First-aid personnel should be available at all times people are at work, based on assessments of risk and number of workers.
Where there are special circumstances, such as remoteness from emergency medical services, shiftwork, or sites with several separate buildings, there may need to be more first-aid personnel than set out below. Increased provision will be necessary to cover for absences.
| Category of risk | Numbers employed at any location | Suggested number of first-aid personnel |
| Lower risk eg shops and offices, libraries | Fewer than 50
| At least one appointed person At least one first aider One additional first aider for every 100 employed |
| Medium risk eg light engineering and assembly work, food processing, warehousing | Fewer than 20
| At least one appointed person At least one first aider for every 50 employed (or part thereof) One additional first aider for every 100 employed |
| Higher risk eg most construction, slaughter houses, chemical manufacture, extensive work with dangerous machinery or sharp instruments | Fewer than five
| At least one appointed person At least one first aider One additional first aider for every 50 employed |
