Chemical Engineering March 2017 - 59

ties: hydrophilic and hydrophobic.
2. Be sure the manufacturer's batch
creation and application processes
are rigorously monitored
and tested to ensure the highest
standard of anti-fog consistency
and longevity.
3. Be sure the lens coating application
process delivers smooth,
consistent results on every pair of
eyewear to support exceptional,
distortion-free optics.
4. Look for manufacturers using an
intense curing process to permanently
adhere the coating to the lens.
Only permanent coatings will deliver
consistent fog-free performance,
even after frequent wear, wiping and
washings.
FIGURE 2. Lens coatings that provide both hydrophilic and hydrophobic properties (right side) are much
more effective against fogging compared to traditional anti-fog coatings (left side)
It's important to note there is no
national standard for measuring,
or requirement for delivering effective
anti-fog performance on safety
eyewear in North America. Europe's
stringent EN166 and EN 168 safety
eyewear standards, however, do
incorporate the only global test
method and certification for resistance
to fogging of oculars. The European
test requires the submersion
of lenses into water for up to two
hydrophilic properties that absorb
moisture into the lens, and hydrophobic
properties that spread excess
condensation in a clear film over
the lens surface and ultimately shed
moisture off the lens.
Applying dual-action anti-fog coating
so it goes on and stays on permanently
- even after repeated
washings and wiping - is key to the
coating's durability. Look for manufacturers
that bond anti-fog agents perToday's
advanced lens coating technologies actively
manipulate moisture through surface-acting agents,
chemicals designed to move to the lens surface as needed
to prevent fogging.
hours, followed by direct, ongoing
exposure to fog from test apparatus.
Performance is measured in
the number of seconds before the
lenses fog and disrupt vision. You
will find lenses meeting or exceeding
these European standards to be
superior to those that do not.
Anti-fog technology
Today's advanced lens coating technologies
actively manipulate moisture
through surface-acting agents,
chemicals designed to move to the
lens surface as needed to prevent
fogging. The most reliable coatings
employ dual-action properties:
manently to the lens, and those that
rely on controlled application methods
and vigorous product monitoring
that ensure anti-fog coatings absorb,
then spread and shed, the greatest
amount of moisture consistently over
the longest possible time. A long-lasting,
consistently fog-free safety lens is
one your workers can wear shift after
shift with the clear, fog-free view vital
to performing their tasks.
Selecting anti-fog eyewear
The following are six tips for selecting
effective anti-fog eyewear:
1. Look for anti-fog coatings that employ
dynamic, dual-action properCHEMICAL
ENGINEERING WWW.CHEMENGONLINE.COM
MARCH 2017
5. Look for anti-fog coatings on a
wide
range
of
safety
eyewear
types, from goggles and sealed
eyewear to spectacles, as well as
lens tints, to provide anti-fog protection
to workers across a wide
variety of applications.
6. Only eyewear that meets or exceeds
Europe's stringent EN166 and EN
168 safety standards have been
tested and proven in their effective
resistance to fogging of oculars. n
Edited by Gerald Ondrey
References
1. Prevent Blindness, Eye Safety at Work, Chicago, Ill., www.
preventblindness.org/eye-safety-work
2. U.S. Bureau of Labor Statistics, Nonfatal Occupational
Injuries and Illness Requiring Days Away from Work,
2013, www.bls.gov/news.release/pdf/osh2.pdf
3 National Institute for Occupational Safety and Health,
Washington, D.C.,
Author
Phil Johnson is a Fellow at Honeywell
Safety and Productivity Solutions
(10 Thurber Blvd., Smithfield,
R.I.
02917;
Phone:
2309; Email:
401-757phil.johnson2@
honeywell.com).
He has more than
40 years of experience in the safety
eyewear and consumer eyewear
sectors. During his 28 years with
Honeywell's Uvex safety eyewear
business, he has led research and development and quality
assurance operations. Prior to becoming Fellow in
2011, he was director of technology. Johnson's expertise
in materials technology spans plastics and coatings, optics,
and dye technologies for radiation protection. He
contributes to product development for eye, face and
head protectors used in industrial and military applications,
and is active in global regulatory compliance activities.
He is an active member of national eyewear standards
development committees, is widely published, and
holds several design patents. Johnson holds a B.S. and
an M.S. in management science from Worcester Polytechnic
Institute.
59

http://www.preventblindness.org/eye-safety-work http://www.bls.gov/news.release/pdf/osh2.pdf http://WWW.CHEMENGONLINE.COM

Chemical Engineering March 2017

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