OSHA does not specify a water temperature for eyewashes or showers under 1910.151(c), but addresses the issue in an April 18, 2002 Letter of Interpretation by saying, “it is the employer’s responsibility to assess the particular conditions related to the eyewash/shower unit, such as water temperature, to ensure that the eyewash/shower unit provides suitable protection against caustic chemicals/materials to which employees may be exposed.”
OSHA also says that water which is too hot or too cold will prevent the affected person from flushing the eyes for the full 15 minutes recommended in emergency situations or on most SDSs. ANSI Z358.1-2009 provides more specific guidance by recommending a temperature range of 16-38 degrees Celcius (60-100 degrees Fahrenheit) for flushing fluid used in all eyewashes and showers.