ANSI/ISEA Z358.1 Explained: Emergency Eyewash and Shower Requirements

A corrosive is in use somewhere in your building and an audit or a plumbing inspection is coming. ANSI/ISEA Z358.1 sets what the emergency eyewash or drench shower has to do: 15 minutes of tepid flushing fluid at 60 to 100°F, 0.4 gpm for an eyewash and 20 gpm for a shower, a hands-free valve that opens in one second or less, and a fixture no more than 10 seconds away on the same level with a clear path. Every figure below is traced to Bradley's guide to the standard, Hughes Safety's summary, ISEA's own selection and use guide, or OSHA's pages.

What the standard is and who publishes it

ANSI/ISEA Z358.1, the American National Standard for Emergency Eyewash and Shower Equipment, is written and published by the International Safety Equipment Association (ISEA). The current edition is Z358.1-2014, reaffirmed in 2020, which ISEA cites as ANSI/ISEA Z358.1-2014 (R2020). Bradley's guide calls it a voluntary standard: it binds no one by itself and gets its force from the regulators and codes that point to it. Its sections run by equipment type, showers (4), eyewash (5), eye/face wash (6), combination units (7), and supplemental equipment (8), each covering performance, installation, testing, maintenance, and training.

How OSHA and the plumbing codes use it

The federal rule is one sentence, OSHA 29 CFR 1910.151(c): "Where the eyes or body of any person may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing of the eyes and body shall be provided within the work area for immediate emergency use." It never defines suitable. OSHA's letters of interpretation do: the April 18, 2002 letter says Z358.1 was not adopted by OSHA and so is not enforced as a regulation, and the November 1, 2002 letter says OSHA "has often referred employers to ANSI Z358.1 as a recognized source of guidance" when judging whether a facility is suitable. ISEA's guide adds that the International Plumbing Code (section 411) and the Uniform Plumbing Code (section 416) require Z358.1-compliant equipment wherever eyewash or shower equipment is needed, and that many states cite it directly. Which edition your inspector holds you to is the authority having jurisdiction's call, so confirm the layout with the AHJ.

The equipment classes it covers

In both tables, Bradley is Bradley's Z358.1 guide, Hughes is the Hughes Safety summary, and ISEA is ISEA's selection and use guide.

Two details buyers miss: ISEA says a faucet-mounted eyewash must meet every eyewash requirement, including the one-second valve, and Bradley notes that compliant fixtures ship with stay-open ball valves.

Every numeric requirement

Clause numbers are the ones Bradley's guide cites for the 2014 edition; the standard itself is paywalled and is not quoted here.

Tepid water and mixing valves

The standard defines tepid as a temperature that keeps a person flushing for the full 15 minutes, with 60 to 100°F as the suitable range. Above 100°F, ISEA and Hughes say, water can harm the eyes, speed the chemical reaction, and increase absorption through the skin; at 60°F and below, Bradley says, hypothermia becomes a concern, and Hughes adds that the casualty cannot then complete the full 15-minute flush. ISEA notes that in many locations the cold supply runs below 60°F, so the owner tempers it with a thermostatic mixing valve, a tankless heater, or a heated storage tank, and a mixing valve may be required by code even with a tank. A TMV blends hot and cold to a set outlet temperature and holds it as the supplies drift; one built for emergency fixtures also reduces or shuts off the flow if the cold supply fails, so scalding water never reaches the fixture, and keeps cold water running if the hot fails. Local plumbing codes may require ASSE 1071, so ask the AHJ, and size the valve for every component of a combination unit running at once.

What an inspector checks

ISEA's annual inspection checklist is the closest thing to the inspector's clipboard: installed per the manufacturer's instructions, reachable in 10 seconds, on the same level, clear path, highly visible sign, well-lit area, spray pattern and flow rate right for the equipment type, tepid fluid at 60 to 100°F, and a valve that stays open without hands. Between annuals, the weekly record is what gets asked for. Bradley's checklist runs each plumbed fixture long enough to clear the supply line (ISEA says the aim is to flush every dead leg, so the time depends on the piping, not on a fixed number), checks the eyewash pattern with a gauge and the shower flow with a tester bucket, reads the temperature, and dates the unit's inspection tag and a central log. Self-contained units get a weekly visual check that fluid is present, not an activation.

Buying to meet it

Plumbed or self-contained. ISEA's hazard assessment starts with whether there is plumbing near the exposure point. ISEA says that answer decides whether you can choose between a plumbed and a self-contained unit; with plumbing, a plumbed fixture on tempered water is the usual choice. Without it, a self-contained unit (a gravity-fed portable eyewash or a tank shower) holds its own fluid and must still deliver the 15-minute flow. Its fluid has a limited life and is changed on the manufacturer's schedule, kept clean with a bacteriostatic additive or supplied as sealed sterile cartridges; the reservoir is refilled or replaced after every use, and the unit gets a weekly visual inspection and cleaning. A personal wash bottle is not a substitute.

Combination units. Where a splash could reach the body as well as the eyes, ISEA points to a combination shower and eyewash or eye/face wash on one supply; every component meets its own section, and the supply and mixing valve carry all of them at once for 15 minutes.

Freeze protection. Where the fixture could face freezing, the standard calls for freeze-protected equipment. ISEA describes electric heat tracing under insulation and an ABS jacket, frost-proof hydrant designs with the valve below the frost line and a drain-down after use, and mounting through the wall of a heated space with the valves inside; heated blankets cover self-contained units. ISEA gives 40°F as the point a freeze bleed valve typically opens and 95°F for a scald valve; Bradley warns that the water either one dumps is a slip hazard and has to be piped away.

Drain. A compliant shower at 20 gpm puts out 300 gallons in 15 minutes, by Bradley's arithmetic, and ISEA says to consult local authorities on the waste water. Settle the drain, or the containment, before the fixture goes in.

What to send with a quote request. ISEA's hazard assessment questions, in short, plus what its tepid water and waste water sections need:

• The product, and whether its safety data sheet calls for flushing on skin or eye contact
• Eyes only, or eyes, face, and body, and how many people could be splashed at once
• Distance from the exposure point to the proposed fixture, and any stairs or doors on the route
• Whether there is plumbing near the exposure point
• The cold supply temperature if known, whether hot water is available, and where the flushing water will drain
• Indoor or outdoor, and whether the spot freezes, gets very hot, or is dusty

Next steps

Time the route in seconds and check the cold water at the nearest tap, then see what we quote on the emergency eyewash stations and emergency safety showers pages of our safety equipment division: plumbed and self-contained fixtures, combination units, thermostatic mixing valves, freeze-protected models, and signage, from Bradley, Haws, Guardian, and Speakman. The OSHA safety equipment guide covers the rest of 29 CFR 1910. Send your answers through the quote form and we will come back with fixtures, the mixing valve, and lead times.