FRC Safety During COVID-19: Impact of Residual Bleach Spray on Flame Resistance

In these uncertain times, you can rely on Tyndale to provide the latest information on arc rated (AR) / flame resistant (FR) clothing safety during COVID-19. In the post and video below, we talk about the potential impact of residual bleach spray on flame resistance. For additional information on AR / FR safety during COVID-19, please click here.

First and foremost, liquid chlorine bleach is prohibited from use on all flame resistant and arc rated fabrics and apparel in common use in the USA today. Neither Tyndale nor fabric manufacturers recommend or endorse using liquid chlorine bleach on arc rated and/or flame resistant (FR) clothing. However, we understand that during crisis situations, as with COVID-19, hard and fast rules may occasionally become guidelines as a result of an immediate need or greater perceived threat.

That said, we’ve received a number of questions about the effects of dilute bleach solutions being used to disinfect trucks, tools, and other things, by application through a plastic spray bottle or plant mister. The main question is, what if the solution accidently drips or spills on AR / FR apparel? Does it have an impact on flame resistant properties?

To answer this, we opened our ASTM D6413 lab to run vertical flame tests. Scott Margolin, Tyndale’s Vice President of Technical shares those results in the video below:


Watch our VP of Technical, Scott Margolin share an important safety alert on the impact of residual bleach spray on flame resistance.

Watch the video by clicking on the preview to the left.


It’s important to note that while we didn’t test every variable, we were able to test the three most basic exposure routes: one pump of the trigger on mist setting, three pumps mist, and a direct spill of several ounces. We intentionally used twice the CDC recommended concentration (2/3 cup per gallon rather than 1/3 cup) to establish an extra margin of safety. The samples were allowed to dry and were then tested; all three passed vertical flame.

Passing means, they did not continue to burn, did not have altered afterflame, and had char lengths that passed the test. They retained their flame resistant properties despite the bleach application they sustained. Based on this limited and preliminary research, evidence shows that one exposure of a CDC COVID-19 recommended dilute bleach solution on a new AR / FR garment will not materially degrade the garment’s flame resistant properties.

As Scott mentions, Tyndale does not endorse using liquid chlorine bleach, diluted or not on FRC; we never-the-less honor your right to know how to use it safely in these uncertain times. Best practice is to never handle bleach or dilute bleach solutions while wearing FRC. If you have to use a dilute bleach solution and you’re wearing PPE, best practice is to: Ask someone else, who is not wearing FRC, to mix and spray the solution.

  1. If no one else is available, change out of your FRC before spraying the solution. Then, change back into your FRC once the solution is applied.
  2. If that’s not an option, cover your FRC before spraying the solution.

During this time of quarantine and social distancing, none of the above may be viable options for you. As a result, you may need to spray the diluted bleach solution yourself, while wearing AR / FR clothing. If this is the case, you should mark the inside of the FR clothing you’re wearing with a permanent marker so you know to discard it after COVID-19 is no longer a threat. And, know that between our testing and the IEEE paper Scott references in the video, should give you confidence that a single mishap will not destroy your FRC.

If you have additional questions, please reach out to us or visit our COVID-19 resource page on the website. Stay safe and healthy.

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