Comment by lasersafetyguy

I think there are some misunderstandings in this thread about the IEC 60825 laser safety standards, and laser safety in general.

IEC 60825 is applicable to safety of laser products emitting laser radiation in the wavelength range 180 nm to 1 mm. So it does not just cover wavelengths that present a retinal hazard.

IEC 60825 is not a regulation, it is an international standard that governments may use to inform regulations. For example, in the US, laser products are regulated by the FDA through 21 CFR 1040.10 and 21 CFR 1040.11. These regulations are well aligned with the US national standard ANSI z136.1 and the international standard IEC 60825-1.

Emissions from lasers that present a retinal hazard are in general not additive. This is because beams coming from different directions focus onto different parts of the retina and any effect they have on the retina is localized. Thus the claim that 20 cars at an intersection all impinging on a viewer presents a 20-fold retina hazard is ill-founded. Emissions from beams that are primarily absorbed by the cornea, before they are focussed by the eye, do present an additive hazard to the cornea.

Regarding operation under faulted conditions, in particular a scanning failure, if the system's scan-failure shutoff latency is too long to prevent hazardous emission then it is a faulty product that has not been correctly classified. IEC 60825-1 explicitly requires evaluation of emissions under every reasonably foreseeable single point of failure. Generally speaking, a scanning failure is reasonably foreseeable.

While some lasers used for example in industrial processing are extremely powerful, the sort of lasers used in automotive lidars are quite modest in power. Low power lasers like traditional supermarket barcode scanners have been in common use since the 1970s and millions, probably billions, of people have been exposed to them without the dire consequences some posters seem to predict from automotive lidars.