General - What are Upper and Lower Action Values?
Action values are the legal measurements of noise where action as an employer is required.
For example the Noise at Work Regulations 2005 in the UK is a document that highlights the maximum Noise exposure and Peak sound levels that an operative can be exposed to before needing to wear hearing protection.
The noise exposure can be calculated over each day, or if the noise exposure varies significantly over the week, can be calculated over the week.
Below is a summary of the lower, upper and limit action values and what reaching that level means for the workers on site.
Action Value Groupings
Noise at Work Regulation for Noise Exposure |
Noise Exposure (LEP,d / LEX,8hr) |
Noise Exposure (Dose) |
Peak Sound Level |
| dB(A) | % | dB(C) | |
| Lower Action Value (Without hearing protection) | 80 dB(A) | 31.6 % | 135 dB(C |
| Upper Action Value (Without hearing protection) | 85 dB(A) | 100 % | 137 dB(C) |
| Upper Exposure Limit Value (With hearing protection) | 87 dB(A) | 157 % | 140 dB(C) |
What these categories mean
Meaning for employer |
|
| Lower Action Value (Without hearing protection) | Perform a risk assessment pertaining to risks associated with the health and safety of staff as a result of noise in the workplace. Provide suitable Hearing protectors to employees who wish to use them, but not enforce the use. Provide employees with information, instruction and training on current noise levels as well as the risks associated with it. |
| Upper Action Value (Without hearing protection) | Personal noise exposure levels should be reduced as far as is reasonably practicable, without the use of hearing protection. e.g. quieter tools, noise barriers installed around noise sources or staff rotation between noisy and quiet operations. Where it is impractical to reduce noise levels sufficiently, staff should be provided with adequate hearing protection. Based on the results of quantitative measurements, noise maps should be drawn up which clearly indicate Hearing Protection Zones (HPZs) and the areas demarcated accordingly. Any individual, staff or visitors, permanently in the HPZ or just passing through, should be instructed to wear the appropriate hearing protection. Employees working in the HPZs are required to undertake health surveillance in the form of Audiometric testing. |
| Upper Exposure Limit Value (With hearing protection) | When the Exposure Limit Value is reached, the employer is required to reduce noise levels at the ear of employees to below 87dB(A), by making the site quieter or rotating shifts as before. This does however take the effect of the hearing protection into account. Therefore, an external noise level of 95dB(A) may for example be acceptable, as long as the employer can prove that the provided HPDs provide adequate protection to below at least 87 dB(A). |