Laser Safety in the USA (ANSI Z 136)
ANSI Z 136 requires specification according to OD (optical densities) only. ANSI allows a Nominal Hazard Zone (NHZ) to be determined by the laser safety officer.
Outside of the NHZ, diffuse viewing eyewear is allowed. Most Asian countries refer to these regulations. However Australia has recently adopted new laser safety regulations (AS1337.4/AS1337.5), which are based on the European laser safety regulations (EN 207/EN208).
Laser Safety in Australia and Europe AS1337.4/AS1337.5 (EN207/208/60825)
In Australia and Europe there is a second criteria to be taken into consideration, which is the power/energy density (i.e. the power/energy per area = per beam area). Diffuse viewing is not allowed, laser safety glasses have to protect against a direct hit.
Protection due to optical density alone is not sufficient when the material of the eyewear will not be able to withstand a direct hit. The regulations are called the norm, but in fact they are legal requirements and enforceable.
Other legal requirements (e.g. the regulations for industrial safety as well as the medical equipment regulations) refer to them as well.
AS 1337.4 (EN 207)
Laser eye protection products require direct hit testing and labelling of eye protectors with protection levels, such as D 10600 L5 (where L5 reflects a power density of 100 MegaWatt/m2 as the damage threshold of the filter and frame during a 10 seconds direct hit test at 10600nm).
Filter and frame have to fulfil the same requirements. It is not acceptable to select glasses according to optical density alone.
The safety glasses must be able to withstand a direct hit from the laser for which they have been selected, for at least 10 seconds (CW) or 100 pulses (pulsed mode).
Laser Resources offers LaserVision glasses, which are selected, tested and approved according to the Australian/European regulations and do not only guarantee the required minimum optical density, but also that the glasses will withstand the laser for which they have been selected for at least 10 seconds (CW) or 100 pulses (pulsed lasers).
The legal regulations require a single type test to achieve the CE-mark for a newly introduced product. LaserVision voluntarily makes its products subject to a much more complicated and costly procedure (DIN GS) in order to be able to guarantee a continuous quality that is always modern, even after many years.
The eyewear (filters as well as frames) is tested by an independent institute (e.g. in Germany the Physikalisch-Technische-Bundesanstalt PTB, DIN CERTCO, or Bayerisches Laserzentrum BLZ). The test house always applies the recent knowledge in laser technology and includes the manufacturer’s local quality management system into their testing.