You must consult someone who has a full understanding of ISO/IEC60825-1 2014 and has had training in its implementation as a "Laser Safety Officer". If you work at a university, school or government department, such places employ or have access to the time of a Laser Safety Officer. Only such people are qualified to advise on laser safety.
So my questiom could be clarified/re-phrased as: "what are my options for measuring the 'safeness' of a light-source, in relation to the tolerances of the average human eye?"
Read and understand the specification of IEC60825 "Class 1" in detail; there are no shortcuts and no short answers. The light source must fall within Class 1 if it gets into peoples' eyes, which it clearly does as this is a "display" application, or, if a scanning or wide beam display, Class 1M. If Class 1M, then you must take steps to make sure that only naked laser light reaches peoples' eyes and no viewing instruments are used. Thus a public display rules out Class 1M and only Class 1 is going to be acceptable. IEC60825 gives you details on the measurements you must make. You're going to make a calculation of the level of power and duty cycle (if it's a pulsed source) that reaches peoples' eyes in each wavelength range specified and check that these are within the allowed thresholds of IEC60825.