The tables hereto annexed and designated: "Table 1-Maximum Permissible Corneal Exposure for Direct Illumination or Specular Reflection of Laser Radiation"; "Table 2-Maximum Permissible Skin Exposure"; "Table 3-Maximum Permissible Output Densities for Non-Enclosed Laser in an Uncontrolled Area (Limits for Low-Intensity Lasers)"; and "Table 4-Attenuation of Laser Safety Eyewear" are hereby made part of this Part (rule).
TABLE 1
MAXIMUM PERMISSIBLE CORNEAL EXPOSURE FOR DIRECT ILLUMINATION OR SPECULAR REFLECTION OF LASER RADIATION*
Q-switched 1 nanosecond to 1 microsecond pulse [10-9 - 10-6 sec.] (joules/cm2) | Non-Q-switched 1 microsecond to 0.1 of a second pulse [10-6 - 10-1 sec.] (joules/cm2) | Continuous wave or pulse width greater than 0.1 of a second duration [Greater than 10-1 sec.] (watts/cm2) |
1.0 × 10-7 ** | 1.0 × 10-6 ** | 1.0 × 10-5 ** |
1.0 × 10-3 *** | 1.0 × 10-2 *** | 1.0 × 10-2 *** |
* The values in this table assume a diffraction limited and zero order transverse mode beam. In the case of a higher order transverse mode in a gas laser where the intrinsic beam divergence exceeds one milliradian the values may be increased on the basis of experimental evidence. Because of the lack of data, no explicit value is listed for the maximum permissible corneal exposure for laser radiation in the wave length range below 400 nm. or for sub-nanosecond pulses; therefore the cornea shall not be directly exposed to this radiation until MPCE values have been established for these conditions.
** For lasers operating in the wave length range 400-1400 nm.
*** For lasers operating in the wave length range above 1400nn.
TABLE 2
MAXIMUM PERMISSIBLE SKIN EXPOSURE*
Energy Density Pulsed [Q-switched, Non-Q-switched] | Power Density, Continuous Wave |
(joules) | (watts) |
(cm2) | (cm2) |
0.1 | 1.0 |
* For lasers operating in the visible, near-infrared and infrared regions of the electromagnetic spectrum. No information is available on permissible skin exposures to laser radiation in the wave length range below 400 nm. Therefore, caution must be used to avoid such exposure until experimental data is available on permissible levels.
TABLE 3
MAXIMUM PERMISSIBLE OUTPUT POWER OR ENERGY DENSITIES FOR A NON-ENCLOSED LASER IN AN UNCONTROLLED AREA (LIMITS FOR LOW-INTENSITY LASERS)
Q-switched 1 nanosecond to 1 microsecond pulse [10- 9 - 10-6 sec.] (joules/cm2) | Non-Q-switched 1 microsecond to 0.1 of a second pulse [10-6 - 10-1 sec.] (joules/cm2) | Continuous wave or pulse width greater than 0.1 of a second duration [Greater than 10- 1 sec.] (watts/cm2) |
1.0 × 10-1 | 1.0 | 3.0 |
TABLE 4
ATTENUATION OF LASER SAFETY EYEWEAR*
Suggested Maximum Incident Density | |||||
O.D. | Attenuation (db)** | Attenuation Factor | Q-switched Max. Energy Density (J/cm2) | Non-Q-switched Max. Energy Density (J/cm2) | Continuous Wave Maximum Power Density (W/cm2) |
1 | 10 | 10 | 10-6 | 10-5 | 10-4 |
2 | 20 | 102 | 10-5 | 10-4 | 10-3 |
3 | 30 | 103 | 10-4 | 10-3 | 10-2 |
4 | 40 | 104 | 10-3 | 10-2 | 10-1 |
5 | 50 | 105 | 10-2 | 10-1 | 1 |
6 | 60 | 106 | 10-1 | 1 | 10 |
7 | 70 | 107 | 1 | 10 | |
8 | 80 | 108 | 10 | 102 |
* Because of limitations of safety eyewear material, no eyewear shall be exposed to more than 400 joules or 10 watts of incident laser energy or power, respectively.
** (db) = Decibel. A unit to express a beam intensity ratio. The decibel is equal to 10 times the logarithm of the beam intensity ratio expressed by the following equation:
n(db) = 10 log10(P1)/(P2)
where P1 and P 2 designate the input and output power density or energy density, respectively, and "n" designates the number of decibels corresponding to their ratio.
Footnotes
* The values in this table assume a diffraction limited and zero order transverse mode beam. In the case of a higher order transverse mode in a gas laser where the intrinsic beam divergence exceeds one milliradian the values may be increased on the basis of experimental evidence. Because of the lack of data, no explicit value is listed for the maximum permissible corneal exposure for laser radiation in the wave length range below 400 nm. or for sub-nanosecond pulses; therefore the cornea shall not be directly exposed to this radiation until MPCE values have been established for these conditions.
** For lasers operating in the wave length range 400-1400 nm.
*** For lasers operating in the wave length range above 1400nn.
N.Y. Comp. Codes R. & Regs. Tit. 12 § 50.23