Your Guide To The ANSI Z358.1 Safety Shower & Eye Wash Regulations

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The Ultimate Guide to ANSI Z358.1 Regulations

If you’ve ever thought about installing a safety eye wash unit or decontamination shower in your workplace, you’ve no doubt come across the ANSI regulations. But what exactly are they, and what do they mean for you, the end user?

In this guide, we’ll explain what the ANSI Z358.1 regulations are for, and what you need to do in order to comply with them; but first, we’ll take a look at the ANSI itself.

About the ANSI

The ANSI - or American National Standards Institute - was founded back in 1918 when, at the behest of the US government, five engineering societies merged to form a single, nationwide standards organisation.

A private, not-for-profit organisation, the ANSI’s purpose today is to oversee voluntary industrial standards in the private sector, both in the US and internationally. According to the ANSI themselves, ‘the institute oversees the creation, promulgation and use of thousands of norms and guidelines that directly impact businesses in nearly every sector’.

About the regulations

The ANSI administers many thousands of different industrial standards; the specific set of standards we’re interested in is called ANSI Z358.1. These are the regulations that govern the manufacture, installation and use of safety eye wash equipment and emergency decontamination showers.

Originally drawn up by the ANSI in 1981, they have since been adopted health and safety organisations across the world. During that time, the regulations have gone through multiple revisions, the latest of which was in 2014. All of the products on conform to this latest version.

Emergency decontamination units are designed for use in situations where the user’s skin or eyes have come into contact with corrosive, injurious substances. They work by drenching the affected area with water in order to flush away the harmful material and prevent further injury. Corrosive, injurious substances include the following:

Eye wash stations

The ANSI regulations allow for two different kinds of eye wash station:

In order to be compliant with the ANSI standards, both types of eye wash station must:

  • Discharge water at a rate of 0.4 gallons per minute at a pressure of 30 PSI for at least 15 minutes
  • Be capable of being activated in under one second, via a hands-free, stay-open valve
  • Flush and irrigate both eyes simultaneously

Eye and face wash stations

Eye and face wash stations are broadly similar to eye wash equipment with regards to location, activation and so on; the primary difference is that water is delivered at a rate of three gallons per minute.

Decontamination showers

Emergency drench showers come in many different forms, such as freestanding, ceiling mounted and wall mounted. Whatever the configuration, they must:

  • Deliver water at a rate of 20 gallons per minute at 30 PSI for a full 15 minutes
  • Be fitted with a valve that can be easily opened in one second or less and stay open until intentionally turned off

Combination units

There are a number of combination units on the market, which comprise an eye wash station and safety shower brought together in a single unit. The rules regarding water pressure and flow rate for each component are the same as their respective standalone equivalents, under the proviso that both the eye wash station and safety shower are capable of running simultaneously.

Location, location, location

All of the emergency drench showers, safety eye and face wash stations and combination units sold at comply with the above standards; however, in order to be fully compliant, each unit must positioned in accordance with the regulations. The onus is on you, the end user, to ensure that the unit is installed in the correct manner.

In general, each unit should be located on the same floor as the hazard (i.e. the user should not have to travel up stairs). It should also be placed within a 10-second walk of the hazard, and the route should be clear of obstruction. The area around the unit should be well lit.

With regards to eye wash units, the spray head assembly must be positioned at least 6” (15.23 cm) away from any walls, and stand between 33” (83.9 cm)  and 53” (134.6 cm) inches from the floor.

Decontamination showers should be installed so that the bottom of the shower head is between 82” (208.3 cm) and 96” (243.8 cm) from the floor. The centre of the water pattern (best imagined as a straight line travelling from the centre of the shower head to the ground) should be at least 16” (40.6cm) from any obstruction.

The activation rod on a decontamination shower must be positioned no higher than 69” (173.3 cm) from the floor.

Water temperature

The water delivered to a plumbed-in eye wash station or emergency shower must be tepid (i.e. between 16° and 38°C). The easiest way to ensure that water is of the correct temperature is to install a thermostatic mixing valve, which mixes hot and cold water to a predefined temperature before it is delivered to the unit.

When it comes to portable eye wash stations, any potable water will suffice; however, it is recommended that the water is treated with a water preservative and replaced every six months. All of the portable eye wash stations in the come complete with a supply of water preserving solution, which inhibits the growth of bacteria.

Water freezing

If your safety equipment is to be installed in areas that carry a risk of water freezing (whether in outdoor areas, or in indoor areas such as cold rooms), you must take appropriate steps to ensure that the water supplied to your safety showers and eye wash units is free from the risk of water freezing.

These steps could include a temperature-activated bleed valve, pipe insulation, or electronic heating.


All safety equipment should be subjected to annual functional testing and regular maintenance to ensure that it is compliant with the regulations and ready for use in an emergency. Refer to the manufacturer’s instructions for information on how to carry this out.

The ANSI regulations also state that plumbed-in eye wash stations and decontamination showers must be “activated weekly for a period long enough to verify operation and ensure that flushing fluid is available”. Portable emergency equipment, on the other hand, need only be “visually checked to determine if flushing fluid needs to be changed or supplemented”.


It is vital to ensure that all employees are trained on the location and use of emergency decontamination equipment. Not only is this a requisite of compliance, but it also ensures that safety equipment can be located and operated swiftly and effectively in an emergency situation.

Drench hoses

While drench hoses cannot be used in place of safety showers or eye wash units, they can be included as supplementary equipment; indeed, many of the eye wash stations and emergency showers on (including our combined emergency shower and eye wash) can be fitted with augmentary drench hoses if desired.

The same rules and regulations governing water temperature and flow rate for safety showers are also applied to drench hoses. They should be activated weekly and tested for compliance every year, as with all other safety decontamination equipment.