4.2 Safety Barriers
Wherever practicable, the barriers or shielding around fixed installation should be arranged so that the accessible dose rate does not exceed 2.5 μSv/hr. If this is not practicable, the maximum accessible dose rate must not exceed 7.5 μSv/hr. For radiography, a suitably marked barrier must be set up at a point where the dose rate is 7.5 μSv/hr. The barrier should consist of pennants suspended by rope or tape and should be marked with a notice incorporating the trefoil symbol and: