Lack of information, instruction and training is often the root cause of a lot of these incidents.
Protection offered by PPE is rarely complete. Think of it as the last line of defence to control a risk after all other control measures have been implemented, or where a foreseeable failure of such measures could expose workers to danger.
It’s made clear in the Personal Protective Equipment at Work Regulations that employers are responsible for providing suitable PPE and associated training and employees are duty-bound to use PPE when required.