The importance of tepid water

08 December 2020

THE EUROPEAN standards, EN15154 and the international standard for safety showers and eye/face wash equipment, ANSI Z358.1-2014 specify that water delivered by an emergency safety shower must be tepid.

What is tepid water?

Tepid water is controlled within a fixed temperature range. For EN standards this is stipulated as 15 to 37C (59 to 98F). The ANSI standard specifies 16 to 38C (60 to 100F).

Why is tepid water important?

Safety showers provide immediate relief for employees splashed with hazardous chemicals. The water, delivered at a minimum of 76 litres per minute for 15 minutes, washes the chemical from the skin and out of the eyes.

A safety shower that operates outside of the tepid water range can cause more harm to a victim. A shower that is hotter than 38C can scald the injured person adding temperature burns to their injuries and increasing the chance of absorption of the chemical into the skin.

Adversely, a person is likely to leave a cold shower that is below 16C before the recommended 15 minutes of decontamination is complete. This exposes them to ongoing chemical burns. A safety shower that is too cold may even induce hypothermia in a casualty.

Tepid water shower options

Emergency Tank Showers with tepid water

Emergency tank showers are ideal for areas where water supply pressure and flow are unreliable or where there is no constant water supply. The integrated tanks contain enough water to meet the 15-minute minimum specified by EN and ANSI standards.

For hot climates, tank showers can be fitted with a cooling system to counteract solar radiation to ensure the water in the tank is kept to a tepid temperature. There are three different cooling options available:

  • Non-flameproof

    • Side mounted

    • Fitted with air-filter to prevent ingress of dust/sand

    • Ability to set required water temperature

  • Flameproof

    • Suitable for hazardous environments

    • Fitted with explosion proof control panel

    • Ability to set required water temperature

  • Hughes Zero Power Cooler

    • No electricity required

    • Service and maintenance free

    • Zero operational costs

    • Suitable for hazardous environments

For cold climates, tank showers can be immersion heated or jacketed to protect the water in the tank from freezing and to help maintain it within the tepid range.

A specialized solution for frigid or Arctic climates is the Polar Tank Shower. Fiberglass panels and doors insulate the shower area. A room heater keeps the interior temperature at a comfortable level, ensuring a victim is not left out in the cold.

Temperature Controlled Safety Showers

temperature controlled emergency safety shower has its own water tank with heater. This hot water is then mixed with the a cold plumbed in supply via a thermostatic mixing valve to deliver tepid water on activation regardless of the ambient conditions.

These units are designed to remain on standby to deliver warm water for over 15 minutes, conforming to European and ANSI standards. The integral heated water tank can also be used as a warm water source to feed other emergency shower units in the vicinity.

Freeze-protected Showers

Freeze-protected units are insulated and trace-tape heated to prevent the water in the safety shower from freezing. However, tepid water must be supplied via the mains supply, these units do not heat the water to a tepid temperature.

Self-draining Showers

Self-draining safety showers are designed for tropical climates where solar radiation can heat standing water within the pipes of an emergency safety shower to temperatures as high as 50C.

The design of these models allows standing water to drain away from the standpipe so that it doesn’t heat up in the sun. This ensures that tepid water that is supplied to the shower remains tepid.

View the free ANSI and EN standard summaries for more information