Working Environment Measurement Standards Ministry of Labour Notification No. 46 of April 22, 1976 Latest Amendments: Ministry of Health, Labour and Welfare Notification No. 191 of April 27, 2001 In Japanese (Definition) Article 1. In this notification, the definition of terms listed in the following items shall be as specified in each item concerned : (1) Liquid absorption sampling method: This method is such that an amount of sample air is passed through or contact with the surface of a liquid absorbent, and by that process substances to be measured are gathered into the liquid by solution, reaction or other mechanisms with the liquid. (2) Solid adsorption sampling method : This method is such that an amount of sample air is sucked through a layer of solid sorbents and substances to be measured are caught by those solid particles by adsorption etc. (3) Direct sampling method : This method is such that an amount of sample air is directly collected into a collecting vessels such as bag or bottle without using such methods as dissolution, reaction, adsorption, etc. (4) Cooling condensation sampling method : This method is such that an amount of sample air is condensed by being brought to contact with the surface of a cooled pipe, etc., and substances to be measured are gathered by condensation. (5) Filtration sampling method : This method is such that an amount of sample air is sucked through a fitter (limited to such a filter capable of collecting more than 95% of particles of 0.3 micron) and substances to be measured are gathered by filtration. (Measurement of Dust Concentration etc.) Article 2. The concentration of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon in the air of such indoor workplaces prescribed in item 1, Article 21, the Enforcement Order of Industrial Safety and Health Law (Cabinet Order No. 318, 1972, hereinafter referred to as the Cabinet Order) shall be measured in accordance with the provisions specified in the following :
(1) Vertical and horizontal lines are drawn at equal intervals of not more than 6m on the floor of a unit work area (refers to such a necessary section that is designated for working environment based on the condition of distribution of harmful substances and range of movement of workers within the area of a workshop concerned, hereinafter the same shall apply) and a sampling point is provided at each intersection of those lines at a position 50 to 150 cm above the floor (except such a point where measurement is very difficult due to equipment etc.). However, when it is obvious that the concentration of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon is substantially uniform, vertical and horizontal lines can be drawn at equal intervals of more than 6 m on the floor of a unit work area and a sampling point provided at each intersection of those lines. (1-2) Sampling points shall be provided at not less than 5 proper points though when they become less than 5 points then the above rule is applied regardless of the provisions of the preceding item. However, when the unit work area is very narrow and it is obvious that the concentration of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon is substantially uniform, the number of sampling points may be less than 5. (2) The measurement prescribed in the preceding items shall be made at such time when work is regularly performed. (2-2) At such a unit work area where work is performed at a place in close vicinity to the source of emission of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon in addition to the measurement prescribed in preceding three items, measurement shall be made at such a time when the concentration of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon in the air seems to become the highest of those hours during which the work is performed at such a position where the work is performed. (3) The collection of sample air at one sampling point shall be made continuously for not less than 10 minutes. This rule, however, does not apply to such a case wherein measurement is made by the relative concentration indication method. (4) The concentration of dust of sand and stones, rocks, ores (minerals), metallic materials or carbon in the air shall be measured by one of the following methods. a) Filtration sampling method using a particle size separator and gravimetric analysis. b) Relative concentration indication method (this is limited to such a case wherein the method listed in a. is simultaneously performed at more than one measuring point in the unit work area concerned). 2. A particle size separator prescribed in a) of item 4 shall be such a separator that has the characteristics shown in the following diagram, or for those separators which do not have the characteristics shown in the following diagram, such a separator that is capable of obtaining a value equal to a measured value which is obtained by a particle size separator proved to have said characteristics.
Remarks : In this diagram, P, D, and DO shall be defined as follows P : Penetration Rate D : Aerodynamic Particle Diameter of Dusts(µm) DO : 7.07 µm Aerodynamic Particle Diameter of Dusts 3. Notwithstanding the provision of item 4 of paragraph 1, the measurement of the concentration of dust may be done by the relative concentration indication method only under the approval of the Chief of the Labour Standards Inspection Office who exercises jurisdiction over the area where the work area concerned is located (hereinafter referred to as the "Chief of the competent Labour Standards Inspection Office"). The approval may be given in case of the evaluation of working environment measurement which is prescribed in paragraph 1, Article 26-2, Ordinance on Prevention of Hazards due to Dust (Ministry of Labour Ordinance No. 18, 1979) has been done more than 2 years, and those results are all classified into Control Class 1. In this case measurement shall be made in accordance with the following instructions: (1) The equipment to be used for the measurement shall be calibrated at least once every year periodically by one designated by the Director General of the Labour Standard Bureau, Ministry of Health Labour and Welfare. (2) The conversion factor into mass concentration (K-factor) shall use a value which is produced by the equipment calibrated by the provisions of the preceding item or a value which is decided by the Director General of the Labour Standard Bureau, Ministry of Health Labour and Welfare. 4. An employer who wishes to apply for the approval stipulated in the preceding paragraph shall fill in the Request for Special Approval on Working Environment Measurement (Form No. 1) and the Notification of Result of Working Environment Measurement (Form No. 2) attached to the following documents: (1) A sketch of the workplace (2) Drawing (s) showing the emission source of substances to be measured in the unit work area, the arrangement of major facilities and the sampling points
5. The Chief of the competent Labour Standards Inspection Office shall, upon deciding whether or not to approve the petition specified in paragraph 3, notify the decision to the said employer in writing as soon as possible. 6. An employer who has been approved in compliance with paragraph 3 shall, as soon as the evaluation of working environment measurement which is done after the above approval is not to be classified into Control Class 1, report it in writing to the Chief of the competent Labour Standards Office. 7. The Chief of the competent Labour Standards Office shall revoke the approval, as soon as the said official recognized that the unit work area to have been approved by the provision of the paragraph 3 is not classified into Control Class 1 or difficult to keep the condition of Control Class 1, when the said official has received the report stipulated by the preceding paragraph or inspected the workplace. (Measurement of Temperature, Humidity, etc. ) Article 3. The measurement of temperature, humidity and radiant heat at such workplaces listed in item 2, Article 21 of the Cabinet Order (limited to those indoor workplaces (hot, cool and humid) listed in each item, Article 587, the Ordinance on Industrial Safety and Health, Ministry of Labour Ordinance No. 32, 1972) shall be made in accordance with the provisions prescribed in the following: (1) Sampling points (except a sampling point for measuring radiant heat) shall be provided in at least one position which is 50 to 150 cm above the floor at the central portion of the unit work area. (2) A point for measuring radiant heat shall be selected at such a position closest to the source of heat according to each source. (3) Measurement shall be made according to the classification shown in the left column of the following table by using a measuring instrument as specified in the right column of the table or a measuring instrument having equivalent or higher capacity than that of the specified one: Classification Temperature and humidity Radiant heat Measuring instrument Assmann's aspiration psychometer with 0.5 C minimum scale Black globe thermometer with 0.5 C minimum scale (Measurement of Noise) Article 4. The measurement of equivalent noise level at such indoor workplaces prescribed in item 3, Article 21 of the Cabinet Order (limited to those indoor workplaces listed in each item,
Article 588 of the Ordinance on Industrial Safety and Health) shall be made in accordance with the provisions specified in the following: (1) Vertical and horizontal lines are drawn at equal intervals of not more than 6 m on the floor of a unit work area and a sampling point is provided at each intersection of those lines at a position 120 to 150 cm above the floor (except such a point where measurement is very difficult due to equipment etc.). However, when it is obvious that the noise level at unit work area is substantially uniform, vertical and horizontal lines can be drawn at equal intervals of more than 6 m on the floor of a unit work area and a sampling point provided at each intersection of those lines. (2) Sampling points shall be provided at not less than 5 proper points though when they become less than 5 points then the above rule is applied regardless of the provisions of the preceding item. However, when the unit work area is very narrow and it is obvious that the noise level is substantially uniform, the number of sampling points may be less than 5. (3) At such a unit work area where work is performed at a place in close vicinity to the source of noise level in addition to the measurement prescribed in preceding two items, measurement shall be made at such a time when the noise level seems to become the highest of those hours during which the work is performed at such a position where the work is performed. (4) Measurement shall be made in accordance with the following instructions: a) An instrument (hereinafter referred to as 'sound level meter') to be used for measurement shall be such an instrument that conforms to the standards provided by JIS C1502 (sound level meter) or one that has equivalent or higher capacity. b) Measurement shall be made by using the A-weighted network of a sound level meter. (5) The measurement of equivalent noise level at one sampling point shall be made continuously for not less than 10 minutes. (Measurement of a Workplace in a Pit) Article 5. The measurement of concentration of carbon dioxide and temperature prescribed in item 3, Article 21 of the Cabinet Order (limited to those indoor workplaces listed in each item, Article 588 of the Ordinance on Industrial Safety and Health) shall be made in accordance with the provisions specified in the following: (1) Sampling points shall be provided in at least one point at an intermediate position between the entrance of a pit (when a branch point is provided between the entrance of a pit and a working face, a branch point closest to the face concerned) and a working face and at the face respectively. (2) Measurement shall be made according to the classification shown in the left column of the following table, by using a measuring instrument listed in the right column of the table or an
equivalent or higher instrument: Classification Measuring instrument Concentration of carbon dioxide Carbon dioxide detector tube Temperature Thermometer of 0.5 C minimum scale (Measurement in a Room of a Building) Article 6. The measurement of the content of carbon monoxide and carbon dioxide in a room of a building (office which is provided with a centrally controlled air conditioning) prescribed in item 5, Article 21 of the Cabinet Order shall be made in accordance with the provisions specified in the following: (1) Sampling points (except such a point for measuring atmospheric temperature) of at least one shall be provided at 75 to 120 cm above the floor surface at the central portion of a room. (2) Measurement shall be made during normal business hours of the room. (3) Measurement shall be made according to the classification shown in the left column of the following table by using a measuring instrument listed in the right column of the table or an equivalent or higher instrument: Classification Content of carbon monoxide Content of carbon dioxide Measuring instrument Carbon monoxide detector tube Carbon dioxide gas detector tube Room temperature and atmospheric temperature Thermometer of 0.5 C minimum scale Relative humidity Psychrometer of 0.5 C; minimum scale (Measurement of Dose Equivalent Rate or Like) Article 7. The measurement of dose equivalent rate of external radiation and concentration of radioactive substances in the air at a workplace (for radiation work) prescribed in item 6, Article 21 of the Cabinet Order (limited to those workplaces listed in sections, Article 53 of Ordinance on Prevention of Ionizing Radiation Hazards, Ministry of Labour Ordinance No. 41, 1972) shall be made at unit work areas. Article 8. The measurement of dose equivalent rate of external radiation at a workplace (controlled area) listed in item 1, Article 53 of the Ordinance on Prevention of Ionizing Radiation Hazards shall be made according to the classification shown in the left column of the following table by using a measuring instrument shown in the right column of the table: Classification Measuring instrument
Neutron rays Gamma rays or X-rays Counter tube type neutron detector system, scintillation counter type neutron detector system, thermoluminescene dosimeter or film badge Ionization chamber type irradiation dose rate meter, Geiger-Mueller counter type dose rate meter, scintillation counter type dose rate meter, ionization chamber type irradiation dosimeter, thermoluminescence dosimeter, film badge or fluoroglass dosimeter Article 9. The measurement of concentration of radioactive substances in the air at a workplace listed in item 2 (working rooms for handling radioactive substances) or 3 (work to mine and collect nuclear raw materials in a pit), Article 53 of Ordinance on Prevention of Ionizing Radiation hazards shall be made by the following methods: (1) According to the condition of radioactive substances shown in the left column of the following table, one of the sampling methods listed in the right column of the table shall be used: Condition of radioactive substance Particulates Gases Specimen collection method Liquid absorption or filtration sampling method Liquid absorption, solid adsorption, direct or cooling condensation sampling method (2) One of following analytical methods shall be used: a) The analytical methods are as follows: (when it is obvious that there is no radioactive substance emitting α-rays, or the concentration of the radioactive substance is obvious by the measurement of ionizing radiation other than α-rays, the analysis by method 1) may be omitted, and when it is obvious that there is no radioactive substance emitting β-rays, or the concentration of the radioactive substance is made clear by the measurement of ionizing radiation other than β-rays, the analysis by method 2) may be omitted, and when it is obvious that there is no radioactive substance emitting γ-rays, or the concentration of the radioactive substance is made clearly by the measurement of ionizing radiation other than γ- rays, the analysis of method 3) may be omitted respectively.) 1) Total α-radioactivity measuring method or α-ray spectrometric analysis 2) Total β-radioactivity measuring method or β-ray spectrometric analysis 3) Total γ-radioactivity measuring method or γ-ray spectrometric analysis b) Radiochemical analysis c) Fluorophotometric analysis when the concentration of uranium in the air is measured. 2. Notwithstanding the provision set forth in the preceding paragraph, the measurement of concentration of gaseous radioactive substances in the air may be made by the direct
indication method. (Measurement of Concentration of Specified Chemical Substance etc. ) Article 10. The measurement of concentration of those substances listed in 1 to 7, item 1, Attached Table 3 of the Cabinet Order and in 1 to 36, item 2 of the same Table, in the air of such workplaces (indoor workplaces wherein to manufacture or handle the specified chemical substances, or a workplaces wherein to manufacture coke on a coke oven) listed in item 7, Article 21 of the Cabinet Order shall be made as provided in the following: (1) Measurement shall be made according to the classification listed in the left column of Attached Table 1 by using a sampling method listed in the middle column of the Table or an equivalent or higher method in capacity and an analytical method listed in the right column of the Table or an equivalent or higher method in capacity. (2) The measurement of concentration of asbestos (excluding amosite and crocidolite) dust in the air shall be made by one of the following methods: a. Filtration sampling method and numerical counting method b. Filtration sampling method and X-ray diffractometry 2. Notwithstanding the provisions of preceding item 1, the measurement of concentration of those substances in the air listed below may be made by a method using a gas detector tube. This rule, however, does not apply to such a case when the concentration of one of those substances listed in the following items is to be measured and a co-existing substance other than the substance concerned may adversely affect an accurate measurement. 1) Acrylonitrile 2) Vinyl chloride 3) Chlorine 4) Hydrogen cyanide 5) Hydrogen fluoride 6) Benzene 7) Hydrogen sulfide 3. Notwithstanding the provisions of the preceding two paragraphs, in case of the measurement of items 1 through 7 of the preceding paragraph, it may be done by a method using a gas detector tube only under the approval of the Chief of the competent Labour Standards Inspection Office. The approval may be given in cases where the evaluation of working environment measurement which is prescribed in paragraph 1, Article 36-2, Ordinance on Prevention of Hazards due to Specified Chemical Substances (Ministry of Labour Ordinance No. 39, 1972) has been done for more than 2 years, and those results are all classified into Control Class 1. In this case, measurement for chemicals listed in item 1 of paragraph 1 should be simultaneously performed at more than one measuring point in the unit work area concerned. 4. The provisions set forth in items 1 to 3, paragraph 1 of Article 2 shall apply mutatis mutandis to the measurement provided in the preceding three paragraphs. In this case, "dust
of sand and stones, rocks, ores (minerals), metallic materials or carbon" prescribed in items 1, 1-2 and 2-2, paragraph 1 of the same Article shall be read as "substances listed in 1 to 7, item 1, Attached Table 3 of the Cabinet Order and those listed in 1 to 36, item 2, the same Table", and "relative concentration indication method" described in proviso of item 3 of the same paragraph shall be read as "direct collection method or a method using a gas detector tube". 5. The provision of paragraphs 4 through 7, Article 2 shall apply to the approval provided in paragraph 3. (Measurement of Concentration of Lead) Article 11. The measurement of concentration of lead in the air at such an indoor workplace (lead work) prescribed in item 8, Article 21 of the Cabinet Order shall be made by using the filtration sampling method or a method having equivalent or higher capacity, and colorimetry or atomic absorption analysis or an analytical method having equivalent or higher capacity. 2. The provisions prescribed in items 1 through 2-2, paragraph 1, and the main text of item 3 of Article 2 shall be applied mutatis mutandis to the measurement provided in the preceding paragraph. In this case, "dust of sand and stones, rocks, ores (minerals), metallic materials or carbon" described in items 1, 1-2 and 2-2, paragraph 1 of the same Article shall be read as "lead." (Measurement of Concentration of Oxygen and Hydrogen Sulfide) Article 12. The measurement of concentration of oxygen and hydrogen sulfide in the air at a workplace (workplaces involving danger of oxygen deficiency) prescribed in item 9, Article 21 of the Cabinet Order shall be made as provided in the following: (1). Sampling points numbering at least 5 shall be provided at proper positions for detecting the condition of the distribution of concentration of oxygen and hydrogen sulfide in the air in the said workplace. (2). Measurement shall be made according to the classification shown in the left column of the following table by using a measuring instrument listed in the right column of the table or a measuring instrument having equivalent or higher capacity. Classification Concentration of oxygen Concentration of hydrogen sulfide Measuring instrument Oxygen analyzer or galvanometric oxygen meter of oxygen detector tube Hydrogen sulfide detector tube (Measurement of Concentration of Organic Solvent) Article 13. The measurement of concentration of those organic solvents listed in items 1 to 47 of the Attached Table 6-2 of the Cabinet Order in the air at an indoor workplace prescribed in
item 10, Article 21 of the Cabinet Order shall be made according to the classification of substances listed in the left column of Attached Table 2 by using the sampling method listed in the middle column of the Table, or a method having equivalent or higher capacity, and the analytical method listed in the right column of the Table or method having equivalent or higher capacity. 2. Notwithstanding the provisions in the preceding paragraph the measurement of concentration of those substances in the air listed below may by made by a detector tube. This rule, however, dose not apply to such a case wherein the concentration of one of those substances listed in the following items is measured and a co-existing substance other than the said substance may adversely affect an accurate measurement: 1) Acetone 2) Isoprovpyl alcohol 3) Isopentyl alcohol (otherwise known as isoamyl alcohol) 4) Ethyl ether 5) Xylene 6) Cresol 7) Chlorobenzene 8) Chloroform 9) Isobutyl acetate 10) Isopropyl acetate 11) Ethyl acetate 12) n-butyl acetate 13) Carbon tetrachloride 14) Cyclohexanone 15) 1,2-Dichloroethylene (otherwise known as acetylene chloride) 16) N, N-Dimethylformamide 17) Styrene 18) Tetrachloroethylene (otherwise known as perchlorethylene) 19) 1,1,1-Trichloroethane 20) Trichloroethylene 21) Tolune 22) Carbon disulfide 23) 2-Butanol 24) Methyl cyclohexanone 3. Notwithstanding the provision of the preceding two paragraphs, in case of the measurement of substances in items 1 to 47 of Attached Table 6-2 of the Cabinet Order (For substances described in items 2, 6 to 10, 17, 20 to 22, 24, 26, 27, 29, 32, 34, 39, 40, 42 to 45 and 47, this is limited to such a case wherein the items are manufactured or used as a mixture in which the main item is one of the items of the preceding paragraph), it may be done by a method using gas detector tube only under the approval of the Chief of the competent Labour Standards Inspection Office. The approval may be given in cases where the evaluation of working environment measurement which is prescribed in paragraph 1, Article 28-2, Ordinance on Prevention of Organic Solvent Poisoning (Ministry of Labour Ordinance No. 36, 1972) has been done for more than 2 years, and those results are all classified into
Control Class 1. In this case, measurement for organic solvents listed in Paragraph 1 should be simultaneously performed at more than one measuring point in the unit work area concerned. 4. The provisions set forth in item 1 to item 3, paragraph 1 of Article 2 shall apply mutatis mutandis to the measurement provided in the preceding three paragraphs. In this case, "dust of sand and stones, rocks, ores (minerals), metallic materials or carbon" described in item 1 item 1-2 and item 2-2, paragraph 1 of the same Article shall be read as "organic solvent listed in items 1 to 47 of the Attached Table 6-2 of the Cabinet Order" and "relative concentration indication method" described in the proviso of item 3, the same paragraph shall be read as "direct collection method, or a method using a detector tube". 5. The provision of paragraphs 4 to 7, Article 2 shall apply mutatis mutandis to the approval provided in paragraph 3.