I.-The employer shall use appropriate means to delimit the supervised, controlled or radon zones that he has identified and shall limit access to them.
The employer shall delimit an extremity zone when the monitored and controlled zones do not allow extremity exposure to be controlled and compliance with the occupational exposure limit values provided for in articles R. 4451-6 and R. 4451-8 to be guaranteed.
II.-The employer shall put in place:
1° Specific signs appropriate to the designation of the zone;
2° Appropriate signage when the demarcation of supervised and controlled areas does not guarantee compliance with the dose limit value for the crystalline lens laid down in articles R. 4451-6 and R. 4451-8.