Page 27 - Occupational Health & Safety, May 2018

EMERGENCY SHOWERS & EYEWASH
Creating a ‘Comfort Zone’ for Emergency Equipment Water Temperature
Tempered water has been a hot topic of late, but just as many installations need cooling of high-temperature supply water. BY SAMANTHA HOCH
www.ohsonline.com
MAY 2018 | Occupational Health & Safety 23
Moving water transfers heat, either in- creasing the temperatures of the ob- jects it contacts or decreasing them. Heat transfer, via moving water, made
twentieth century man more productive and more comfortable. It sped up transportation and made a wealth of innovative products possible. But while the physical properties of heat transfer via water move- ment can certainly be beneficial, there are many in- stances when temperatures must be controlled with- in a high and low range to avoid injury. For many years, industrial emergency equipment was not one of those instances. The water that flowed through emergency showers and eyewashes was subject to climatic, source affected, and other ambient vari- ables that could raise it to injurious temperatures or lower it to downright freezing temperatures.
Municipally supplied water, when running for a sustained period, tends to cool down or even heat up, eventually approaching its source point temperature. And, by the same token, water subjected to hot or cold ambient temperatures in manufacturing plants or elsewhere can become dangerously hot or cold. Presently, OSHA, at 29 CFR 1910.151(c), requires the availability of suitable first aid treatment facilities. Specific direction is given indicating that “suitable fa- cilities for quick drenching or flushing of the eyes and body shall be provided.”
While the definition of “suitable” was mostly left up to the specifier in the past, the current ANSI/ISEA Z358.1-2014 standard provides much greater clarity. ANSI mandates a water delivery temperature range defined as “tepid.” This is clarified as a 40-degree tem- perature range for flushing fluids spanning from 60 degrees F to 100 degrees F [16 degrees C to 38 degrees C]. Yet, no source information proves that 60 degrees F for 15 minutes in potentially freezing outdoor con- ditions will not lead to hypothermia. Nor is there sup- porting documentation to verify that 100 degrees F would not scald or further injure the delicate eye tis- sues or skin.
The thought of an injured worker short-cutting the required emergency equipment use cycle because the water is too cold or hot has led to the notion of the “Comfort Zone”—a revised outlet water temperature range that ensures comfortable, non-injurious use for the full 15-minute use cycle.
Revisions to the ANSI/ISEA Z358.1 standard have occurred on a somewhat routine basis. Published in 1981, the standard was updated in 1990, 1998, 2004, 2009, and most recently in 2014, with the expectation of another update on the horizon. It is suggested that a revised water temperature range between 70 degrees F and 95 degrees F can help ensure medically effective results and provide that best practice comfort zone. In- creasing the minimum flushing fluid temperature to 70 degrees F can encourage users to use the equipment for the full 15-minute flush cycle, protect against cold shock that could lead to cardiac arrest, and advocate for the removal of contaminated clothing. Decreasing the maximum temperature to 95 degrees F will help avoid temperatures known to harbor specific bacteria growth, prevent scalding of the eyes and skin, and re- duce the chances of an increased chemical reaction.
So, how do you ensure a facility’s equipment falls within the comfort zone? For the sake of this discus- sion, we will assume that the plant has sufficient
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