The Industrial Safety and Health Act, in conjunction with the Labor Standards Act, is a law aimed at ensuring the safety and health of workers in the workplace and promoting the creation of a comfortable working environment by promoting comprehensive and systematic measures for preventing industrial accidents, such as establishing hazard prevention standards, clarifying responsibility systems, and promoting voluntary activities.
Chapter 7 of the Industrial Safety and Health Act mandates that employers conduct "work environment measurements" and record the results in indoor workplaces and other workplaces where hazardous work is performed, as a measure to maintain and promote health (Article 65, Paragraph 1 of the Industrial Safety and Health Act). Furthermore, Article 65, Paragraph 2 stipulates that "work environment measurements" must be conducted in accordance with the "work environment measurement standards" established by the Minister of Health, Labour and Welfare.
The workplaces where "work environment measurements" should be conducted are specified in Article 21 of the Enforcement Order of the Industrial Safety and Health Act, and of these, eight indoor workplaces that generate significant noise are specified in Article 588 of the Industrial Safety and Health Regulations. In addition, the "Guidelines for Preventing Noise-Related Hearing Discomfort" (Notification No. 546) lists 52 workplaces (Appendix 2 of the Guidelines) that are likely to have an equivalent noise level of 85 dB(A) or higher, in addition to the eight locations mentioned above (Appendix 1 of the Guidelines).
*Notifications issued by the Director of the Labor Standards Bureau of the Ministry of Labor are called "Kihatsu".
The measurement method is stipulated in Article 4 of the "Workplace Environment Measurement Standards" as follows:
- Measurement points shall be located at a position between 120 cm and 150 cm above the floor at the intersection of vertical and horizontal lines drawn at equal intervals of 6 m or less on the floor surface of the unit work area (excluding locations where measurement is extremely difficult due to equipment, etc.). However, if it is clear that the noise level in the unit work area is nearly uniform, the intersection point for the measurement point may be the intersection of vertical and horizontal lines drawn at equal intervals exceeding 6 m on the floor surface of the unit work area.
- Notwithstanding the provisions of the preceding paragraph, even if the number of measurement points falls below five according to the provisions of that paragraph, the number of measurement points shall be five or more for each unit work area. However, this shall not apply if the unit work area is extremely small and it is clear that the noise level in that unit work area is nearly uniform.
- In a unit work area where work is performed in close proximity to a sound source, in addition to the measurements specified in the preceding two paragraphs, measurements shall be taken at the location where the work is performed during the time when the noise level is expected to be highest.
- Measurements shall be carried out as follows:
(i) The equipment used for measurement (hereinafter referred to as "sound level meter") must be capable of measuring equivalent sound levels.
(b) The frequency weighting circuit of the sound level meter should be used with the A-weighting characteristic. - The measurement time for the equivalent sound level at a single measurement point must be a continuous period of 10 minutes or more.
In the "Guidelines," the measurement method that calculates the average value of 5 or more mesh intersections according to paragraphs 1 and 2 above is called "A measurement," and the measurement in a location close to the sound source according to paragraph 3 is called "B measurement."
The method for evaluating the measurement results is stipulated in the "Guidelines for Preventing Noise-Related Hearing Discomfort" (Notification No. 546). The average value of measurement A (arithmetic mean of measurement values of 80 dB(A) or higher from measurement A) and the results of measurement B are evaluated by applying them to the following table.
| A: Average value of measurement \ B: Measurement | Less than 85 dB(A) | 85 dB(A) or higher and less than 90 dB(A) | 90 dB(A) or more |
| Less than 85 dB(A) | Management category I | II Management Classification | Management category III |
| 85 dB(A) or higher and less than 90 dB(A) | II Management Classification | II Management Classification | Management category III |
| 90 dB(A) or more | Management category III | Management category III | Management category III |
Based on the evaluation results of the work environment measurement, the business operator must take the following measures for each management category:
| Management category I | To strive to maintain the working environment. |
| II Management Classification | Measures should be taken to clearly indicate the location with signs or other means. Inspect facilities, equipment, work processes, or work methods, and based on the results, take necessary measures to improve the work environment, such as installing or maintaining facilities or equipment, improving work processes or work methods, and endeavor to ensure that the management classification of the location falls under Management Class I. Workers engaged in noisy work should be required to use soundproofing equipment as needed. |
| Management category III | Measures should be taken to clearly indicate the location with signs or other means. Inspect facilities, equipment, work processes, or work methods, and based on the results, take necessary measures to improve the work environment, such as installing or maintaining facilities or equipment, improving work processes or work methods, so that the management classification of the location falls under Management Class I or Management Class II. Furthermore, when measures are taken to improve the work environment, conduct work environment measurements at the location to confirm their effectiveness and evaluate the results. Workers engaged in noisy work must be required to use hearing protection equipment, and notices regarding the use of hearing protection equipment must be posted in a place easily visible to workers while they are working. |
Furthermore, when measurements of the work environment are taken, the measurement results are evaluated, and countermeasures are implemented, the following information must be recorded and retained for three years each time. The guidelines also state that if the measurement results fall under Management Category II or Management Category III, it is desirable to retain the records for five years.
- Measurement date and time
- Measurement method
- Measurement point
- Measurement conditions
- Measurement results
- Evaluation date
- Evaluation points
- Evaluation results
- Name of the person who performed the measurement and evaluation
- When corrective measures are taken based on the results of measurement and evaluation, an outline of those measures should be provided.
Furthermore, employers must conduct health checkups for workers who are regularly engaged in noise-generating work.
In future installments, we plan to introduce other laws and regulations related to weighing and measurement.
(Excerpt from the email newsletter issued on October 20, 2011)
