COLOR-VISION REQUIREMENTS OF FIREFIGHTERS

To perform their job safely firefighters must be able to identify colo urs on industrial gas cylinders, portable fire extinguishers, road tra ffic signals and several pieces of firefighting equipment. Although go od colour vision is necessary we believe that the existing colour visi on standard, which bars entry to the fire service to applicants who fa il more than two plates of the Ishihara test, is unnecessarily stringe nt. We have identified and quantified the colour coded information enc ountered by firefighters. Colours were plotted on the CIE chromaticity diagram (1931) and isochromatic zones, which document the colour conf usions of colour deficient observers, superimposed. This novel techniq ue established possible colour confusions in different types of colour deficiency. Analysis of the results showed that red/green dichromats (protanopes and deuteranopes), severe deuteranomalous trichromats who fail the Farnsworth D15 test, and protanomalous trichromats are unsuit able for firefighting work. However, people with slight deuteranomalou s trichromatism who pass the D15 test, are not disadvantaged and can b e employed safely as firefighters. A new colour vision standard and a new testing procedure is recommended.