I would like opinions please on the following scenario.

Do you think it a reasonable request for a supermarket to supply safety footwear to its employees who wheel out large wheeled metal cages containing produce for the shelves? There have already been instances of toes/feet being driven over.

Not unreasonable at all, this is best practice in many similar situations i.e. warehouses, car parks, and loading bays etc. Do you know what the risk assessment states about wearing safety footwear though?

Depends.
Is rolling a cage over the toes likely to result in injury?
How many of the instances that have happened resulted in injury?

It may be that it's reasonably foreseeable for a trolley to go over toes, but ordinary shoes are sufficient to protect from injury. In that case, the RA will presumably not mandate safety shoes, but will prohibit flipflops etc.

Depends on whether the students are 6th form or University (i.e. under 18 = young person or over)? Regardless of age duty extends to all employees.

Given that supermarkets give low hours and low wages to keep employees from any NI Contributions it is highly likely that considerations such as PPE would also be low on their agenda. The distribution hubs that load these cages generally employee temporary staff via agencies who are required to provide their own PPE in the form of boots and Hi-Vis.

Indeed looking around this evening deciding what was for dinner a number of store staff moving cages had those well know safety footwear brands of Nike, Adidas and Puma.

The problem we have here is some organisations such as supermarkets fail to assess the risks correctly and introduce the appropriate control measures. If a worker suffers an injury as a result of moving these cages it will cost more than a pair of safety shoes long term. There can be a considerable weight in one of those cages and I'm sure it could lead to a nasty injury, We have cages at work to move the product from one area to another and safety boots with ankle support must be worn.

As for agency staff having to supply their own p.p.e. this is only the case if a person is genuinely self employed. e.g. arranges their own tax and national insurance contributions and not bogus self employed we here about nowerdays.