2-11. Noise and Dust Measurement Procedures and How to Interpret the Reports

At factories and construction sites, noise and dust management is required by the Industrial Safety and Health Act and environmental laws and regulations. Long-term noise exposure, in particular, can cause health problems such as hearing loss, while dust increases the risk of pneumoconiosis and respiratory diseases. Therefore, regular measurements and accurate interpretation of reports are important for both ensuring employee health and ensuring compliance. Below, we explain the procedures for conducting noise and dust measurements and how to interpret reports.

1. Noise measurement procedure

As a rule, noise measurements are carried out by occupational environment measurement specialists who are nationally certified. The procedure is as follows:

- Identify the areas to be measured and identify machines and processes with high noise levels.

- Measurement points should be distributed evenly throughout the workplace, and measurements should be taken at 5 to 10 representative points.

- Place the measuring device (sound level meter) at the height of the worker's ears.

- Measure the A-weighting and time rate (equivalent sound pressure level) while the unit is in operation.

The results are expressed in decibels (dB), and if the standard value of 85dB is exceeded, hearing protection equipment and work time restrictions are required.

2. Dust measurement procedures

Dust measurements are also carried out by work environment measurement specialists. The main steps are as follows:

- Identify the source of dust (cutting, grinding, powder injection, etc.).

- Measurement points are placed in the workspace and samples are taken for a set period of time using a suction pump.

- Measure dust concentration using a gravimetric or light scattering measuring device.

・ Calculate the measurement results as a time-weighted average concentration (mg/m³).

In particular, it is strongly recommended that dust containing asbestos or specific chemical substances not exceed the standard values.

3. How to read the report

A report will be issued after the measurement. When interpreting it, check the following points:

- Measurement conditions: Are the date, work content, and operating status recorded correctly?

- Measurement results: Are the values for each measurement point clearly shown?

- Evaluation category: Whether the working environment falls into "First management category (good)," "Second management category (requires improvement)," or "Third management category (requires correction)."

・ Recommendations: Are improvement measures (strengthening ventilation systems, introducing local exhaust ventilation, instructions to wear protective equipment, etc.) clearly stated?

4. Improvement and follow-up

If the results of the report exceed the standards, immediate improvement measures must be considered and implemented. Typical measures include strengthening ventilation equipment, installing soundproof walls, reviewing work procedures, and making personal protective equipment mandatory. After that, re-measurements must be conducted to confirm the effectiveness of the improvements.

Noise and dust measurements are not just for compliance with laws and regulations, but also for protecting employee health and improving the working environment. By correctly understanding the measurement procedures and utilizing the reports, you can create a safe and sustainable working environment.