I've been asked to look into writing a poilcy with procedures in the event that a member of staff cuts themselves / clean -up.

I work for a group of farms which grow and prepare food for distribution. The system is similar to that of a conveyor belt system with staff cutting food products into batches etc.

Can anyone offer or point me in the right direction of a good example of a Blood policy

I am not too sure if it is still available but I have an old copy of a publication (2003) by the Advisory Committee on Dangerous Pathogens (ACDP) called "Infection at Work: Controlling the risks" it includes just the sort of scenario you describe including model risk assessments and could be just the thing to point you in the right direction. You could try the HSE website to see if it is still around.