Challenging a permit in English

You may need to stop work held by someone senior to you, possibly from the contractor organisation. The language must be immediate, polite and impossible to misread.

Stop first, explain second. "Stop work, please. I need to check the isolation before you continue."

Name the concern, not the person. "The isolation list shows one valve. The line has two sources of pressure." Not: "You did not isolate it properly."

Ask for the document. "Can you show me the isolation certificate, please?"

State what has to happen. "Work can restart when the second valve is locked and tagged and the certificate is updated."

Practise these four moves until they are automatic. Under pressure you will use the sentences you have rehearsed, not the ones you have only read.