Radiation Protection (Non-Ionising Radiation) Regulations

Requirements for high power lasers

37.—(1) Every high power laser shall have a protective housing that prevents human access during operation to laser and collateral radiation that exceed the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule, respectively, wherever and whenever such human access is not necessary for the apparatus to perform its intended function. Wherever and whenever human access to laser radiation levels that exceed the AEL for Class 1 is necessary, these levels shall not exceed the limits of the lowest class necessary to perform the intended function of the apparatus.

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(2) Every high power laser shall be provided with a safety interlock for each portion of the protective housing which is designed to be removed or displaced during operation or maintenance, if the removal or displacement of such portion of the protective housing permit human access to laser or collateral radiation in excess of the AEL applicable under paragraph (1). Each required safety interlock, unless defeated, shall —

(a)	prevent such human access to laser and collateral radiation upon removal or displacement of such portion of the protective housing; and
(b)	preclude removal or displacement of such portion of the protective housing upon failure to prevent human access to laser and collateral radiation as required under paragraph (a). [S 517/2019 wef 01/08/2019]

(3) Every high power laser which incorporates safety interlocks designed to allow safety interlock defeat shall incorporate a means of visual or aural indication of interlock defeat. During interlock defeat, such indication shall be visible or audible whenever the laser product is energised, with the protective housing removed or displaced.

(4) Replacement of a removed or displaced portion of the protective housing shall not be possible while required safety interlocks are defeated.

(5) Every high power laser shall incorporate a readily available remote control connector having an electrical potential difference of no greater than 250 r.m.s. volts between the terminals of the remote control connector. When the terminals of the connector are not electrically joined, human exposure to all laser and collateral radiation from the laser emitting apparatus in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule shall not be allowed.

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(6) Every high power laser shall incorporate a key-actuated master control. The key shall be removable and the laser shall not be operable when the key is removed.

(7) Every high power laser shall incorporate an emission indicator which provides a visible or audible signal during emission of accessible laser radiation in excess of the AEL for Class 1, and such emission indicator, shall, prior to emission of such radiation, allow appropriate action to be taken to avoid exposure to the laser radiation.

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(8) If the laser and laser energy source are housed separately and can be operated at a separation distance of greater than 2 m, both laser and laser energy source shall incorporate an emission indicator as required in accordance with paragraph (7).

(9) Any visible signal required by paragraph (7) shall be clearly visible through protective eyewear designed specifically for the wavelength of the emitted laser radiation.

(10) Any emission indicator referred to in paragraph (7) shall be located so that viewing does not require human exposure to laser or collateral radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule.

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(11) Every high power laser shall be provided with one or more permanently attached means, other than laser energy source switches, electrical supply main connectors, or key-actuated master control, capable of preventing access by any part of the human body to all laser and collateral radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule.

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(12) Every high power laser shall have operational and adjustment controls located so that human exposure to laser or collateral radiation in excess of the AEL for Class 1 is unnecessary for the operation or adjustment of such controls.

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(13) All viewing optics, viewports and display screens incorporated into a high power laser shall at all times limit the levels of laser and collateral radiation accessible to the human eye by means of such viewing optics, viewports or display screens to less than the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule.

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(14) For any shutter or variable attenuator incorporated into such viewing optics, viewports or display screens, a means shall be provided —

(a)	to prevent access by the human eye to laser and collateral radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule whenever the shutter is opened or the attenuator varied; and [S 517/2019 wef 01/08/2019]
(b)	to preclude, upon failure of such means as required in sub-paragraph (a), opening the shutter or varying the attenuator when access by the human eye is possible to laser or collateral radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule. [S 517/2019 wef 01/08/2019]

(15) Every high power laser which emits accessible scanned laser radiation shall not, as a result of scan failure or other failure causing a change in either scan velocity or amplitude, permit human access to laser radiation in excess of the AEL permitted for that class of laser.

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(16) Every high power laser shall be provided with a manual reset to enable resumption of laser radiation emission terminated by the use of a remote interlock or after an interruption of emission in excess of 5 seconds duration due to the unexpected loss of main electrical power.

(17) Every high power laser shall be under the direct and personal supervision of a licensed laser operator.

(18) Every high power laser shall be provided with a key operated “ON-OFF” switch.

(19) Any licensee using a high power laser apparatus shall be able to perform any of its functions without the need for exposure to laser and collateral radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule when the radiation is not intended to be viewed by them. Any area where levels of laser radiation in excess of the AEL for Class 1 and the AEL for collateral radiation specified in Table 5 in the Second Schedule exist shall be clearly identified by posting a sign or by the use of barriers or guards or both to prevent unauthorised entry into these areas.

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(20) Whenever laser output must be limited to less than the maximum power available, the laser output power shall be measured, adjusted and recorded before it is used.

(21) Every safety device, such as interlock, shall be functionally tested and recorded before it is used.

(22) Every high power laser shall be secured against any unauthorised operation.

(23) The following precautions shall be taken during any alignment procedure:

(a)	the alignment shall be performed with the laser radiation emission reduced to the lowest practicable level;
(b)	only persons required to perform alignment shall be in or near the beam path; and
(c)	protective eyewear shall be worn where necessary to prevent hazardous exposure.

(24) Every high power laser when fully assembled and operating with its service controls and user controls adjusted to yield the maximum emission, shall function in such a manner that the intensity of laser radiation at all accessible locations, when measured within a stationary circular area of 0.385 cm² and averaged over that area does not exceed the following limits:

(a)	during any time interval of less than 1.8 × 10^-5 seconds, an integrated irradiance of 5.0 × 10^-7 J/cm²;
(b)	during any time interval, t seconds, that is greater than 1.8 x 10^-5 seconds but less than or equal to 10 seconds, an integrated irradiance of 1.8 × 10^-3 × t^0.75 J/cm ²;
(c)	during any time interval of greater than 10 seconds but less than or equal to 10,000 seconds, an integrated irradiance of 0.01 J/cm²; and
(d)	during any time interval of greater than 10,000 seconds, an irradiance of 1 µW/cm ².

(25) Every high power medical laser shall comply with all the relevant requirements set out in paragraphs (1) to (23). In addition, the manufacturer of the laser shall —

(a)	incorporate in each high power medical laser a means for the measurement of the level of that laser radiation intended for irradiation of the human body with an error in measurement of no more than ± 20% when calibrated in accordance with sub-paragraph (b). Indication of the measurement shall be in International System Units;
(b)	supply with each high power medical laser instructions specifying a procedure and schedule for calibration of the measurement system required by sub-paragraph (a);
(c)	affix to each high power medical laser, in close proximity to each aperture through which is emitted accessible laser radiation in excess of the AEL of the accessible bearing, the words: “Laser Aperture”; and [S 517/2019 wef 01/08/2019]
(d)	provide a target-indicating device.

(26) A high power laser or high power medical laser is to be treated as complying with all the relevant requirements in this regulation if —

(a)	it is classified in accordance with any standard specified in the Seventh Schedule; and
(b)	it complies with the requirements for high power lasers or high power medical lasers (as the case may be) in that standard that correspond to the relevant requirements in this regulation. [S 517/2019 wef 01/08/2019]

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