Como Calcular a Dose de Ruído - NR 15 (Passo a Passo)

Introduction

This tutorial provides a comprehensive guide on calculating noise dose according to NR 15, annex 1. Understanding this calculation is vital for ensuring workplace safety and compliance with regulations. By following the steps outlined below, you will learn how to accurately assess noise exposure in your work environment.

Step 1: Gather Necessary Information

Before you begin the calculations, collect all relevant data:

• Noise Levels: Measure the decibel (dB) levels of the noise sources present in the workplace.
• Exposure Time: Document the duration of exposure for each noise level.
• Permissible Exposure Limit (PEL): Be aware of the maximum allowable exposure limits defined by NR 15.

Step 2: Understand the Formula

The calculation of noise dose is based on the following formula:

• Dose (%) = (T / T0) x 100
  • T is the total time of exposure at a specific noise level.
  • T0 is the reference time, which is typically 8 hours for an 85 dB exposure level.

Step 3: Calculate the Noise Dose

Follow these steps to perform the calculation:

1. Identify Noise Levels: List all the noise levels measured in the workplace.
2. Record Exposure Durations: For each noise level, note the time spent exposed.
3. Calculate Individual Doses:
   • For each noise level, calculate the dose using the formula.
   • Example for 85 dB:
     • If exposure time is 4 hours:

     Dose = (4 hours / 8 hours) x 100 = 50%
     

4. Sum Up the Doses: Add all individual doses together to get the total noise dose.

Step 4: Interpret the Results

After calculating the total noise dose:

• Evaluate Compliance: Compare the total dose against the permissible exposure limits.
• Identify Risks: If the dose exceeds the limit, it indicates potential risk for hearing loss and other health issues.

Step 5: Implement Controls

If the calculations show that the noise exposure exceeds safe limits:

• Consider Engineering Controls: Implement physical modifications to reduce noise at the source.
• Use Personal Protective Equipment (PPE): Provide ear protection to workers.
• Monitor Regularly: Make noise assessments a routine part of workplace safety checks.

Conclusion

Calculating noise dose according to NR 15 is essential for maintaining workplace safety. By following the steps outlined above, you can effectively assess noise exposure and implement necessary controls. For ongoing safety, ensure regular monitoring and keep updated with any changes in regulations or workplace conditions.