105. An employer shall ensure that a working platform—

(a) is of sufficient dimensions to permit the safe passage of employees and the safe use of any plant or materials required to be used, and provides a safe working area having regard to the work being carried out there,

(b) possesses a suitable surface and, in particular, is so constructed that the surface of the working platform has no gap—

(i) through which an employee could fall,

(ii) through which any material or object could fall and injure an employee, or

(iii) giving rise to other risk of injury to any employee, unless measures have been taken to ensure that no employee could be so injured, and

(c) is so erected and used, and maintained in such condition, as to prevent, so far as is reasonably practicable—

(i) the risk of slipping or tripping, or

(ii) any employee being caught between the working platform and any adjacent structure.