subject: Water Temperature For Safety Showers [print this page] During accidents involving hazardous substances emergency eye baths and safety showers provide essential first aid. However, simply installing the equipment does not guarantee effective decontamination. Water temperature plays a key role in effective decontamination as if the temperature is too low or too high the casualties will not be able to stay under the shower for the recommended 15 minutes for decontamination.
The ANSI Z 358.1 2009 standard recommends that water delivered from an emergency safety shower should be at a temperature of between 16C and 38C. It also recommends a minimum flow of 75 litres a minute at 2.1 bar for at least 15 minutes.
Where the ambient temperature is high such as in the desert, solar radiation will quickly raise the temperature of water in storage tanks and pipe work to an unbearable level and make the shower unusable. For mains fed showers self-draining models offer a simple solution by removing water from the standpipe when not in use and therefore avoiding the risk of it being heated by the sun.
Unreliable mains supplies will often result in tank showers being used. Tank showers are available in a wide range of capacities, and Hughes provides showers with a capacity of 350 litres all the way up to 2400 litres. The 1200 ltr tank shower provides sufficient water for 15 minutes, the 2400 ltr tank shower for up to 30 minutes when no mains water supply is available.
To maintain a safe and usable water temperature in tank showers there are a number of techniques available. Extra insulation, reflective sun shields and chillers are all effective in hot climates. Chillers are mounted onto the side of a tank and activate when the temperature rises, ensuring that the temperature remains in the usable range of 16C and 38C.
Major advantages of a Hughes chiller is the ability to attach it to a tank shower already in use and the lower maintenance required.
Heating the tank shower is often required when in colder climates in order to maintain the safe water temperature.
Hughes design purpose built temperature controlled showers such as the Temperature Controlled range that are generally the most cost effective and practical solutions. The Temperature Controlled range heat water in a storage tank to about 60C, and mix a cold supply from the mains through a high flow rate thermostatically controlled valve. The resulting water supply at the shower head is between 25 and 35C.
It is important to discuss temperature requirements from the start of safety shower design as climate conditions can vary greatly. Hughes can guide you through the various issues involved with differing climates and help you find the most cost effective solution.
