My understanding is that needle stick injuries ONLY become reportable when a person is diagnosed with a disease attributed to an occupational exposure to a biological agent.

The 'Sharps' regulations do not affect RIDDOR requirements but they should still be recorded and investigated. There is a good guidance doc HSIS7 covering recording and investigation. Strange though that the Sharp regs do not apply to our school nurses, but we have adopted the principles within HSIS7.

The regs came into force in May 2013 and I think they used to be examinable after 6 months?

Just to clarify the RIDDOR part of this.

Someone being diagnosed with HIV/Hep whatever after injury from a contaminated needle would be a reportable disease.

Someone getting a needlestick from a sharp known to have been used by someone with one of those diseases would be a reportable dangerous occurrence.

Toe you are accurate but skirting the edge when you say " there was no legal requirement to investigate accidents under H&S law"...

There is a long standing obligation under the Social Security (Claims and Payments) Regs for an employer to investigate any injury recorded in the BI510 accident book - but I guess this is not strictly 'health and safety' law - because HSE don't enforce it. Sounds a little bit like the myth busters hair splitting to me since many (if not all) H&S people do need to be aware of the law and to implement it or make sure their employers implement it effectively.....