A festival in a London park, a five-a-side tournament on a school field, a street food market with a few thousand visitors: each is a different scale of event, but every one of them creates the same legal question for whoever is running it. What level of first aid cover is actually required? Unlike workplace first aid, where the rules are fixed and familiar, event first aid cover in London is governed by a risk-based framework built around a single reference document: the Purple Guide.
This matters for the same reason community-responder schemes and public-access defibrillators matter — the chain of survival depends on qualified help reaching someone within minutes, and a temporary event with thousands of attendees and no ambulance access is a very different environment to plan for than a fixed building.
Why Event First Aid Isn’t the Same Question as Workplace First Aid
Employers have a fixed statutory duty to provide first aid to staff under the Health and Safety (First-Aid) Regulations 1981. Event organisers face a broader and less prescriptive duty. The Health and Safety at Work etc. Act 1974 and the Management of Health and Safety at Work Regulations 1999 require anyone running an event to carry out a risk assessment covering everyone who could be affected — attendees, contractors, and volunteers alike, not just paid staff. Guidance from the Health and Safety Executive treats an event site as a workplace from the moment setup begins to the moment breakdown finishes, which is why organisers are expected to think about first aid provision well before doors open to the public.
There is currently no single named law that sets a fixed first aid ratio for public events, which is different from what many organisers expect. Instead, the legal duty is to assess the risk properly and respond to what that assessment finds. That is expected to tighten: Martyn’s Law, developed following the Manchester Arena Inquiry, is set to introduce a formal requirement for premises and events of a certain size to plan for medical and emergency response, with oversight sitting with the Care Quality Commission.
The Purple Guide and the Medical Needs Assessment
The industry-standard reference for event first aid in the UK is The Event Safety Guide, universally known as the Purple Guide. It is published by the Events Industry Forum with input from the HSE, and it is the document that local authorities, licensing teams, emergency services, and Safety Advisory Groups all work from when they assess an event’s medical plan.
The Purple Guide deliberately moved away from the old approach of fixed “score sheet” ratios — a set number of first aiders per thousand attendees regardless of context. In its place is the Medical Needs Assessment, carried out by a competent person, which weighs several factors together rather than crowd size alone:
- The audience profile: age range, likely alcohol or substance use, and any history of casualties at similar events
- Site layout: distance to the nearest A&E and how easily an ambulance can actually reach the casualty
- Environmental conditions: heat, cold, and weather exposure across the event’s duration
- The nature of the event itself: a multi-day festival, a sporting fixture, or an event involving pyrotechnics or water carries different risk than a static market stall day
- On-site activities: temporary structures, raised platforms, and anything that increases the chance of injury
This means two events with identical attendance figures can require very different levels of medical cover, which is precisely the point — a seated, daytime community fair is not the same risk profile as a late-evening outdoor concert.
How Cover Typically Scales With Crowd Size
The Purple Guide is not prescriptive, but it does describe indicative tiers that give organisers and SAGs a starting point for discussion before the full Medical Needs Assessment is finalised.
| Approximate attendance | Risk level | Typical provision |
|---|---|---|
| Under 500 | Low | First aid kit and at least one or two people competent in first aid, able to call 999 |
| 500–2,000 | Medium | A nominated medical lead, trained first aiders, and a dedicated first aid point |
| 2,000–5,000 | Moderate | A clinical lead such as an HCPC-registered paramedic or nurse, a mixed clinical team, and an ambulance available for transfers |
| 5,000–10,000+ | High / complex | A full medical team including doctors, paramedics and nurses, a dedicated on-site treatment or triage area, and multiple ambulances |
General starting-point recommendations cited by event medical providers suggest roughly one trained first aider per 250 attendees once an event moves into higher-risk category, alongside a senior first aider or paramedic on site. None of these numbers substitute for the Medical Needs Assessment itself — they are a baseline an organiser can be asked to justify departing from, not a target to hit and stop.
Safety Advisory Groups and London Licensing Conditions
In London, most events above a few hundred attendees, or any event involving road closures, temporary structures, or an unusual venue, will be expected to engage with a Safety Advisory Group. SAGs are multi-agency panels, usually chaired by the local authority, that typically include representatives from the Metropolitan Police, London Fire Brigade, the London Ambulance Service, Transport for London, and relevant council departments such as licensing and highways.
SAGs are non-statutory — they cannot themselves grant or refuse permission for an event — but the individual bodies sitting on them each hold real enforcement powers, and a licensing authority will lean heavily on a SAG’s advice. Organisers are expected to submit an Event Management Plan and a risk assessment well in advance, with the medical plan as a core component. Separately, any event involving alcohol sales, regulated entertainment, or late-night refreshment needs a premises licence or a Temporary Event Notice under the Licensing Act 2003, and these licences commonly carry conditions that tie directly back to the first aid provision described in the medical plan.
What This Means for the Chain of Survival
Event first aid cover and community-responder schemes are solving the same underlying problem from different directions. A trained community first responder or a well-sited public-access defibrillator narrows the gap between collapse and professional help in everyday settings; a properly scaled event medical plan does the same job for the temporary, high-density crowds that a fixed local infrastructure was never designed to handle in the first place. Both depend on the same principle: provision has to be sized to the actual risk in front of it, assessed honestly, rather than assumed from a generic checklist. For anyone organising a public event in London, that means treating the Medical Needs Assessment as the real starting point — not the attendance figure on the ticket, and not a rule of thumb copied from the last event on the calendar.