Responding is Ryan Corcoran, director, Bullhead Safety, Atlanta.

Fogging can disrupt a person’s ability to perform work tasks safely. This observation has led to the development of various anti-fog technologies designed to reduce or eliminate fogging of safety glasses. These technologies include basic hydrophobic and more complex hydrophilic coatings.

Basic hydrophobic anti-fog

Hydrophobic (adverse to water) coatings are the predominant anti-fog coating used in North America. The soap-based coating creates a water-resistant barrier that stops water from adhering to the lens. The coating repels water by forming it into beads that stream down the lenses to provide clear vision and prevent fogging.

The coating is versatile and effective in a wide range of environments, including rainy, cold, wet, humid and variable temperature conditions. The application process is simple and cost effective.

The drawback of the soap-based composition of the coating is it’s susceptible to washing off over time.

In addition – in extreme fogging environments – hydrophobic coatings may fall short, leading to visibility challenges and potential compliance issues for workers.

Hydrophilic ANSI/ISEA-rated anti-fog

ANSI/ISEA Z87.1-2020 anti-fog-rated glasses – known for their durability and adaptability – incorporate nanotechnology and natural proteins. The nanosized particles create a microscopic barrier on the surface of the lens, preventing the condensation of water vapor into visible fog.

The hydrophilic (attracted to water) coating prevents fogging by attracting water and creating a thin layer of moisture that can absorb and dissipate fog and heat. Along with its anti-fog properties, the coating improves the lens’ resistance to smudges and scratches, making it more durable and easy to clean.

The hydrophilic coating bonds into the pores of the polycarbonate lens, making a virtually permanent coating. Further, the hydrophilic coating differs from hydrophobic in that it isn’t soap-based. This characteristic means the coating won’t wash off like hydrophobic solutions.

Safety glasses that bear an “X” marking on the lens have gone through a full battery of tests as outlined in the ANSI/ISEA Z87.1-2020 anti-fog testing requirements. The testing includes resistance to abrasion, adhesion and durability under various environmental conditions.

One of the notable advantages of ANSI/ISEA Z87.1-2020 anti-fog-rated glasses is their ability to maintain clarity in diverse and extreme environmental conditions. Whether facing extreme/variable temperatures, humidity or wet conditions, this technology ensures wearers can rely on their safety glasses without the hazard of fog.

Both ANSI/ISEA Z87.1-2020 anti-fog-rated hydrophilic and basic hydrophobic anti-fog technologies offer effective solutions for preventing safety glasses from fogging. The choice between the two depends on individual preferences, budget, need for longevity, specific use cases and environmental conditions. ANSI-rated hydrophilic stands out for its permanency, robustness and adaptability, while basic hydrophobic anti-fog appeals to those seeking a more cost-effective way to achieve clear vision in fog-prone environments. Ultimately, the decision should align with the wearer’s priorities, ensuring clear vision and enhanced safety in a variety of work environments.

Editor's note: This article represents the independent views of the author and should not be considered a National Safety Council endorsement.