Legionella Risk Assessment Review Frequency: When to Revisit It

A legionella risk assessment should be reviewed when there is reason to believe it may no longer reflect the building or the way it is managed.

Triggers include plumbing changes, new tanks or heaters, occupancy changes, vulnerable users, poor monitoring results, failed samples, incidents, or significant remedial works.

A review might confirm the assessment remains suitable, require targeted updates, or show that a full reassessment is needed.

Keep a record of the review decision, including who reviewed it, what evidence was checked, and what changed afterwards.

Do not wait for an arbitrary anniversary if site conditions have materially changed before then.