Cabinet of Ministers Regulations No. 731 Riga, 30 June 2009 (pr. No 45 20) labour protection requirements for protection of employees against artificial optical radiation risks in the working environment Issued in accordance with the Labour Protection Act article 25 paragraph 18 i. General questions 1. labour protection requirements for the protection of workers against the risks in the working environment creates or may create artificial optical radiation (there could, optical radiation) exposure on workers, particularly to their eyes and skin. 2. Optical radiation: any electromagnetic radiation with a wavelength in the range of 100 nm to 1 mm. Includes the following types of optical radiation: 2.1. heterogeneous radiation: any optical radiation other than laser radiation: 2.1.1. ultraviolet radiation: optical radiation of wavelength range between 100 nm and 400 nm Ultraviolet range divided into UVA (315-400 nm), UVB (280-315 nm) and UVC (100-280 nm); 2.1.2. the visible radiation: optical radiation of wavelength range between 380 nm and 780 nm; 2.1.3. the infrared radiation: optical radiation of wavelength range between 780 nm and 1 mm. Infrared range divided into IR (780-1400 nm), ISB (1400-3000 nm) and ISC (3000 nm-1 mm); 2.2. laser radiation: optical radiation from a laser device that can cause or amplify electromagnetic radiation in the optical radiation wavelength range primarily by the process of controlled stimulated emission. 3. the irradiance or power density is the source of optical radiation power per unit area upon a surface, expressed in watts per square metre (W/m2). 4. Optical radiation scattering is the time (integral), expressed in joules per square metre (J/m2). 5. Brightness is optical radiation energy flow in a 3-d angle unit to the unit area, expressed in watts per square metre to steradian (W/m 2 · sr). 6. the level of exposure to optical radiation is radiant radiant exposure and radiance to which a combination of employees. 7. the rules apply to all areas of employment where workers work environment are or may be exposed to optical radiation. 8. the employer must not put employees that for exposure to optical radiation, the exposure limit values not exceeding the homogeneous radiation (annex 1) and exposure limit values for laser radiation (annex 2). 9. The exposure limit values are for exposure to optical radiation, which pursuant to the exposed workers are protected against the harmful effects on health. 10. compliance with these rules is an employer responsible. 11. Labour protection requirements under the control of the Labour Inspectorate.
II. determination of exposure to optical radiation and of the assessment of risks 12. Employer all workplaces take a first optical radiation risk assessment, determining whether there are sources of optical radiation, which could result in injury to the health of employees. 13. If working place is the source of optical radiation or employed health check results show that workers ' health has caused or could cause exposure to optical radiation, the employer shall assess the risks of optical radiation in accordance with the laws and regulations of the internal monitoring of the procedure. 14. If the employer establishes that the optical radiation creates or may create a risk to the safety and health of employees, he in accordance with the results obtained, if necessary, make the optical radiation measurements or calculations, taking into account the exposure limit values (annex 1 and 2), as well as the information provided by the manufacturer of the equipment on the irradiance level (if the equipment produces optical radiation). 15. Optical radiation measurements with calibrated measuring equipment, which according to the manufacturer's instruction for use is suitable for the measurement of optical radiation, shall carry out: 15.1. Metrology and accreditation agency Department-Latvian National Accreditation Bureau, according to the standard LVS EN ISO/IEC 17025:2005 "the competence of testing and calibration laboratories-General requirements" accredited laboratory; 15.2. the other Member States of the European Union, accredited institutions entitled to carry out measurements of optical radiation; 15.3. the competent authority or competent authorities for the protection of the work; 15.4. the labour protection specialists who got a second level of higher education under the employment protection legislation on labour protection training; 15.5. the person with the appropriate qualifications to carry out the measurements. 16. the employer in assessing the risks of optical radiation, with particular attention paid to the following factors: 16.1 level of exposure wavelength range and duration of the exposure on the population; 16.2. exposure limit values (annex 1 and 2); 16.3. any effects concerning the health and safety of employees who are exposed to particular risks (including adolescents, pregnant women and women who have recently given birth); 16.4. any possible effects on workers ' health and safety resulting from workplace interactions between optical radiation and photosensitising chemical substances; 16.5. any indirect effects (including temporary blinding, explosion or fire); 16.6. the condition for the existence of replacement equipment designed for optical radiation levels reduced; 16.7. health checks of employees, as well as to scientific research based information on the effects of optical radiation on workers ' health; 10.4. multiple sources of optical radiation interaction; 16.9. laser devices or other sources of optical radiation, which indicates the manufacturer of the equipment and the associated degree of danger, taking into account in particular the 3 B or 4. class laser devices or similar classifications of other sources of optical radiation hazards (medium-high or high); 16.10. the other information provided by optical radiation sources and associated equipment manufacturers. 17. the employer shall document all optical radiation risk assessment and measurement of results and keep them for three years. After the expiry of the said information shall be deposited in the archives.
III. Optical radiation hazard elimination or reduction

18. Eliminating or reducing risks of optical radiation, the employer shall comply with the statutory protection of the work of the General principles of protection. 19. the employer under the labour protection requirements set out in law consult workers or their fiduciaries on matters related to optical radiation risks in the working environment, as well as the possible participation of the workers. 20. the employer according to the results of the risk assessment shall take the necessary measures (including organizational, time of exposure reduction, rest pause) optical radiation risk prevention or reduced to a minimum (the lowest practical level) based on technical progress and using the latest features of optical radiation sources of risk control. 21. If, when carrying out the risk assessment, finds that the exposure limit values (1) and (2) may be exceeded, the employer shall measure the protection plan includes the following specific places of work to organisational and technical measures: 21.1. use working methods that reduce the risks of optical radiation; 21.2. choose equipment that has a smaller level of exposure to optical radiation, taking account of the work to be done; 21.3. take technical measures the levels of exposure to optical radiation to reduce, if necessary, installing the equipment levels of exposure to optical radiation reduction, including locking devices, shields or similar device employed in health; 21.4. ensure job design and work equipment maintenance and maintenance according to the legislation on labour protection requirements in the workplace and the use of work equipment; 21.5. optimizing job design and layout; 21.6. to limit the duration of exposure to optical radiation and level; 21.7. to provide employees with suitable individual protection and assistance; 21.8. take measures, in accordance with the equipment manufacturer instructions. 22. This provision, paragraph 21, places of work, the employer places the safety signs in accordance with the legislation on labour protection requirements for safety in the use of the marks. The employer shall ensure for hazardous area delimitations and limit access to those zones, if exposure to optical radiation risk is reasonable and technically feasible limits. 23. If the employer's labour protection measures risks of optical radiation, the exposure limit values to reduce the optical radiation however is exceeded, the employer shall: 23.1. immediately take steps to prevent the exposure of workers to optical radiation following and reduce its effects, making sure that it does not exceed the exposure limit values; 23.2. analyzes and determines the reasons for which the optical radiation above the exposure limit values; 23.3. making changes to employment protection measures, to prevent the optical radiation, the exposure limit value being exceeded again. 24. The employer shall ensure that workers exposed to optical radiation risk in the workplace, and their representatives are trained and informed in a comprehensible form: 24.1. optical radiation and possible risks to the safety and health of employees; 24.2. the protection measures that eliminate or minimise the risks of optical radiation impact on the safety and health of workers; 24.3. the results of optical radiation in the assessment of risks and their significance; 15.2. optical radiation due to the resulting health symptoms, early detection of health problems and action if health problems have arisen; 15.2. the circumstances in which workers are entitled to health surveillance, as well as the compulsory health examination; 24.6. safe working methods, as well as the correct and safe use of work equipment, to prevent or reduce to a minimum the risks of optical radiation; 15.3. the correct and appropriate use of personal protective equipment.
IV. health examination employed 25. If workers exposed to risks from optical radiation exposure exceeding the exposure limit values (annex 1 and 2), the employer shall provide employees compulsory health tests according to the regulations on the order of, the mandatory health check for the earliest possible diagnosis of optical radiation caused health problems and ensure the quality of health workers. 26. the employer, upon request, provide the optical radiation risk assessment results in availability of the worker, the worker's family doctor and occupational doctor, who carried out the health inspection of statutory employees. 27. If the mandatory health check finds health workers that occupational doctor assesses how exposure to optical radiation consequences: 27.1. the doctor informed his employees health test results and make recommendations to health care also after termination of the effects of optical radiation, and also inform the employer of the health inspection results according to legislation on the agenda, the mandatory health check; 27.2. the employer shall organise different health checks of employees who have been subjected to similar exposure to optical radiation; 27.3. the employer shall review the risk assessment carried out in accordance with the provisions of chapter II, and measures for the elimination or reduction of risks. 28. the employer shall provide employees health test results documentation. After the National Labour Inspectorate's reasonable request, the employer shall issue the health inspection copies. 29. the employer shall take into account the results of the health surveillance, planning and establishing arrangements for the protection of the optical radiation risk prevention or reduced to acceptable levels.
V. closing question 30. provisions shall enter into force on 27 April 2010.
Informative reference to European Union Directive provisions included in the law arising from the European Parliament and of the Council of 5 April 2006, Directive 2006/25/EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (artificial optical radiation) (19th individual Directive within the meaning of article 16(1) of Directive 89/391/EEC means). The Prime Minister, the children, family and integration Affairs v. Welfare Minister Dombrovskis. Note: the editorial Augul rules shall enter into force on 27 April 2010.  
Ministry of welfare presented in annex 1 the Cabinet 30 June 2009 the Regulation No 731 heterogeneous exposure values to optical radiation detection 1. Biophysical based optical radiation values can be determined by the following formulae:    


Values of Eλ (λ, t) which, Eλ spectral irradiance or spectral power density: the radiant power of the certain period of time on the surface of unit area, expressed in watts per square metre area and wavelength (nanometres) times (W/m2 · nm); Eλ (λ, t) and Eλ values obtained from measurements or may be provided by the manufacturer of the equipment; Eeff effective irradiance (UV range): calculated irradiance within the UV spectral weighted wavelength range 180 to 400 nm, expressed in watts per square metre (W/m2); (H) optical radiation: the time distribution (integral), expressed in joules per square metre (J/m2); Heff effective radiant exposure: with S (λ) spectral weighted radiation exposure, expressed in joules per square metre (J/m2); Euva total irradiance (UVA): calculated irradiance within the UVA wavelength range 315 to 400 nm, expressed in watts per square metre (W/m2); Huva optical radiation exposure: the time and wavelength dispersion (integral) or sum of the irradiance within the UVA wavelength range 315 to 400 mm of, expressed in joules per square metre (J/m2); S (λ) spectral weighting taking into account that the effects of UV radiation on eye and skin depends on the wavelength, (table 1.2) (dimensionless); t, Δt time, duration of the exposure, expressed in seconds (s); λ wavelength in nanometres (nm); Δ λ bandwidth measurement interval calculation, expressed in nanometres (nm); Lλ (λ), Lλ spectral radiance of the source expressed in watts per square metre to the nanometer in steradian (W/m 2 · sr · nm); R (λ) spectral weighting taking into account that the visible and IR heat-induced ocular damage depends on the wavelength (table 1.3) (dimensionless); LR actual radiance (thermal injury): calculated by R (λ) spectral radiance weighted, expressed in watts per square metre steradian (W/m 2 · sr); B (λ) spectral weighting taking into account that the blue light radiation induced photochemical visual damage depends on the wavelength (table 1.3) (dimensionless); LB actual radiance (blue light): calculated by B (λ) spectral radiance weighted, expressed in watts per square metre steradian (W/m 2 · sr); EB effective irradiance (blue light): calculated by B (λ) spectral weighted irradiance, expressed in watts per square metre (W/m2); EIS total irradiance (thermal injury): calculated irradiance within the infrared wavelength range 780 to 3000 nm, expressed in watts per square metre (W/m2); Eād the total irradiance (visible, IR and ISB radiation): calculated irradiance within the visible and infrared wavelength range 380 to 3000 from nm, expressed in watts per square metre (W/m2); Hād of optical radiation exposure: the time and wavelength dispersion (integral) or sum of the irradiance within the visible and infrared wavelength range 380 to 3000 nm, expressed from the joules per square metre (J/m2); α angular subtense: the angle against the visible source of a space, make milliradians (mrad). Apparent source is the real or virtual object that forms the smallest possible retinal image.
2. The formulae above can be replaced by the following expressions and discrete values: Notes: 1. the formula to be used depend on the range of radiation sources, and the results are compared with the corresponding exposure limit values indicated in table 1.1. 2. One source of optical radiation can be more than one exposure value and corresponding exposure limit value. 3. the designation of a) to o) corresponds to the rows in table 1.1.
table 1.1 the exposure limit values for non-coherent optical radiation Note: 1. the range of 300 to 700 nm covers parts of UVB, all UVA and most of visible radiation; However, the risks associated with it are usually referred to as the "blue light" hazard. Blue light strictly speaking covers only the range of approximately 400 to 490 nm. 2. Very little source for permanent fixation of the angular subtense 11 mrad, can convert < LB to EB. This usually applies only for ophthalmic instruments or a stabilized eye during anaesthesia. The maximum "stare time" is calculated as follows: tmax = 100/EB with EB expressed in W/m2. In the light of the eye movements during normal Visual tasks this does not exceed 100 s. table 1.2 S (λ) (dimensionless), 180 nm to 400 nm, λ (λ) S λ in nm, nm, nm, λ (λ) S S (λ) (λ) λ S λ, nm, nm, S (λ) 0.0120 180 0.1737 0.9434 324 0.000520 372 276 228 0.000086 229 0.1819 277 0.0126 0.9272 325 181 0.000500 182 0.0132 0.1900 278 0.000083 373 230 0.9112 0.000479 0.000080 374 183 326 231 279 327 0.8954 0.0138 0.1995 0.000077 0.0144 0.2089 0.000459 375 184 232 328 0.000440 376 0.000074 185 0.8800 280 0.0151 233 0.8568 0.000425 0.000072 377 329 0.2188 281 0.0158 234 186 0.2292 187 330 0.000410 378 0.000069 282 0.8342 0.0166 0.2400 0.8122 0.000396 331 379 283 235 0.000066 236 0.2510 284 0.7908 332 0.0173 188 0.000383 189 0.000064 0.0181 0.2624 237 380 285 381 0.000062 0.0190 0.7700 333 0.000370 190 0.2744 0.7420 334 0.000355 238 286 382 0.000059 0.0199 0.7151 335 191 0.2869 287 239 0.000057 0.0208 0.3000 0.000340 383 240 288 336 192 0.6891 0.000327 0.000055 0.0218 0.3111 241 289 193 384 0.6641 0.000315 0.000053 194 242 337 385 0.0228 0.3227 0.6400 0.000303 0.000051 195 290 338 386 243 339 0.000291 0.6186 0.0239 0.3347 291 196 0.3471 292 387 0.000049 0.5980 340 0.000280 0.0250 244 388 245 0.3600 0.5780 0.000047 0.0262 197 0.000271 198 0.000046 389 293 341 0.0274 0.3730 0.5587 0.000263 342 294 246 0.000044 247 0.3865 295 390 199 0.0287 343 0.5400 0.000255 0.000042 0.0300 0.4005 248 296 391 200 0.4984 0.000248 0.000041 0.0334 201 392 344 249 393 0.000039 0.4150 0.4600 345 0.000240 297 0.0371 202 0.4300 298 0.3989 346 0.000231 250 0.000037 251 0.4465 203 0.0412 394 0.3459 0.000223 395 0.000036 347 299 204 0.4637 300 0.3000 0.000215 0.0459 252 348 0.000035 0.0510 253 0.4815 396 205 301 349 0.000207 0.2210 0.000033 0.0551 254 0.5000 397 206 302 0.1629 0.000200 0.000032 207 0.0595 398 350 0.5200 0.1200 351 303 255 0.000191 0.000031 0.0643 0.5437 256 208 399 304 0.0849 352 0.000030 0.0694 0.5685 0.000183 400 209 257 353 0.000175 0.0750 258 210 0.0600 305 0.5945 0.0454 354 0.000167 211 0.0786 306 0.6216 307 0.0344 259 0.000160 0.0824 212 260 355 308 0.0260 0.6500 0.000153 0.0864 0.6792 356 213 0.0197 214 261 309 262 0.7098 310 357 0.000147 0.0906 0.000141 0.0950 0.7417 0.0150 358 215 263 0.000136 264 0.0111 359 216 311 0.0995 0.0081 360 0.000130 217 0.1043 0.7751 312 265 0.0060 0.000126 0.1093 0.8100 313 266 361 0.8449 362 218 0.000122 267 0.1145 314 0.0042 0.8812 315 219 0.0030 220 0.1200 268 363 0.000118 0.9192 316 0.000114 0.1257 221 0.9587 364 0.0024 269 0.000110 270 0.1316 365 222 317 0.0020 1.0000 318 223 0.1378 0.000106 271 0.9919 366 0.0016 319 0.000103 224 367 0.1444 272 0.0012 0.9838 320 0.000099 0.1500 273 0.9758 368 0.0010 225 321 0.000819 0.000096 0.1583 274 0.9679 369 226 0.000670 0.000093 227 0.1658 275 322 370 0.000540 0.000090 0.9600 323 371 1.3. table B (λ), R (λ) (dimensionless), 380 nm to 1 400 nm

λ, nm B (λ), R (λ) (λ) B λ, nm, R (λ) ≤ λ 300 380 380 385 0.01 0.01 0.1 < — 0.013 0.13 0.1 0.05 0.5 1 405 395 400 390 0.025 0.25 0.2 0.4 0.8 0.9 4 415 2 410 8 420 430 435 1 10 440 1 10 445 450 9 425 0.95 9.5 0.98 9.8 0.97 9.7 0.94 9.4 0.8 0.7 0.9 9 460 455 7 470 475 480 8 465 0.62 6.2 0.55 5.5 0.45 4.5 485 0,32 3,2 490 0,22 2,2 495 0,16 1,6 500 0,1 1 500 < λ ≤ 600 100,02· (450-λ) 1 600 < λ ≤ 700 0,001 1 700 < λ ≤ 1050 — 100,002· (700- λ) 1050 < λ ≤ 1150 — 0,2 1150 < λ ≤ 1200 — 0,2·100,02· (1150-λ) ≤ λ 1400-1200 < Welfare Minister u. 0.02 Augul Ministry of welfare has submitted version of the annex 2 Cabinet 30 June 2009 the Regulation No 731 laser optical radiation exposure values based on the Biophysical exposure values to optical radiation can be determined by the following formulae: where dP power expressed in Watts (W); da surface expressed in square metres (m2); E (t), E radiation intensity: the radiant power density on the surface of unit area, expressed in watts per square metre (W/m2). E (t) and E values derived from measurements or may be provided by the manufacturer of the equipment; (H) optical radiation: radiation energy distribution on the surface of unit area at a specific moment in time (time integral), expressed in joules per square metre (J/m2); T time, duration of the exposure, expressed in seconds (s); λ wavelength, expressed in nanometres (nm); cone angle γ measurements, expressed in milliradians (mrad); γm measurement angle of vision, expressed in milliradians (mrad); α angular subtense of a source expressed in milliradians (mrad); restrictive aperture: the circular area on which irradiance and radiant exposure; G integrated radiance: Radiance variability given exposure time expressed as radiant energy per unit area of the emitting of radiation surround multiples with unit of angle, expressed in joules per square metre steradian (sr J/m2 ·). Notes: 1. use the formula depends on the source of the radiation wavelength and duration, and the results are compared with the corresponding exposure limit values given in table 2.2 to 2.4. 2. One source of laser optical radiation can have several effects or impact values, such as sources may change the wavelength and can have different exposure times. Each case must apply to the appropriate exposure limit value. 3. Parameters and adjustment of values that are used in the calculations in table 2.2 to 2.4, are given in table 2.5, and their application, repeated exposure are listed in table 2.6.
table 2.1 laser radiation risks wavelength λ, nm wavelength range to which the organ exposed to the risks of exposure to UV 400 eye 180 of photochemical damage and thermal damage 2.2, 2.3 180 to 400 UV skin Erythema 2.4 400 to 700 visible eye retinal damage to the 600 400 2.2 eye photochemical damage 2.3 400 to 700 visible skin thermal damage up to 1400 700 ISA 2.4 eye thermal damage 2.2 700 to 1400, 2.3 IS skin thermal damage 1400 to 2600 2.4 ISB eye thermal damage 2.2 2600 to 106 ISC eye thermal damage 2.2 1400 to ISB, ISC 106 eye thermal damage to the ISB, ISC 106 1400 2.3 skin thermal damage 2.4 2.2. table laser radiation exposure to the eyes. Short exposure time < garums1 10 s wavelength (nm) opening duration (s) 10-13-10-11 10-11-10-9, 10-9-10-7 10-7-10-5 1.8 1.8 · · · 10-5-5 10-5 5-5-10-10 · 3 10-3-101-1 280 mm at 180 UVC t 10000 s. G and L γm must be used as a measurement of the average angle of vision. The official border between visible and infrared is 780 nm and determined by the international lighting commission (hereinafter referred to as the CIE) column with wavelength band names is intended only to give the user a better overview of the signs G used. The european committee for standardization (CEN); the notation Lt is used by CIE; the notation LP uses the IEC and the european committee for electrotechnical standardization (CENELEC hereinafter.) 3. Wavelength 1400 — 105 nm: aperture diameter = 3.5 mm wavelength 105 — 106 nm: aperture diameter = 11 mm 4. exposure value measurement considerations for γ is defined as follows: If α α (angular source pretnosacījum) > γ   γ (limiting cone angle, indicated in brackets in the appropriate box) then the measurement of the angle of sight is a fixed value of γ γm. If you use the greater angle of vision of the measurement, then the risk is assessed to be high. If the measurement of γ α angle < γm must be large enough to fully incorporate the sources, but otherwise there are no restrictions, and it can be greater than γ. table 2.4 the exposure limit values for laser exposure to the skin.
Wavelength (nm) opening duration (s) 10-9, 10-9,