Even in a pandemic, certain professions must press on. If you work in an emergency services or infrastructure role that requires the use of safety equipment, you may be wondering, “how do I prevent transmission of germs via my safety equipment?”
In a recent study conducted by experts from the US Centers for Disease Control and Prevention (CDC), NIH, UCLA, and Princeton University, investigators found that SARS-CoV-2 is detectable in aerosols for up to 3 hours, on copper up to 4 hours, up to 24 hours on cardboard, and up to 3 days on plastic and stainless steel.
Cleaning surfaces and equipment that are regularly touched or that may be exposed to germs can help reduce the spread. Recommendations from the CDC are to include cleaning AND disinfecting frequently touched surfaces first with detergent or soap and water, and then following this cleaning with disinfectant.
“choose a disinfectant appropriate for the material”
Most common EPA-registered household disinfectants will work, so choose a disinfectant appropriate for the material you are cleaning. If necessary, you may secure MSDS sheets from the cleaning solution manufacturer to identify what materials are damaged by that solution.
Some of the options include
- a dilute bleach solution (1/3rd cup bleach per gallon of water OR 4 teaspoons bleach per quart of water)
- A 70% alcohol solution
“bleach is known to weaken the fiber structure”
With any chemical compound there are several factors that will influence whether or not it will damage a given material. Of primary importance, of course, is simply the relationship between that compound and the material being cleaned. With this as a foundational context, actual damage can also be affected by concentration, duration of exposure, and temperature.
Although bleach is known to weaken the fiber structure of materials such as nylon and polyester, PMI has found that a single treatment of a mixture of up to 1 part household bleach (with active ingredient of Sodium hypochlorite at 5.25% concentration) with 9 parts room temperature tap water and a 10min or less exposure time, immediately followed by a thorough rinse of room temperature water will not cause appreciable harm to nylon or polyester ropes.
Likewise, plain rubbing alcohol can be a good cleaning agent that is generally mild enough to not damage or melt rope fibers, but again the alcohol solution must be thoroughly rinsed out of the material promptly so it doesn’t damage the material. At high temperatures and under extended exposure conditions, nylon is known to be damaged by isopropyl alcohol.
“recommended method will not cause appreciable harm”
Keep in mind that the cumulative effects of frequent or repeated decontamination using these compounds has not been thoroughly studied, and should be undertaken with care. Given the understanding that both bleach and alcohol can weaken the fiber structure of a rope, it only stands to reason that repeated treatments are likely to weaken the fiber structure even more. Although PMI’s testing suggests that a single disinfection using the recommended method will not cause appreciable harm to nylon or polyester ropes, if this process is repeated multiple times the damage will inevitably become appreciable, and this damage is not necessarily detectable through visual inspection.
Use and care of life safety products should not be undertaken lightly, and it can be difficult to make subjective decisions about the strength of rope and equipment without actually testing it to failure. The prudent course of action is to discard any rope about which there is any doubt.
For more information on chemical compatibility with nylon, visit calpaclab.com