Design Considerations

There are several important design issues that must always be addressed when selecting and installing emergency equipment. These include the following:

Location

In general, the ANSI standard provides that emergency equipment be installed within 10 seconds walking time from the location of the hazard. The equipment must be installed on the same level as the hazard (i.e. accessing the equipment should not require going up or down stairs or ramps). The path of travel from the hazard to the equipment should be free of obstructions and as straight as possible. Users of the equipment should not have to walk around machinery or other obstacles to reach the unit. However, there are certain circumstances where these guidelines might not be adequate. For example, where workers are handling particularly strong acids, caustics or other materials where the consequences of a spill would be very serious, emergency equipment should be installed immediately adjacent to the hazard. Laboratory environments may also require special consideration. It is common in many laboratory buildings to install emergency equipment in a corridor or hallway outside of the lab room. This may satisfy the provisions of the standard but still not provide workers with immediate access to emergency equipment. In these cases, consideration should be given to installing dual purpose eye wash/drench hose units at lab sinks. These units are highly accessible and versatile. They provide immediate protection for the eyes, face or body when a spill involves a relatively small amount of hazardous material. Please refer to the “Eye Wash/Drench Hose” section of this catalog for further information.

Water Supply

Proper operation of emergency equipment requires the availability of a large and continuous supply of potable water. The water supply must, at a minimum, be capable of delivering the volumes of water required by the ANSI standard. Piping should be at least as large as the inlet size of the unit to be installed. The water supply line must also be capable of delivering an uninterruptible flow of water of at least 30 PSI flow pressure.

Water Temperature

The ANSI standard provides that the water delivered by emergency equipment be “tepid” (that is, moderately warm or lukewarm). Tepid water is generally defined as between 60 and 100 degrees Fahrenheit. However, where it is possible that a chemical reaction might be accelerated by warm water, a medical professional should be consulted to determine what the optimum water temperature would be.

The delivery of tepid water to emergency equipment may raise complicated engineering issues. In geographical areas subject to cold weather, the water supplied by public water systems can be quite cold, at times just above freezing. Providing tepid water requires heating the cold water or blending it with hot water to achieve a desirable temperature. Conversely, in warm areas of the country, water standing in pipelines can be heated to a very hot temperature. Providing tempered water would then involve chilling the water or adding cold water to the water supply line.

There are several ways to design a water supply system to address the tepid water requirement. First, it is possible to provide both hot and cold water supply lines to each location at which emergency equipment is installed. This is typically done in facilities (such as laboratory buildings and schools) where hot and cold water systems are installed throughout the building. At each emergency unit, a tempering valve would be installed to blend the hot and cold water to a preset temperature. The tempering valve must be specially designed for use with emergency equipment, since these valves have dual built-in safety features. In the event that there is an interruption in the hot water supply, the valve will still deliver a full flow of cold water to the equipment. If there is an interruption in the cold water supply, the valve will shut off the water entirely to eliminate the possibility of scalding. Please refer to the “Tempering Units” section of this catalog for information on Guardian tempering valves.

The second way to address the tepid water issue is to install a recirculating tepid water system. This system can supply multiple emergency equipment stations. The system continually recirculates warm water to each location. If one or more units are activated, the system will automatically blend hot and cold water and add it to the water line to supply the units. These systems must be sized and engineered for the particular facility in which they are to be installed. It is therefore common to consult with the emergency equipment manufacturer during the design process. Please contact our regional sales representatives or the factory for information on recirculating tempered water systems.

Water Disposal

The ANSI standard does not include any provisions regarding the disposal of waste water. However, consideration must be given to where waste water will go. In particular, care must be taken that waste water not create a hazard, by creating a pool in which someone might slip, or might freeze.

Most eye wash, eye/face wash and safety station units are designed with waste connections for connection to drain piping. Guardian recommends that units be connected to drain piping. For emergency showers and for other units without waste connections, floor drains should be provided. Floor drains are important for two reasons. First, emergency showers deliver a very high volume of water. This volume can cause significant water damage to the facility if drains are not provided. This concern is heightened where there is a possibility that units might be inadvertently operated. Second, the absence of drainage may be a deterrent to routine testing of emergency equipment. The testing process is more difficult if waste water must be manually collected and removed.

After an emergency eye wash or shower has been used, the waste water may contain hazardous materials that cannot or should not be introduced into a sanitary sewer system. It may be necessary to connect the drain piping from the emergency equipment or floor drain to the building’s acid waste disposal system or to a neutralizing tank.

Handicapped Accessibility

The Americans with Disabilities Act (ADA) mandates that workplaces be accessible to, and usable by, physically handicapped persons. Making workplaces accessible to handicapped persons has had an impact on how facilities are designed and the equipment installed in facilities. With respect to emergency equipment, ADA regulations impose requirements for maximum heights and reach, the types of actuators that are permitted, etc. Guardian offers specialized “barrier-free” products that will assist in complying with governmental regulations (28 CFR Part 36) and compliance standards (ANSI 117.1-1-1992). Please refer to the “Barrier-Free Units” section of this catalog for complete information.

Identification

ANSI Z358.1 provides that emergency units should be identified with highly visible signs. Without appropriate signage, emergency equipment can blend into the background of the surrounding area and be difficult to locate in an emergency. The signs used with emergency equipment should comply with the provisions of ANSI Z535.1 through ANSI Z535.5, utilizing a white background with green lettering. Graphics and lettering should be of the correct size and format. All Guardian signage conforms to these provisions.
In addition to identification with appropriate signage, the emergency equipment itself should be designed to provide maximum visibility. Guardian safety stations are furnished with safety orange polyethylene covers for the vertical piping. In addition to protecting the piping against corrosion, the orange covers assure that the equipment will be visible and readily identified in an industrial plant.
Finally, the ANSI standard recommends that the area around emergency equipment be well lighted. Guardian alarm units (see below) can be equipped with area lights to provide the necessary lighting.

Alarm Systems

Alarm systems are advisable for emergency equipment, particularly in remote locations or areas where only one employee might be working. Alarm systems serve two important functions. First, they serve to let facility personnel know that an accident has occurred and that a unit is in operation. This can help to insure that assistance is rendered as quickly as possible. Second, alarm systems can be a deterrent to unintended or malicious operation of a safety unit.

Alarm systems incorporate a flow switch installed in the water supply line to an emergency unit and a visual indicator light and/or audible alarm. When the unit is activated, the flow switch detects the movement of water in the line and sends a signal that activates the light and/or horn. In addition, the alarm can relay the same signal to a monitoring station or building management system.

Post-Installation Considerations

Simply installing emergency equipment is not a sufficient means of insuring worker safety. Employees must be trained in the location of emergency equipment and in its proper use. In particular, workers must be trained that, in event of an emergency, the affected area should be rinsed for at least fifteen minutes to assure that contaminants are rinsed away thoroughly and completely.

Most importantly, employers must develop a response plan to be used in the event that an accident does occur. The focus of the response plan should be to provide assistance to the injured worker as quickly as possible.

Finally, all emergency equipment must be activated at least weekly to assure proper operation. A testing log should be maintained to document the weekly check. At least annually, emergency equipment must be inspected to assure continued compliance with the ANSI standard.