http://www.legislation.gov.uk/uksi/2017/1075/made/data.pdf

Brings in revised Radon work place exposure levels

​​​​​​​As per regulations 1999:

(b) any work (other than a practice) carried out in an atmosphere containing radon 222 gas at a concentration in air, averaged over any 24 hour period, exceeding 400 Bq m−3 except where the concentration of the short-lived daughters of radon 222 in air averaged over any 8 hour working period does not exceed 6.24 × 10−7Jm−3

As per regulations 2017:

(b) any work (other than a practice) carried on in an atmosphere containing radon 222 gas at an annual average activity concentration in air exceeding 300 Bq m−3

Edited by user 30 November 2017 15:13:37(UTC)  | Reason: Not specified

Currently, any work carried out in an atmosphere containing radon at a concentration greater than 400 Bq m-3 over a 24-hour period, is in scope of the Ionising Radiation Regulations (IRR). This value has now changed to an annual average concentration greater than 300 Bq m-3.

Calculations carried out by Public Health England have shown that a 24-hour average of 400 Bq m-3 is equivalent to an annual average of 300 Bq m-3. Therefore, there is no change to the existing value, so there will not be any additional impacts on business.

Existing arrangements state that if radon is detected in the workplace above this level then the employer must notify HSE immediately. The proposal outlined by the Directive would mean that notification was only required once the duty holder had detected that radon was present above the specified level and tried and failed to remediate below this level.

HSE feels that during the remediation period (which is not time-limited) workers and the public can be exposed to an uncontrolled high level of radon and HSE would not be aware of this exposure as they are not required to notify. Therefore, HSE think this provision is confusing and lessens radiological protection significantly and therefore propose that current arrangements are maintained regardless of remediation.