How many first aiders does your workplace legally need? Most employers expect a fixed ratio — one first aider for every so many staff. There isn’t one. UK law sets no minimum number. What it sets is a duty, and alongside it sits official HSE guidance with suggested numbers in it. Get the duty wrong and, as the employer, that’s on you. Here is how the requirement actually works, and how to decide what “enough” looks like for your workplace.
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The law: “adequate and appropriate”
The legal duty comes from the Health and Safety (First-Aid) Regulations 1981. They apply to every employer in Great Britain — offices, shops, building sites, whether you employ one person or a thousand. The Regulations require you to provide “adequate and appropriate” first aid equipment, facilities and people, so that anyone injured or taken ill at work can be helped.
What counts as adequate and appropriate is deliberately not spelled out as a number, because a quiet office and a busy workshop don’t carry the same risk. You work out what’s adequate for your workplace by carrying out a first aid needs assessment. That part isn’t optional.
You need a first aid needs assessment
A needs assessment sounds bureaucratic. It’s mostly structured common sense. You look at four things and write down what you conclude:
- What you do. The nature of the work and the hazards involved. An accountancy practice and a joinery workshop are not the same risk profile.
- How many people, and when. Headcount, but also shift patterns and holidays. A first aider who leaves at 5pm is no cover for the night shift.
- Where you are. How quickly emergency services can reach you. A remote site needs more on-site capability, not less.
- Who’s on site. Young or lone workers, employees with known medical conditions, and members of the public visiting your premises.
Since 2024, HSE guidance also asks employers to consider mental health within the needs assessment when identifying training requirements. If HSE ever asks how you decided your first aid cover, your written assessment is the answer.
If you’d rather not build the assessment from scratch, our First Aid Needs Assessment tool walks you through these factors and produces a printable record you can keep on file.
How many first aiders? The HSE guidance numbers
These figures come from HSE guidance — they are suggestions, not statute — but they’re the benchmark an inspector will measure you against. They scale with both headcount and hazard level.
Low-hazard workplaces (offices, shops, libraries)
| Number of employees | Suggested provision |
|---|---|
| Fewer than 25 | At least one appointed person to take charge of first aid arrangements |
| 25 to 50 | At least one first aider trained in Emergency First Aid at Work (EFAW) — the one-day course |
| More than 50 | At least one first aider trained in First Aid at Work (FAW) — the three-day course — for every 100 employed (or part thereof) |
Higher-hazard workplaces (construction, manufacturing, warehousing)
| Number of employees | Suggested provision |
|---|---|
| Fewer than 5 | At least one appointed person |
| 5 to 50 | At least one first aider trained in EFAW or FAW, depending on the type of injuries that might occur |
| More than 50 | At least one FAW-trained first aider for every 50 employed (or part thereof) |
An appointed person takes charge of first aid arrangements — looking after the equipment and calling the emergency services. They don’t legally need training, though a short course is sensible. And remember: these numbers assume cover across every shift, so factor in holidays and absence rather than counting a single first aider who is only sometimes in the building.
Which course: EFAW or FAW?
The needs assessment points you to a training level. The two workplace standards are:
- Emergency First Aid at Work (EFAW) — a one-day course (6 hours of learning) suited to smaller or lower-risk workplaces.
- First Aid at Work (FAW) — a three-day course (18 hours) for larger or higher-hazard environments, covering a wider range of injuries and conditions.
You can compare dates, locations and prices from accredited providers across the UK on our first aid courses pages.
The three-year deadline most businesses miss
First aid certificates — both EFAW and FAW — are valid for three years from the date of issue. After that the qualification lapses, and there is no grace period: an expired certificate holder can no longer act as a first aider for the purposes of the Regulations. Requalification is a shorter course if you catch it in time, so renew before the certificate expires to avoid a gap in cover. HSE also recommends a short annual refresher (around half a day) in between, to keep skills current.
Most businesses that fall short on first aid don’t fail the assessment. They fail the calendar — a lapsed certificate nobody diaried. Keep your renewal dates somewhere you’ll actually see them. You can renew through the EFAW Refresher or the relevant FAW requalification course.
Frequently asked questions
How many first aiders does the law require?
The Health and Safety (First-Aid) Regulations 1981 set no fixed number. They require “adequate and appropriate” provision, which you determine through a first aid needs assessment. HSE guidance then suggests numbers based on your headcount and hazard level.
Is a first aid needs assessment a legal requirement?
Carrying out an assessment of your first aid needs is how you meet the duty to provide adequate and appropriate cover. Keeping a written record is strongly advised as evidence that you assessed your requirements.
What’s the difference between EFAW and FAW?
EFAW is a one-day course for lower-risk workplaces. FAW is a three-day course covering a wider range of injuries and conditions, intended for higher-risk environments. Your needs assessment indicates which level is appropriate.
Do first aid certificates expire?
Yes. Both certificates last three years, with no grace period after expiry. Requalify before the certificate lapses to keep continuous cover, and consider HSE’s recommended annual refresher in between.
Finding the right course
Envico is an independent training intermediary: we don’t deliver courses ourselves, we help UK businesses find and compare accredited providers. Start with the First Aid Needs Assessment tool to confirm how many first aiders you need and at what level, then compare dates and locations across all our providers on the first aid courses pages.