The Original Bug Shirt®: Is Hi-Viz right for me?
What should I look for in High-Visibility Safety Apparel (HVSA)?
The following information is extracted from the Canadian Centre for Occupational Health and Safety web site.
Large, bright garments are more visible than small ones. Coverage all around the body (360° full body coverage) provides better visibility in all viewing directions.
Stripes of colours that contrast (have a distinct colour difference) with the background material to provide good visibility. Stripes on the arms and legs can provide visual clues about the motion of the person wearing the garment.
When background material is bright-coloured or fluorescent material, it is intended to be highly visible, but is not intended to provide retroreflective performance.
Daylight – Bright colours are more visible than dull colours under daylight conditions (e.g. fluorescent materials are suitable for daylight).
Low light conditions – Fluorescent colours are more effective than bright colours under low light (e.g. dawn and dusk). Under these conditions, reflective materials are also suggested.
Dark conditions/worksites – Greater retroreflectivity provides greater visibility under low light conditions. Retroreflective materials provide high-visibility conditions and are preferred over bright colours. Fluorescent materials are ineffective at night and less visible than white fabrics.
What is the difference between fluorescent and retroreflective materials?
Fluorescent material takes a portion of invisible ultraviolet light from sunlight, and through special pigments, sends it back to the viewer as more visible light. This material only functions where there is a source of natural sunlight. Fluorescent material will appear brighter than the same coloured non-fluorescent material, especially under low natural light (e.g., cloud cover, fog, dusk, dawn, etc.). This property offers daytime visibility enhancement not present with other colours. These materials enhance daytime visibility, especially at dawn and dusk. Fluorescent colours provide the greatest contrast against most backgrounds.
Retroreflective material is created to return light in the direction of the light’s source. This property will let a driver see the light being reflected from the retroreflective material on a person’s garment (as long as the person is standing in the light’s beam). Retroreflective materials are most effective under low-light level conditions. While retroreflective materials can still reflect in the daylight, there is little difference between the light reflected from the garment’s material and the surrounding environment. This lack of contrast makes retroreflective materials ineffective for enhanced visibility during (sunny) daytime conditions.
To comply with the CSA Standard, the HVSA should meet the following criteria for the stripes/bands:
A waist-level horizontal stripe/band that goes completely around the HVSA.
Two vertical stripes on the front passing over the shoulders and down to the waist.
A symmetric “X” on the back extending from the shoulders to the waist.
For Class 3 apparel, stripes/bands encircling both arms and both legs are added.
For all classes, the CSA Z96-15 High-Visibility Safety Apparel Standard specifies both the colour of the background and the stripes/bands. Class 1 (e.g., harness style) must have a minimum of 0.14 metres squared of background material. Background material should be one of fluorescent yellow-green, fluorescent orange-red or fluorescent red; or one of bright yellow-green, or bright orange-red.
Keep your high-visibility apparel clean and well-maintained. Contaminated or dirty retroreflective materials provide lower visibility.
Replace garments that show signs of wear and tear, soiling, or contamination as it will no longer be able to provide acceptable levels of visibility.
Purchasers of HVSA should get proof that the materials used and the design of the garment meet the requirements of the CSA Z96-15 Standard.
What are the different classes of safety apparel?
The CSA Standard Z96-15 High-Visibility Safety Apparel sets out levels of retroreflective performance (i.e., the effectiveness of material in returning light to its source), the colours and luminosity of background materials, and how much of the body that should be covered by the high-visibility components. There are also special requirements for garments that to provide electrical flash and flame protection. Note that although specifications for apparel Classes are similar to those in ANSI/ISEA 107, these CSA Classes differ in that they specify body coverage rather than minimum areas.
CSA lists three classes of garments based on body coverage provided. Each class covers the torso (waist to neck) and/or limbs according to the minimum body coverage areas specified for each class.
Class 1 provides the lowest recognized coverage and good visibility.
Class 2 provides moderate body coverage and superior visibility.
Class 3 provides the greatest body coverage and visibility under poor light conditions and at great distance.
Details for each of the classes are listed below. For more details on the exact specifications, please refer to the Standard. (Note: While the Standard does not provide specifications for the application of high-visibility apparel to specific job types, the Guide does provide some examples of jobs where the different classes may be appropriate.)
Medium Risk: Class 2 or 3 based on certain conditions
Examples of situations that may be of medium risk:
When vehicles or equipment are moving between 40-80 km/h (25-50 mph).
Workers who require greater visibility under inclement weather conditions or low light.
When work backgrounds are complex.
When workers are performing tasks that divert attention from approaching vehicle traffic.
When work activities are in closer proximity to vehicles (in or near flowing vehicle traffic).
Examples of jobs include:
Roadway construction, utility, forestry or railway workers.
School crossing guards.
Parking and/or toll gate workers.
Airport baggage handlers and ground crews.
Emergency response personnel.
Members of law enforcement.
Accident site investigators.
And one that the guide did not include: Search and Rescue personnel.