Are You Putting Your Employees at Risk?
When the contaminant is a burn-inducing chemical, some argue the drenching time should be extended to a minimum of 20 and even 30 minutes of tepid water.
- By Richard E. Allred, Janet Dickinson
- Sep 01, 2012
In order to handle the complexities of chemical spill contamination on an employee's clothing, there is an argument that suggests that just 15 minutes of drenching time may not be long enough.
In 2009, the ANSI standard for emergency safety showers Z358.1 was revised, and one of the most important changes made at this time was the requirement that safety showers must provide 15 minutes of tepid water for flushing a casualty. Tepid water is defined as being within the range of 60 to 100 degrees Fahrenheit. The requirement of tepid water is to ensure that workers can rinse under the shower for the full duration of 15 minutes without suffering thermal shock, which assists decontamination and prevents hypothermia.
Storing the tepid water at the lower range of 60 to 68 degree Fahrenheit reduces the growth of harmful bacteria in the water tank. The effectiveness of a safety shower providing tepid water for treating chemical burns is vastly improved compared to one providing cold water, as not only does the cold water discourage casualties from using the shower, but it also closes pores on the skin, which can trap contaminants and hamper any attempt to wash it off.
Water that is too cold can exacerbate the problem because the user could go into thermal shock. In a recent conversation at PowerGen with a plant operator, I learned about his experience with chemical burns. He stated that he had to step in and out of the shower to withstand the cold water. Chemicals left on his body caused tissue damage; the burns would have been minimized if the water had been tepid. On the other hand, hot water can cause scalding and can intensify the damage caused by certain chemicals.
This brought about demands by the petrochemical industry for emergency decontamination units to provide water at the correct temperature. Some manufacturers of emergency showers have gone one step further to guarantee up to 20 minutes of tepid water, notwithstanding the extreme climatic conditions in which safety showers are sited.
However, in situations where the contaminant is a burn-inducing chemical, some may argue the drenching time should be extended to a minimum of 20 and even 30 minutes of tepid water using a tank shower. A major benefit of a tank shower for providing tepid water instead of a plumbed-in, tempered-water model is that the tank shower will guarantee 15 minutes water is always available even if the water main fails, which prevents a plumbed-in model from providing any water and therefore renders the shower out of action. This will prevent production processes from taking place.
Normally, a 15-minute time period would be a suitable length to wash most contamination off clothing. However, when the tepid water turns to freezing, workers can be tempted to step out of the shower, believing their clothing to be free of the hazardous substance. Unfortunately chemicals can react when it comes into contact with water (such as caustic soda, which turns to a slimy consistency and can be difficult to wash off). This can result in contaminants remaining on clothing even after a 15-minute flush; which is why it is imperative for an operative to strip off all clothing for full flushing to be effective.
When installing an emergency shower facility, it is vital to assess risk on an individual basis. This can include a risk assessment not only against the control of hazardous substances, but also against climatic conditions, the surrounding environment, and the workforce, including lone workers and the mix of male/female employees, for example.
We advise that any organization looking to upgrade or install new emergency shower or eyewash at their facility to carry out a comprehensive risk assessment. Important areas that need to be considered include:
1. Ensure the quality and performance of the unit are suitable for your needs and the needs of your personnel and meet the current ANSI standards. Shortcuts can cost more in the long run and lead to legal action by harmed employees.
2. Check that the water supply pipework is capable of delivering 20 gpm.
3. On all units, check that the correct temperature is being maintained, this being under 77 and above 60 degrees Fahrenheit. If the temperature is too hot, it can increase the harmful effects of chemicals on the skin. Too cold, and it can cause hypothermia, plus the correct drenching time may be insufficient because the user will not be able to stay under cold water for the recommended 15 minutes, let alone the 30 minutes required for certain chemicals.
4. Check on the disposal of the contaminated water. Residual water should be disposed of carefully to ensure contaminated water is not allowed to enter the water main. Also any excess water collected on the floor during testing or after an emergency can be a hazard, creating a slippery or icy surface.
5. Measure employees’ sizes and check the area you want to designate for a shower unit to ascertain whether it will provide a suitably sized emergency facility. With the average physical size of people in North America increasing, there needs to be adequate room to accommodate the necessary movement when using the shower. Struggling to quickly strip off contaminated clothing in a restricted area is very difficult, uncomfortable, and can exacerbate the problem, especially with part of the space occupied by an eyewash unit. The recommended ANSI standard of a 34 inch (86.4 cm) cubicle diameter is adequate but not ideal. Increasing the size of a decontamination unit it will provide better protection.
6. Check the pipe work feeding the shower. With a changing climate, exposed pipe work that survives a normal winter season is no longer adequate and will not meet the recommended standards. This will mean either relocating the shower unit or insulating and heat tracing the pipe work.
7. Are curtains or doors needed for modesty? Not providing a modest safety shower can cause employees to hesitate to appropriately wash down. In emergency situations, time is critical.
Complying with ANSI requirements puts the safety of your employees first while protecting employers from governmental enforcement and legal actions. The cost to update or install the correct safety equipment pales in comparison to the cost of a citation and, more importantly, an employee’s life. The bottom line is that it only makes sense to put safety first by providing safety equipment that will perform in the critical few moments when it is used.
This article originally appeared in the September 2012 issue of Occupational Health & Safety.