Whenever Jacob, the histology lab employee, poured the waste chemicals into the large barrel in the lab’s Central Accumulation Area, he always wore a face shield as well as a lab coat and gloves. He felt he was prepared because he knew this task had a high risk of splashing and potential chemical exposure. When Jacob began to tip the waste jug toward the barrel, it slipped out of his hands and bounced against the funnel splashing a mixture of xylene and other stains onto his shoulders and head. Although Jacob’s eyes were protected, he knew enough chemical had splashed onto his body that he needed to use the emergency shower in the department.
A co-worker came over when she saw the incident. She helped Jacob get his lab coat and other PPE off, and she activated the safety shower. Lab staff tested the shower weekly as required, but they used a large bucket and only activated the shower for a few seconds. As Jacob was rinsing off, the small drain under the shower was unable to drain all of the large amounts of water being poured out by the shower head. The laboratory quickly began to flood. Cardboard boxes on the floor quickly became soaked. Staff began to worry about electric shock because of the multi-plug adaptors resting on the floor. The manager became upset as he knew the floor tiles would now need to be replaced- he knew water would eventually cause them to separate and lift off the floor. Water began to seep through the walls of the lab into the adjacent carpeted offices. The manager knew there could now be future expensive mold abatement needed. As the waters kept rising, the lab team decided to turn off the shower even though it had only been on for three minutes. They took Jacob to the emergency department for treatment and further decontamination.
The use of laboratory safety showers in splash incidents is not common, but it does happen, and the lab needs to be prepared for such an event. That preparation not only involves testing and training on equipment use, but also in making sure the physical space is ready for a potential deluge of water that can pour down into the department for potentially up to fifteen minutes.
One reason safety specialists and some regulatory agencies require that items in the lab not be stored directly on the floor is so they will not be damaged in the event of a departmental flood. The use of a shower is just one way water can get onto the floor. A leak of the deionized water system or a drain failure can also cause flooding. It is generally acceptable to store plastic items (waste bins, etc.) on the floor since they cannot be damaged by water. Cardboard, computer hard drives, and other like items should be stored on palettes or shelves. Securing electrical wires and raising multi-plug adaptors off of the floor is also a best practice.
The best laboratory flooring is monolithic, like a sheet vinyl that has few seams. It should bend up to the walls to create a coved base that is integral with the floor. This design (recommended by the CDC and CLSI) keeps liquids from going under tiles or through walls which will create more problems down the road.
Floor drains where safety showers exist are not required, and many labs have showers where there is no drain at all. Remember that in a typical situation where a shower would be used, hazardous chemicals are involved. Any hazardous waste that might go into the sanitary sewer should be routed through a neutralization station or into a hazardous waste collection tank. The ANSI requirements for a safety shower include the ability to deliver 20 gallons of water per minute for 15-20 minutes. That’s a total of 400 gallons. The requirements also state that the water pattern must be at least 20” in diameter and 60” above the floor. Therefore, a majority of the water will not even travel to the drain. It will go to the lowest point of the floor in the department. The bottom line is, if the safety shower must be used, a flood should be expected.
In order for the lab to be prepared for using the shower, materials should be on hand that will help mitigate flooding. Those materials may include large volume spill kits with booms or dikes that are capable of holding water back. Staff should be trained how to use these materials as spill training is provided, and drills should be conducted so they can use the supplies comfortably.
Is your lab designed for safety in the event of a hazardous material spill or exposure? Is the department set up to handle a flood situation, and can staff identify the steps to take to respond efficiently and safely? Take a look around your lab today, and make any necessary corrections so that all will be ready should a laboratory flood occur for any reason.