICK DIP

By Lesley Young

If everything goes wrong and a worker is splashed or splattered with dangerous chemicals, an emergency shower can still save the day.

The lab technician carrying the tube of metallic sodium, safely bathed in oil -- it combusts spontaneously when exposed to air and burns explosively in water -- might have been thinking how unusual it was to have such nasty stuff around. Perhaps that’s what distracted him, because he tripped.

Thinking quickly those last few instants on his feet, he gently lobbed the tube up and away, knowing he needed to distance himself from the metallic sodium before it made its inevitable contact with the air.

But, as bad luck would have it, the tube spun through the air and landed in a sink a few feet away, where it broke and made contact with both air and water. The resulting explosion blew the sink off its mounting and embedded bits of debris and burning sodium in the technician’s face and upper body.

Stunned, in pain and partially blinded, he know he had to get to an emergency shower. But the nearest shower was one floor up.

"This aggravated his injuries a great deal," says Kent Hillman, manager of health and hygiene at the British Columbia Workers' Compensation Board, who investigated the accident several years ago.

Eventually, the worker did recover from his injuries. At the time, he was assisted by co-workers to reach the shower on the second floor. But those first few seconds, when a shower can most effectively flush the skin, were lost. His pain was intensified, and his recovery lengthened.

A drench, or deluge or emergency shower is exactly what its various names implies. It’s a shower that’s located in the workplace close to areas where workers might, as one of the provincial regulations puts it, be "exposed to the hazard of injury to the skin due to exposure to a substance". Such as certain acids, bases or toxic substances that can penetrate the skin.

The theory behind emergency showers is equally simple: If you’re suddenly covered in some nasty substance, you have to get it off you as fast as possible, and jumping into a shower, perhaps tearing off your clothes in the process, is the quickest way. And emergency showers are designed to be turned on instantly, with a single, prominent chain pull or other device so that there’s no need to fiddle with knobs and temperature controls.

Emergency showers can also be used effectively in extinguishing clothing fires, or for flushing contaminants off protective clothing.

When a corrosive chemical or toxic substance comes in contact with skin, tissue damage begins immediately. An emergency shower provides on-the-spot decontamination. It's an integral component of workplace first aid programs.

It's also just a back-up system, according to Hillman, a "when-all-else" fails piece of safety equipment.

When the shower is reached quickly and used efficiently, the risk of long-term tissue damage can be reduced. However, the exposed part of the body must be flushed immediately and thoroughly; the rule of thumb is that a shower should be reached within 10 seconds and that flushing should last at least 15 minutes using a large supply of clean water under low pressure.

"Timing is of essence. Flushing an injury with water will minimize the damage that first-aid and emergency medical services will have to treat," says Hillman.

The recently updated American National Standard for Emergency and Shower Equipment ANSI Z358.1-1998, amends the section on the location of showers to be no more than 10 seconds walking distance from the hazardous location.

Matching the hazard

Employers are entirely responsible for ensuring appropriate emergency showers. Hillman says the B.C. regulation has been developed to allow employers the flexibility they need when it comes to choosing the right showers for their workplaces. In other words, it addresses the preliminaries, but it does not spell out which showers fit what hazards. Regulations in other provinces are similar. Showers are required "where there is a hazard of exposure".

The ANSI standards provides the most specific information (see sidebar, "Performance Requirements," page XX). It defines how emergency showers should be constructed, installed, operated and maintained, "but it doesn't address the hazards," says Bob Bowles, with Haws Emergency, a manufacturer of drench showers. "And [the standard developers] are not in an position to categorize the hazard and what shower fits it," he adds.

The requirements are purposely vague because there are so many different potential hazards and locations where emergency showers are required. Work areas and operations that may require showers include battery charging areas, laboratories, spraying operations, high-dust areas, dipping operations, and hazardous substance dispensing areas.

The ANSI standard states emergency showers should be used in the following circumstances:

* where large volumes of potentially injurious materials are present, for example, loading areas, continuous process operations areas, chemical storage areas; and

* where pressurized materials are present and a small volume release would result in a large affected areas, such as in laboratories, schools and maintenance departments.

Employers should conduct a job hazard analysis before choosing an emergency shower. All hazardous substances should be identified using the MSDS, or material safety data sheet, for the substance in question; it will indicate whether the risk of exposure to the substance requires an emergency shower, says Hillman.

While the ANSI standard indicates that shower duration should be at least 15 minutes, other references recommend a minimum 20-minute flushing period if the nature of the contaminants is unknown.

The Canadian Centre for Occupational Health and Safety, the CCOHS, has a draft guideline (which will soon be available on its web site's OSH Answers link) that suggests that showering times may vary depending on the substance. For example, a minimum five-minute flushing time is recommended for mildly irritating chemicals, at least 20 minutes for moderate-to-severe irritants and non-penetrating corrosives, and at least 60 minutes for penetrating corrosives.

The first step is to determine whether the chemical is a corrosive, because exposure will require more prolonged flushing to ensure complete removal than in the case of exposure to irritants. For skin (and eye) exposures, it is also important to know whether the substance is a penetrating or non-penetrating corrosive. (Non-penetrating corrosives are chemicals which react with human tissue to form a protective layer that limits the extent of the damage. Most acids are non-penetrating corrosives, whereas alkalis, hydrofluoric acid and phenol are penetrating corrosives.)

The type of facility chosen should match the hazard. For instance, in some jobs, the effect of the hazard may be limited to the worker's face and eyes. This is an important distinction. Here, an eyewash station is appropriate (see "Getting an Eyeful, April/May 1999, page 32). However, an emergency shower should not be relied on for flushing the eyes. Where there is a risk of full-body exposure, a shower is appropriate. Common sense indicates where there is a full-body risk, there is also a risk of exposure to eyes and face, which explains why combination eyewash/shower facilities are popular.

According to the CCOHS, a combination unit is the most protective device, "and should be used wherever possible." Combination units help to control unit installations costs and piping requirements in a workplace. When combination units are used, the water line must be sized to enable simultaneous steady flow of water to both shower and eyewash facilities, should joint usage be necessary.

Be cautious about buying hand-held drench hoses. They do not qualify as showers, and should be treated as supplements. "They will not give 20 gallons a minute, or the spray pattern you need," says Bowles.

Portable emergency showers -- innovative pop-up devices -- are used mostly by emergency rescue teams, such as firefighters and other first responders. In most cases, workplace hazards have permanent locations, so permanent showers should be used. Portable showers should not be set up and treated as permanent facilities. Besides being impractical, this approach is costly.

Cover the basics

Check provincial regulations and follow the ANSI standard to ensure emergency shower facilities meet the basic requirements. Bowles says that all requirements and standards were developed with the intent to encourage workers to use emergency showers. And employers should keep that in mind when choosing the facilities.

In other words, make sure the shower meets the requirements, and the on-site health and safety specialist should adapt the installation to the requirements of the site. Take, for instance, shower height: The ANSI standard suggests "not less than 82 inches nor more than 96 inches from standing level". But what if the injured worker is in no condition to stand? Or, what if disabled workers need access to the showers?

This same thinking should be applied to every facet of the shower, including the activation device. If you choose a foot pedal over a pull chain for activation, ensure the foot-plate is large enough to be pressed by someone who cannot see, for example.

Choosing emergency shower heads is clearer because the standard is so specific. They must be capable of delivering water at a minimum of 20 U.S. gallons, or about 76 litres per minute, according to the ANSI standard. The water pressure and nozzle design should allow water to be delivered at the recommended rate while not being so forceful that it could cause further damage to skin that has been exposed to corrosive chemicals. As for spray patterns, minimum requirements are specified.

* Water temperature. The 1998 ANSI replaced the provision indicating a range of water temperature with a vague requirement stating that the water must be "tepid".

"They don't define the temperature, and quite frankly, that makes it very subjective," says Bowles. In general, he says "tepid" means lukewarm, and that is between about 80 and 95 degrees F (26 to 35 degrees Celsius). Temperatures above 100 degrees F (37 C) have proven to be harmful to eyes and can enhance chemical interaction with body tissues.

When a plumbed system is being used, a temperature control valve should be installed in the water line. For cold, outdoor locations, emergency showers with heated plumbing are available. And temperature control systems are available to protect water against excessive heat. It is imperative however, that the "tepid" temperature be maintained for the duration of a shower.

Cold, hot and scalding protection valves, as well as a valve that combines all three temperature controls, are available. Nicholas Tallos, senior engineering manager for Therm-Omega-Tech Inc. recommends purchasing valves from manufacturers that produce their own actuators, to ensure little variance and less risk of complications.

When choosing valves, Tallos also says it’s important to ensure the valves are resistant to tampering and corrosion, and made of stainless steel and/or brass. They should also have good dirt-handling capability. Valves that are easily blocked by dirt will not perform properly.

* Control and alarm devices. Control devices, also called pull rods, push plates, flags, trays, pull cords, triangles or treadles, are the water flow activation devices. The control devices must be highly visible and easy to activate by feel alone.

Stay-open valves are required by the ANSI standard to ensure continuous flow while hands remain free to remove clothing, if necessary. Actuation of the device must provide water within one second.

Valves that automatically shut off after a certain period of time, to prevent flooding of a facility, are also available.

Bowles suggests that galvanized piping be used for most workplaces. "It is a sterile and a more cost-efficient way to construct a shower." When showers are located in the vicinity of corrosive substances, the equipment should be coated with or made of corrosion-resistance material.

At remote locations, often, there is no one around to aid an injured worker. Siren, horns and flashing lights are excellent notification devices for any location. If it is a remote location, Bowles says that the alarm system should be wired back to a master control to alert rescue personnel that assistance is needed at a specific location.

* Modesty. Recently, there was a debate about the issue of "co-ed" emergency showers at an oh&s news group Internet site. Someone at a laboratory asked whether "we ought to install a safety shower in the women's rest room [a good distance from the hazard], because some of the women would be uncomfortable undressing the lab."

The overwhelming response was that doing so would set a dangerous precedent. Not only would the shower be located at too great a distance from the hazard, but the restriction may unintentionally influence who can and who cannot lend a helping hand to an injured worker.

Nevertheless, modesty curtains are becoming increasingly popular, and they are acceptable for mild exposure incidents, where the worker can help herself or himself. But as Bowles says, for severe injuries when some clothing may already be dissolved by the chemical -- and the worker is thrashing violently in pain -- modesty is not an issue and the curtain will quickly become useless.

Besides, he says, "You often want workers to take off their clothes. Clothes retain the chemical and can prolong the exposure to the skin."

While "modesty" is not addressed in the ANSI standard, curtains or other enclosures may encourage workers to use the showers when they need them. Enclosed showers are available, however, they should not limit the injured worker's entry or the application, leaving a minimum unobstructed area of 34 inches in diameter. Modesty concerns should be identified and discussed in training sessions on emergency showers.

Encourage use

According to Hillman, workers do not use emergency showers enough. Either they make a joke about them, or they haven't been properly trained in their use. He says getting to the shower must be a worker’s first reaction when injured. "Workers should be trained in their use, so there is no hesitation."

Most experts agree that training in emergency showers is often overlooked. The ANSI standard requires all personnel to know how, when, where and for how long to use emergency showers (and eyewash) equipment, as well as what they should do after an initial irrigation is complete. CCOHS recommends that written instructions be made available to all workers and posted beside the shower so that workers become familiar with them.

Kent Hillman keeps coming back, however, to the point emergency showers are a "back-up". If an emergency shower is needed, he says, it also means that every other engineering control should be in place, that workers should be fully trained in dealing with the hazard, and that all required personal protective equipment must be used. Only if all else fails should the shower be used as the first step in first aid.

Lesley Young is a freelance writer based in Toronto.

Sidebar

ANSI Performance Requirements

* Shower height: Not less than 82 inches nor more than 96 inches from standing level.

* Water spray pattern: Twenty inch minimum diameter, 60 inches from standing level.

* Centre of water spray: Sixteen inches from any obstruction.

* Potable water delivery: Minimum of 20 gallons (76 litres) per minute.

* Control valve and actuator: "Stay on" type ("Off" and "On" in one second) easily located.

* Location to hazard: Minimum 10 seconds travel.

* Identification: Well-lit, sign, area highly visible.

* Delivered water temperature: 60 degrees to 90 degrees.

* Freeze protection required: Manual or electrical.

* Hostile environmental protection: Enclosure, heated/non-heated.

* Alarms required: Local and/or remote.

* Modesty curtain: Does not discourage equipment use.

* Material safety data sheets: Available on file in safety or medical department.

* Medical assistance: Available in-plant or outside.

* Inspection: Monthly records should be maintained.

* Maintenance: Each unit activated weekly to flush line and verify flow.

* Training: Instruct all employees on proper use of equipment.

Sidebar

Tips

* Reducing the risk of incidents requiring emergency showers is the first objective, says Kent Hillman of the B.C. WCB. An emergency eyewash and shower risk assessment is an opportunity to review work practices, ergonomics, personal protective equipment, WHMIS and hazardous materials handling. Move to mitigations of chemical contact only after doing the best job possible in prevention, he adds.

* Check with first aid providers about needs arising from your WHMIS inventory and incidents recorded in the first aid log. Some materials such as hydrofluoric acid, metallic sodium, potassium and cyanides require special consideration.

* One worker in the area should be designated responsible for inspecting and operating the emergency shower weekly.

* Test and check the showers for flow, temperature and water quality weekly. "A lot of people never test them," says Hillman. "There can be a build-up of bacteria and microbes in the water in certain facilities and under conditions." The water should be drinkable. Let the water flow for at least three minutes each week.

* Preventive maintenance inspections should be done every six months to check for valve leakage, clogged openings and lines, and adequacy of the fluid volume.

* Keep good maintenance records, but keep it simple, says Hillman. A maintenance tag on portables with an inspection log and maintenance instructions has provided valuable assistance to many new safety committee members, as well as inspectors, he adds.

* Extra overalls and foot covers should be stored near emergency showers for use if needed afterwards.

* Make all workers aware of the shower, what it is, where it is and when to use it. Provide training during job orientation and update it periodically.

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