Are over-specs EN 166 compliant?

They can be — an over-spec is tested and marked in its own right, and must carry the impact grade and fields of use the task requires. Compliance fails not on the marking but on suitability: the regulation 4(3) test of fit, ergonomics and effectiveness for the actual wearer and duration.

Can employees be required to wear over-specs instead of prescription safety glasses?

Only while over-specs remain suitable for the task and wearer. Where all-shift wear, fogging, optical quality or fit make them unsuitable in practice, the employer’s duty is to provide the suitable alternative — prescription safety eyewear — free of charge.

Do over-specs go over any glasses?

They are sized for typical spectacle frames, but fit depends entirely on what the wearer’s own frames happen to be — large or wrap-style everyday frames often break the seal or create pressure points. The combination has to be assessed as worn, not assumed.

What should be issued for dust or splash environments when the wearer has a prescription?

A sealed goggle with a prescription insert — the goggle body provides the certified fields (3, 4, 5 or 9 as marked on the frame) and the insert carries the correction. Over-specs are unsealed and cannot claim those fields unless their own frame marking shows them.

Are Over-Specs Compliant? Over-Glasses Safety Eyewear, Honestly — Certus

Over-specs are legitimate EN 166 PPE — until the suitability test says otherwise. When they pass, when they fail, and what to issue instead.

Certus is a UK platform for managing prescription safety eyewear compliance to EN 166, covering hazard assessments, ordering, optician verification and certificate records. Operated by Certus Safety Ltd, registered in England and Wales, company number 17364362.