The Three Classes of Hi-Viz

Welcome back, let’s Build Smart & Build Safe! High-visibility (Hi-Viz) clothing is often the only thing standing between a ground worker and a multi-ton piece of moving equipment. Many companies treat safety vests as a generic "one-size-fits-all" requirement, but the American National Standard for High-Visibility Safety Apparel (ANSI/ISEA 107) defines specific classes based on the risk level of the work environment.

Being "bright" is not enough; you must be visible in a way that allows an operator to recognize you as a human being and react in time.

Understanding the ANSI Classes

The class of your garment is determined by the amount of background material (fluorescent fabric) and retro-reflective material (the shiny tape) it contains.

• Class 1 (Low Risk): These are designed for environments where traffic does not exceed 25 mph and workers are well-separated from vehicles. In modern heavy construction, Class 1 is rarely sufficient.

• Class 2 (Moderate Risk): This is the standard for most construction sites. It requires more reflective tape and background material than Class 1. It is intended for workers near traffic moving between 25 and 50 mph, or in environments where complex backgrounds make it harder to see personnel.

• Class 3 (High Risk): This provides the highest level of visibility and is mandatory for high-speed environments (over 50 mph) or nighttime operations. Class 3 garments must have sleeves with reflective material to define the "human silhouette," allowing operators to distinguish a worker from a stationary cone or barrel at a distance.

The "Human Form" Factor

The primary goal of the Class 3 standard is "biomotion" recognition. When reflective tape is placed on the arms and legs, the brain of an equipment operator recognizes the movement of those limbs as a person much faster than it recognizes a solid block of color.

• Recognition Distance: A Class 3 garment can increase the distance at which an operator recognizes a human from 300 feet to over 1,200 feet.

• 360-Degree Visibility: Regardless of the class, the garment must provide 360-degree visibility. If a vest is worn open or is covered by a tool belt, its safety rating is effectively voided.

Implementation: The Site Visibility Audit

Before heading out to the line of fire today:

1. Check the Tag: Ensure your vest meets the ANSI class required for your specific task (usually Class 2 or 3).

2. Evaluate the Speed: If you are working near live traffic or heavy machinery moving at high speeds, verify you have the sleeve coverage required for Class 3.

3. Inspect for Obstructions: Ensure tool pouches, harness straps, or clip-on radios are not obscuring more than a small fraction of the reflective tape.

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-The Safety Man