1.  Shut-off valves

The water supply to showers and/or shower/eyewash combination units should be controlled by a ball-type shutoff valve which is visible and accessible to shower testing personnel in the event of leaking or failed shower head valves. If shut off valves are installed in the supply line for maintenance purposes, provisions shall be made to prevent unauthorized shut off.

  •   Good Practice per Stanford EH&S
  •   ANSI Z358.1-2014, Section 6.4.5.

This design will make maintenance easier.

2.  Floor Drains

Where feasible, floor drains should be installed below or near safety showers, with the floor sloped sufficiently to direct water from the shower into the sanitary sewer drain.

  • Good Practice per Stanford EH&S
  • Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards, Updated Version

Floor drains will minimize the potential for excessive flooding, which may damage laboratory facilities and equipment, interrupt laboratory operations, cause a reluctance to use the safety shower or to use it for a sufficient amount of time, and create a slipping hazard. Floor drains will also facilitate required monthly testing.

Any floor drain which may be in service during safety shower use shall be installed with a temporary plug which remains closed except when the shower is in use or protected from spills by a covered sump or berm system.

  • Palo Alto Municipal Code, 16.09.175(a)(3)

The installation of a floor drain, temporary plug, covered sump, or berm shall not project into the walking surface so as to create a tripping hazard. Walkways shall be stable, planar, flush, and even to the extent possible. As a minimum level of care, changes in levels between 1/4 and 1/2 inch (6 and 12 mm) shall be beveled with a slope no greater than 1:2 (rise:run). Changes in levels greater than 1/2 inch shall be transitioned by means of a ramp or stairway that complies with applicable building codes, regulations, standards, or ordinances, or all of these. The installation of a berm must not impede the flow of water from the emergency shower into the floor drain.

  • T8 CCR 3273(a)
  • ASTM F1637-13

3.  Where feasible, eyewash basins should be plumbed to sanitary sewer drains.

  •   Good Practice per Stanford EH&S
  •   Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards, Updated Version

Drains will minimize the potential for excessive flooding, which may damage laboratory facilities and equipment, interrupt laboratory operations, cause a reluctance to use the eyewash or to use it for a sufficient amount of time, and create a slipping hazard. Drains will also facilitate required monthly testing.

4.  Modesty curtains should be considered for emergency showers. When installed, a minimum unobstructed area of 34 inches shall be provided.

  •   Good Practice per Stanford EH&S
  •   ANSI Z358.1-2014, Section 4.3.

The removal of contaminated clothing while using a safety shower is essential. Modesty curtains remove a potential impediment to use and encourage the removal of contaminated clothing.