Introduction
Working with hazardous materials can be harmful; but in some workplaces, contact with such materials is inevitable. If you wish to review our selection of tools suitable for workplaces with dangerous materials. Unwanted contact can occur even with protected skin and eye gear. If not correctly attended to, such exposure can cause permanent damage. As such, international standards suggest washing exposed areas with tepid water immediately to clean away contaminants.
Because of the involved risks, workplaces that pose the risk of exposure to corrosives must have an emergency shower or an eye wash station readily available for use. International guidelines such as European Standards EN15154 and American National Standards Institute ANSI/ISEA Z358.1-2014 are the most established standards that regulate the implementation of safety shower and eye wash stations.

If you’d like to learn more about emergency showers and eye wash stations, click here to read our related article. In this one, however, we will focus on tepid water and its specifications.
What Is Tepid Water?

ANSI/ISEA Z358.1-2014 defines tepid water as moderately warm water. Although the standard does not provide a specific temperature value, it suggests that tepid water should not be below 60 °F to prevent hypothermia or above 100 °F to eliminate the risk of scalding. In addition, different chemicals react in various ways with water at different temperatures; therefore, there is necessary and conscious ambiguity in international standards.
How to Ensure Water Delivery at Correct Temperatures?
As mentioned above, water delivery at the correct temperature range is critical in emergency systems. ANSI/ISEA Z358.1-2014 states that all emergency drenching stations must have an adequate supply of tepid water for a minimum drenching time of 15 minutes. Exposure to water at temperatures above the limit for the required amount of drenching time can cause severe burning, blistering, and scarring of skin and eyes. On the other hand, exposure to water at below-limit temperatures poses the threat of hypothermia, especially in scenarios that require full-body drenching.
There is a variety of equipment and preventative measures that ensure water delivery at correct temperatures. The most common solution for providing tepid water is incorporating a thermostatic mixing valve into your plumbing system. Thermostatic mixing valves mix cold and hot water to maintain a predetermined water temperature, even if the input temperatures fluctuate. The use of thermostatic mixing valves specific to emergency system usage is crucial since they ensure the delivery of cold water, even if hot water is unavailable.
Another alternative to provide emergency systems with water at ideal temperatures is tankless water heaters. Tankless water heaters provide on-demand tepid water. Cold water is heated using gas or electricity. To prevent scalding, tankless heaters are equipped with safety shut-offs and can deliver cold water if disabled.
Heated storage tanks are another solution that provide tepid water. An immersion heater keeps the water at the desired temperature at all times. Plumbed and self-contained tanks are available. In either case, the system should involve main safety measures such as thermostatic mixing valves to prevent scalding.
Placement or heat-proofing of water storage units and plumbing is crucial. If placed near heat sources such as furnaces and burners, tepid water inside storage units may go above the allowed limits and cause scalding when used. Water temperatures inside water delivery systems may also rise with exposure to sunlight or radiation. Likewise, insulating the emergency system would behoove protecting against freezing.
What Are Other Important Parameters?
There are other salient criteria to meet in addition to water temperature.
Tepid water is commonly used for the ablution of corrosives after contact; thus, pH levels are another crucial factor to consider. The neutralizing reaction is a chemical interaction between acids and alkalis. When an alkali reacts with an acid, they neutralize each other, releasing salt in the proses. pH neutrality is a must for water to be used in an emergency drenching station since a possible neutralizing reaction occurring on human tissue can lead to health hazards.
Tepid water should also be free of contaminants. The goal of using tepid water is to clean corrosives and hazardous materials; therefore, care must be taken to ensure the water supply of emergency systems are clean.
Conclusion
The term “tepid” is used to describe water that is suitable for emergency drenching system use. According to recognized international standards, there are crucial criteria to be met before feeding a drenching fluid into a wash station; however, tepid water can be easily supplied and delivered using information curated in this article.