We all have events in our professional lives that shape the way we look at issues. For us, one of these was an accident where a researcher was unloading a cart of chemicals onto a bench. He had two large bottles of glacial acetic acid in his hands. He tapped the side of one against the edge of the bench and it broke. The bottom fell out of the bottle, spilling the contents on his legs and feet. He then slipped and fell down in the pool of acid and broke the second bottle. Much of the lower half of his body was now soaked with acid. A lab mate tried to help. She got him over to the sink and began trying to splash water on him. There was a lot of noise and yelling, which drew a researcher from an adjoining lab to see what was going on. He quickly sized up the situation, assumed control, and pulled the victim into the hall to the emergency shower, where he initiated the appropriate decontamination process. It was estimated that this onset of decontamination occurred several minutes into the exposure event. The victim was hospitalized with chemical burns. The tragedy of this incident is that there was a safety shower immediately outside the lab in the hallway and decontamination could have been initiated in just seconds.
Accidents do happen and personal protective equipment and engineering controls do sometimes fail. This is when we need emergency procedures and equipment to minimize the effects of accidental exposure to chemicals. For those in the laboratory, emergency showers and eyewash stations provide the means for this immediate decontamination. With this article we want to bring to your attention four very important take-home messages:
Speed to Action: Time to decontamination is critical in minimizing injury.
Duration: Rinse affected area for a sufficiently long time.
Access: Maintain free and unimpeded access to emergency equipment.
Equipment: Use appropriate and maintained equipment.
Speed to Action
OSHA considers emergency showers and eyewashes under their section on Medical Services and First Aid. They specifically state in the regulation 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 is important to note the phrase “for immediate use” in the standard. From a practical standpoint, regulations aside, this is critical. As with our case above, delaying treatment even for a few seconds or minutes may greatly increase the severity of injury. Any contaminated clothing should be removed under the shower to remove the chemical from prolonged intimate contact with the skin.
One report on chemical burns over a ten-year study period showed that effective first aid (rinsing with copious quantities of water within three minutes of injury) greatly improved the outcome for the patients, including a lower incidence of third degree burns, shortened hospital stays, and fewer delayed complications.1 The shorter the time the chemical spent on the skin or in the eye, the less damage occurred. With splashes to the eye, quick and effective action can mean the difference between having functional vision or not.
A different study reviewed the histories of more than 100 patients whose eyes were severely injured by chemical exposure.2 Patients that received immediate rinsing required fewer operations, had shorter hospital stays, and had significantly better vision than those where treatment was delayed. In this study, however, even patients who received immediate first aid showed severe damage. The author of the study believes this may have been due to inadequate irrigation time.
Duration of Decontamination
The American National Standards Institute (ANSI) recommends that the affected body part be flushed immediately and thoroughly for at least 15 minutes using a large volume of clean water under low pressure. Next time you are in a meeting that does not require your undivided attention, note the time and mark how long 15 minutes really is. It can be a lot longer than it feels. Eye contact with strong acids or alkalis may require an even longer lavage time to prevent injury, as the chemicals react with the eye tissue. In these cases, flushing may be continued en route to the doctor. We always recommend medical evaluation with any hazardous material exposure to the eye.
To be effective, the equipment has to be accessible. ANSI recommends that a person be able to reach the equipment in no more than ten seconds. All too often on workplace surveys we see that the immediate access to the safety shower or eyewash is blocked or impeded. This might be caused by a cart parked under the shower, boxes stored on the floor in front of it, or items placed in the eyewash sink (a handy place to put a box or two of gloves, no?). Now imagine some corrosive splashed in your face and trying to get there with your eyes clamped tightly closed. It’s tough enough to do without added obstacles in the way or having to clear the area as you are being burned by the corrosive. To counteract this, we recommend delimiting a no-storage zone with tape or markings on the floor to help ensure that the area immediately around the shower is free and open.
OSHA, in its standard, mentions, but does not specifically define “suitable facilities”; however, the ANSI does through their Standard Z358.1-2004 “Emergency Eyewash and Shower Equipment.” This is the generally accepted standard for emergency showers and eyewashes in the workplace.
Both safety showers and eyewash stations must deliver clean, tepid water, have a single control to activate, and continue to operate in a hands-free fashion for at least 15 minutes. ANSI-compliant eyewash stations are designed to deliver fluid to both eyes simultaneously. The water should be low velocity so as not to injure the eyes. The station needs to be operated in a hands free fashion so the exposed individual can use hands to help hold the eyes open for effective irrigation.
You may find drench hoses in many labs by the sink. (It is important to note that having a drench hose usually does not remove the need for showers/stations.) Some hoses have a single spout; some are actually binocular and are designed to meet the ANSI standard for eyewashes. We generally like to see these in labs, as people are more apt to adequately rinse a small splash to an extremity or to the eyes with this set-up than with the full shower or station that might drain onto the floor. One additional positive aspect of a drench hose is they get used for other lab activities on a frequent basis and so the water in them is regularly flushed. A testing and flushing program for eyewashes and safety showers must be part of a good safety program, but is beyond the scope of this article.
What about those little eyewash bottles? These are intended to deliver flushing fluid immediately, but cannot meet the 15 minute or the binocular requirement of an eyewash station that meets ANSI standards. They can be used in some particular situations, such as while transporting a victim to the permanent eyewash station or medical facility. The expiration date of the fluid must be monitored.
As we so often say, know your materials and your equipment. Make sure you could find your safety shower and eyewash with your eyes closed if need be; that is, know where it is and keep the path free and clear. Should the need arise for use, do so rapidly and for adequate duration. Do not let modesty cloud your professional judgment. We have never heard of anyone criticized for removing contaminated clothing under a shower, but have often heard lamenting over the burns received from an inadequate response. Until next time, stay healthy and safe!
1. Moran, K.D. "Chemical Burns: A Ten-year Experience." American Surgery. Vol. 53 (1987). p. 652-653
2. Kuckelkorn, R., et al. "Poor Prognosis of Severe Chemical and Thermal Eye Burns: The Need for Adequate Emergency Care and Primary Prevention." International Archives of Occupational and Environmental Health. Vol. 67, no. 4 (1995). p. 281-284.