Similar to Glenn and Scampi I'm skeptical of how you'd be sure that the hairnets aren't becoming a FB hazard whilst being hung and handled i.e hair going onto the outside of the net or falling onto another PPE item during handling. Generally hairnets are removed after other PPE to control this.
7.4.4 Protective clothing shall be changed at an appropriate frequency, based on risk.
Interpretation Changing protective clothing
Protective clothing needs to be changed at an appropriate frequency to ensure that clothing cannot
become a source of product contamination. The frequency of changes must be based on risk (e.g. using
visual inspections, swabbing or contact plates). For example, hairnets are changed daily or whenever they
are removed.
If you can validate that there is no risk of re-using the hairnets than perhaps feasible - olenazh has illustrated this to be possible in any case (I'm curious as to the details).
One thing to consider also is customer compliance. Even if you do find a way to pass this with BRC, if you have any specific customer COPs I'd check those, as it may not necessarily fly with customer auditors despite it being ok with BRC.
Alternatively, ban eating and toilet breaks so that by default your staff don't have to leave and re-enter