Laundering Myths: Is Lint Contamination Really a Threat to FR Clothing?

This blog post is the second of a 3-part series. Click here to read the previous post on How to Wash FR Clothing & Useful Wear Life. Coming up, we will also cover Using Fabric Softener with Your FRC.
We’ve all experienced having lint balls on our clothing or in our pockets. During normal wear and use, fabric fibers can collect on the surface of your garments and typically come off during the wash process. Most fabrics can also experience pilling, or when short fibers break away and cling to the surface of a garment leaving little fuzzy balls.
To protect their business, industrial laundries speculate that FR products washed with non-FR garments could become contaminated with non-FR lint which would support combustion. While laundering FR and non-FR garments together may result in appearance degradation and/or lint transfer for some FR fabrics, it is unlikely to result in reduced flame resistance (1). In fact, repeated laboratory testing has proven that this is unsupported speculation.
Lint Impregnated Arc Test
As seen in the series of images above, identical 7 oz. Indura® UltraSoft® light blue button down shirts were used in this lint contamination test (see left image). The non-contaminated shirt was washed alone, using standard detergent. The contaminated shirt was washed with two large navy blue 100% cotton terrycloth towels. Both shirts are exposed to simultaneous electric arc flash (see middle image), demonstrating that the lint contaminated shirt showed no noticeable after-flame (see image on right). Click here to watch the actual test video.
Conclusion: Non-FR lint on a flame resistant garment provides no measurable protective degradation and no sign of persistent after-flaming.
The best advice is to sort your laundry and wash like garments together. Use soft water or detergent specifically designed for hard water. Hard water (greater than 7 grains per gallon of hardness) can leave residue on fabrics that may mask flame resistance (1). The biggest risk is not laundering your FR garments at all!
Tyndale will work with your company to analyze costs and benefits of different laundering solutions. In our experience, home laundering ensures longer garment life and greater convenience. However, industrial laundering may be the best option for workers whose garments are severely soiled, or for those exposed to dangerous chemicals. Each company has unique laundering needs, and Tyndale will work with you no matter what your laundering needs are (2).
For more information on Care and Maintenance of FR Clothing, please see ASTM F2757, Standard Guide for Home Laundering Care and Maintenance of Flame, Thermal and Arc Resistant Clothing.
References for this post were accessed September 2013:
(1) ASTM F2757-09, Standard Guide for Home Laundering Care and Maintenance of Flame, Thermal and Arc Resistant Clothing