How Many First Aiders Do I Need on a Construction Site?

How many first aiders do I need on a construction site?

Every construction site must have adequate first aid provision. The number of first aiders depends on the number of workers, the types of hazards present, and how the site is laid out. HSE guidance L74 provides the framework, but the employer must carry out a needs assessment for their specific circumstances.

The legal requirement

The Health and Safety (First-Aid) Regulations 1981 require every employer to provide adequate and appropriate first aid equipment, facilities, and personnel. "Adequate and appropriate" is not a fixed number — it depends on the outcome of a first aid needs assessment.

Construction is classified as higher-risk work by the HSE. The first aid needs assessment for a construction site should consider the nature of the work, the hazards present, the number of workers, the site layout, and the distance from the nearest hospital or ambulance response point.

HSE recommended ratios

HSE guidance L74 provides indicative ratios for higher-risk workplaces such as construction sites:

Workers on site	Minimum provision
Fewer than 5	Appointed person + first aid kit
5 to 50	At least 1 FAW first aider
More than 50	1 FAW first aider per 50 workers

These are minimums. The needs assessment may increase the requirement. A site with confined space work, hot works, working at height, or demolition should consider additional cover. Sites in remote locations with longer ambulance response times should also increase their provision.

Adjustments for high-risk activities

The base ratios assume standard construction activity. Several factors increase the requirement:

Work at height (scaffolding, roof work, steel erection), confined space entry, hot works (welding, cutting, burning), demolition, excavation work, work with hazardous substances, and work near live services all increase the risk of serious injury. Sites with significant amounts of these activities should consider a ratio closer to 1 first aider per 25 workers.

The distance from the nearest hospital matters. A city-centre site within five minutes of an A&E department can justify a lower ratio than a rural site where ambulance response might take 30 minutes or more.

The needs assessment

The principal contractor should carry out a first aid needs assessment before the construction phase begins and review it as the project progresses. A site that starts with groundworks and 10 workers needs different cover from the same site during the superstructure phase with 80 workers.

The assessment should be recorded and included in the construction phase plan. It should name the first aiders, confirm their certificate validity dates, identify the location of first aid kits and the first aid room (if applicable), and describe the arrangements for contacting the emergency services.

Certificate validity and refresher training

A First Aid at Work (FAW) certificate is valid for three years. The first aider must complete a two-day requalification course before the certificate expires. HSE strongly recommends annual refresher training (half a day) to maintain skills between requalification courses.

If a first aider's certificate expires and they do not requalify, they can no longer be counted as a first aider in the needs assessment. The site must have a plan for covering gaps caused by leave, sickness, or certificate expiry.

Frequently asked questions

What is the difference between an appointed person and a first aider?

An appointed person is someone nominated to take charge of first aid arrangements and call the emergency services if needed. They do not need to hold a first aid certificate. A first aider holds a valid First Aid at Work (FAW) certificate and is trained to provide treatment for injuries and illness. Construction sites with more than five workers should have at least one FAW-qualified first aider, not just an appointed person.

Is Emergency First Aid at Work (EFAW) sufficient for a construction site?

EFAW is a one-day course covering basic life-saving skills. HSE guidance (L74) recommends that construction sites with higher-risk activities have workers trained to FAW standard (three-day course) rather than EFAW alone. EFAW may be adequate for low-risk construction sites with fewer than five workers, but for most construction sites, FAW is the appropriate standard.

Do subcontractor workers count towards the total?

Yes. The first aid needs assessment should consider everyone on site, including employees of subcontractors, self-employed workers, and visitors. If a subcontractor has their own first aider on site, that can count towards the overall provision, but the principal contractor should confirm this arrangement in writing and include it in the construction phase plan.

How many first aid kits do I need?

At least one first aid kit for every first aider on site. On larger sites, additional kits should be placed at strategic locations so that no worker is more than a few minutes from a kit. If work is spread across multiple floors or buildings, each area should have its own kit. The contents of a construction site kit should include items for dealing with cuts, burns, and eye injuries, which are the most common construction injuries.

Do I need a first aid room on a construction site?

HSE guidance suggests that a first aid room should be considered on sites with more than 250 workers. In practice, a clean, warm, well-lit space with a couch, blankets, drinking water, and hand-washing facilities is sufficient. Many sites use a designated welfare cabin. The room should be clearly signed and accessible.

What happens during shift overlaps and night shifts?

First aid cover must be available whenever workers are on site. If the site operates shifts, the needs assessment should ensure that each shift has adequate first aid provision. A site that is well covered during the day but has no first aider on the night shift is not meeting its obligations. The cover ratio applies per shift, not per day.