Page 22 - OHS, February/March 2025

P P E : P R O T E C T I V E A P P A R E L
The Science Behind High-Visibility Protective Fabrics
Workers in high-risk work environments need to feel confi dent their fl ame-resistant
clothing will also help them be seen by others.
BY STEVE LUCAS
20,000 line workers descended upon the Western
When Hurricane Helene hit the Carolinas last, nearly
North Carolina and Upstate South Carolina re-
gions to support the recovery and power restora-
tion eff orts. In an all-hands-on-deck situation, these crews worked
around-the-clock to restore power to the millions of customers
across the Carolinas who were forced to live off -the-grid, some go-
ing weeks without power.
Th is work wasn’t typical 9-to-5 work either. With shift s that
could last up to 16, 18 or even 24 hours a day, the environments
these workers had to navigate were treacherous. Wading through
mud, navigating fallen trees and desolate roadways and working in
the pitch black put an additional emphasis on the need for high-
performance protective apparel. In this situation, these line work-
ers needed to trust the fl ame-resistant clothing they wore could
handle whatever the terrain threw at them.
Incidents like this force workers in high-risk professions, such
as utilities and oil and gas, to think about how the apparel they
wear on-the-job is designed and manufactured — and trust they’re
working with suppliers who are bringing the most innovative, cut-
ting-edge science to the table.
Take high-visibility apparel for example, a quick Google search
for “hi-vis clothes for line workers” returns dozens of search results
— but few go in-depth on what it takes to make FR clothes truly
hi-vis. Aft er all, anyone can dye a cotton t-shirt yellow and say it’s
ready to help protect you at night, in bad weather or under any
other low-visibility situation. Th e truth is that it takes a reliable
manufacturing process, proven FR technology, a perfect dyeing
process, and a team with decades of experience developing protec-
tive fabrics for these exact situations.
Understanding the Nuance of Hi-Vis Materials
To the naked eye, it’s impossible to look at a yellow shirt or vest
and tell if it’s high-visibility. Not just any bright yellow or bright
orange shirt can be considered high-visibility; it comes down to
the brightness, or the fl uorescence in the garment, not the color.
Th e easiest way to think about it is like this: take a white T-shirt.
Th en, put it under a black light and watch as it illuminates. It gives
you a bright white that almost looks like it’s glowing or that it has
been hit with a highlighter. You’re looking at the same white t-shirt,
but your eye looks at it in a diff erent way under a diff erent light. So,
you see it shining back as a fl uorescent light in the darkness. Again,
it’s the same color but your eye is picking up the luminance.
Th at’s how you can think about hi-vis garments. When light
hits it in the dark, will it shine that bright light, will it illuminate?
Sourcing and Standards
If you’re purchasing hi-vis garments for your workforce you want
to look for fabrics that have been certifi ed to the ANSI 107 stan-
dard. Th is standard provides guidelines for the design, perfor-
mance, and use of high-visibility safety apparel (HVSA) across a
variety of working environments. Any credible manufacturer will
have these certifi cations readily available for their materials.
Th ere are various requirements for ANSI 107 but the more
challenging requirements to meet for a product that contains cot-
ton is the colorfastness tests. Th e fabric is submitted to a Xenon
light that simulates the potential fading caused by the sun. You
must get the color to stay inside a specifi c region of color space and
maintain its brightness, essentially without any fading.
When sourcing these types of materials, pay close attention to
the history and experience of the manufacturer. An infl ux of copycat
fabrics into the market makes it critical that you look at the supplier’s
track record with testing, certifi cation and meeting standards. Any
reliable manufacturer will be able to provide proof of testing and can
answer any questions about the supply chain of the materials.
How Flame Resistance Impacts Development
Color space is an important concept to understand when it comes to
high-visibility materials. When you think about a color space, think
about an American football. Every color you see falls within a three-
dimensional space, or this football. What the ANSI says is that your
yellow, in this case, must fall within a very specifi c football and if it
doesn’t it’s not ANSI 107. But the trick is that it’s not just the color
with this standard, it’s the brightness. Manufacturers can get a fl ame-
resistant fabric into the right yellow football; the hard part is making
sure it’s bright enough. Which is a totally diff erent football.
Th e challenge in the past with cottons has been the propensity
to fade with this xenon light test that ANSI runs. Basically, if you’re
wearing this shirt out in the sun every day for a month, will the
brightness lose its luster?
Wash durability is another important test and one that can
cause hiccups in the development stage. Th e fabric is washed mul-
tiple times and reevaluated for color space and luminescence. Th e
standard only requires you to maintain that brightness aft er fi ve
washes, but there are available fabrics that have been shown to last
at least 100 washes and still maintain their color and brightness.
A Final Safety Note
While science plays a major role in getting high-visibility garments
into the fi eld, the most important thing is that workers want to
wear them. Adding multiple layers of PPE can decrease workers
range of motion and comfort level, aff ecting their mindset against
the role it plays in keeping them safe on the job. To that end, ask
suppliers about the textile technology available to limit the layers
of fabric needed to address visibility issues, and prioritize fabric
that considers the feel, movement and weight of the garment.
Steve Lucas is development manager (protective fabrics) for Mil-
liken & Company.
20 Occupational Health & Safety | FEBRUARY/MARCH 2025 www.ohsonline.com