A guide for anyone who organises events indoors and wants to keep attendees safe(r) from the life-altering impacts of Covid-19 and other airborne diseases.
Thank-you for thinking about ways to make people safer at your event.
There are seven Covid safety measures in this guide. Many are cheap or free, although some require upfront investment and some take more time.
The measures are in order of relative effectiveness, but all can be effective. No single measure is perfect, so a combination is ideal (the ‘Swiss Cheese’ Model).
But it’s better to use any safety measures than none at all.
We offer two options for implementing each safety measure:
- robust (heart 💚): recommended safest action.
- minimum (circle 🟠): less safe, but better than nothing.
Measures should apply to everyone: staff, volunteers, organisers, and attendees.
If you don’t have much time, check out: 🤯 Where to start if you’re overwhelmed.
These days Covid is mostly talked about in the past tense. Covid-19 safety measures are no longer common, so you need to explain why you are putting them back in place to avoid confusion.
You may be asking people to change their ‘normal’ behaviour. Others may assume that your safety information is a mistake, left over from the early days of the pandemic.
Being upfront and clear about what you are doing and why (i.e. to keep everyone safer, especially people who are at higher risk) is a vital part of making your Covid safety measures effective.
Ask people at your event how your Covid measures impacted them. Seek feedback in particular from the disabled and Covid-conscious communities.
An event sickness policy encourages people with symptoms of illness (e.g. coughing, sneezing, vomiting, fever) to stay away. This helps to remove the risk (infectious people) altogether.
💚 Robust: People are asked not to come if they are unwell. Refunds are available on request. Visibly unwell attendees are asked to leave.
🟠 Minimum: People are asked not to come if they are unwell.
💔 Absent: No messaging about illness.
👣 Step-by-step guide: Sickness policy: how can I put this measure in place?
🧪 The Science: Sickness policy: why is this measure helpful?
Offering options for people to join your event remotely means that if someone is unwell, they are more likely to attend online rather than showing up in person. This helps remove the risk (infectious people) altogether. An additional benefit is improving inclusion for people who cannot attend in-person events.
💚 Robust: Attendees can join the event remotely (eg online) in a meaningful and active way.
🟠 Minimum: Remote (online) participants can observe, but not actively participate.
💔 Absent: No remote (online) joining options.
👣 Step-by-step guide: Remote access: how can I put this measure in place?
🧪 The Science: Remote access: why is this measure helpful?
Testing requirements encourage people who are testing positive with Covid-19 to stay away. This helps to remove the risk (infectious people) altogether. Rapid Antigen Tests (also known as Lateral Flow Tests or LFTs) for Covid-19 are not perfect but rarely return false positives; if someone tests positive, they almost certainly have Covid-19.
💚 Robust: People coming to the event are required to test for Covid on the day. Test status is asked about on entry and tests are available if people forget or can’t afford them.
🟠 Minimum: People coming to the event are requested to take a Covid test before arrival.
💔 Absent: No test requests or requirements.
👣 Step-by-step guide: Testing: how can I put this measure in place?
🧪 The Science: Testing: why is this measure helpful?
Ventilation means providing fresh air and removing polluted, stale air. It helps to dilute and remove aerosols that carry viruses like Covid-19 and flu through the air, which float and move like smoke. Someone who has Covid-19 will be breathing it into your event space. Without ventilation, the volume of infectious aerosols in the shared air at your event will increase throughout.
💚 Robust: Multiple windows and/or doors fully opened to the outside throughout the event space, and/or the venue has a fresh air ventilation system that is on throughout.
🟠 Minimum: One window/door to the outside is opened at regular intervals.
💔 Absent: The event has no fresh air ventilation.
👣 Step-by-step guide: Ventilation: how can I put this measure in place?
🧪 The Science: Ventilation: why is this measure helpful?
Air purification uses air filters to remove particles such as allergens, exhaust fumes and viruses from the air. While purification doesn’t stop all infections, particularly those passed on at close-range, studies show it reduces risk of infection from airborne diseases such as Covid-19. HEPA-grade purifiers filter 99% of infectious particles.
💚 Robust: Air purifier(s) are on during the event and are sufficient for the event size.
🟠 Minimum: At least one air purifier is on during the event.
💔 Absent: No air purification.
👣 Step-by-step guide: Air purification: how can I put this measure in place?
🧪 The Science: Air purification: why is this measure helpful?
CO2 monitors tell you how ventilated your event space is. Humans breathe out carbon dioxide (CO2), so the level of CO2 in a space tells you how much of the air has been breathed out by other people and is a useful proxy measure for the risk of infection with airborne illnesses. As a general rule, a higher level of CO2 means a higher risk. When you let in fresh air to your event space, CO2 levels and infection risk will reduce.
💚 Robust: There is a CO2 monitor in a central location and event organisers take action to improve ventilation if CO2 levels go too high.
🟠 Minimum: There is a CO2 monitor in place for information only.
💔 Absent: No CO2 monitoring.
👣 Step-by-step guide: CO2 monitoring: how can I put this measure in place?
🧪 The Science: CO2 monitoring: why is this measure helpful?
Masks are highly effective at filtering out viruses if they are well-fitting and good quality. When in close contact with someone with an airborne illness (e.g. sitting next to them inside for an hour), a mask is the most reliable tool we have to prevent infections. Masks can prevent you from both catching or spreading illness.
Masks have sadly become stigmatised and politicised, which can make people who wear them feel isolated or/and physically unsafe at events. Including masking in your event’s accessibility measures counters this feeling and promotes inclusion.
💚 Robust: Masks are required and provided.
🟠 Minimum: Masks are encouraged or welcomed, but not mandatory.
💔 Absent: No masking information or provision.
👣 Step-by-step guide: Wearing masks: how can I put this measure in place?
🧪 The Science: Wearing masks: why is this measure helpful?
This is not one of the more effective ways to reduce Covid risk. Hand washing with soap and water is an essential part of general infection prevention and control. However, on its own, it is not effective at preventing airborne illnesses like Covid-19 because the virus is primarily spread through the air when people breathe out.
🧪 The Science about Covid and hand-washing
Vaccination against Covid-19 is a very important public health measure that we support. You can get vaccines at Boots and other pharmacies if you are not eligible for NHS vaccines.
We don’t include vaccination on our list of suggested safety measures because vaccination status is no longer easily provable when admitting people to events and you can spread Covid-19 even if vaccinated.
If you are short on time or/and cash, focus on the Covid safety measures below.
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5. Air purification 🌬️ (Sheffield folks can borrow purifiers for free!)
These are the easiest first steps. Just like with all safer spaces and accessibility measures, it will take trial and error before you find what works best for you.
Take additional measures when you can, ask us for advice, and don’t give up!
How can I put this measure in place??
Tell people that you don’t want them to show up if they are sick or unwell. Clearly communicate your event’s sickness policy in the event description, at booking, and in event reminders. Let people know that this policy is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable.
Be clear that attendees who turn up unwell will not be allowed entry.
List common illness symptoms that you want people to take into account: these should include flu- and cold-like symptoms such as a cough, sore throat, runny nose, and sneezing, and gastrointestinal symptoms like vomiting and diarrhoea.
Ideally, provide the option of attendees requesting refunds if they are unwell and can’t attend - you can assess these on a case by case basis.
Invite attendees who have a chronic condition (e.g COPD, hayfever) that may cause illness-like symptoms to contact you in advance, so that they feel welcome to come to the event and to reassure other attendees if anyone is coughing or sneezing at your event.
Please do not come if you have Covid-19 or are unwell, for example with a temperature, cough, cold, vomiting or diarrhoea. This is to help keep everyone safe. This doesn’t include long-term conditions like hayfever or COPD that might cause you to cough or sneeze. If you have a condition like this, let us know before. If you are unsure if you should come, please contact us on XXXXXX
Ask attendees not to come if they have recently had close contact with someone who is unwell or tested positive with Covid-19, for example someone living in their household.
People may be asymptomatic and not realise they are unwell or infectious, so taking additional measures is advisable.
How can I put this measure in place??
Tell people in advance that there will be an online or remote joining option for your event if they cannot come in person. Encourage attendees to attend remotely if they are unwell.
Remote joining options could include a social media livestream (e.g YouTube, Instagram, TikTok, Twitch) or use online meeting software (e.g. Zoom, Google Meet).
Think about how you will make remote access meaningful and do some advance planning. Choose where to set up your camera and microphone (which could be a smartphone or laptop + webcam) and what you will put it on so that people joining remotely can get a good view and hear what’s going on.
Speak to event presenters, speakers or artists about including people joining remotely and tell them where the camera and microphone will be so they can be seen and heard.
Run a test so that you can check sound and visuals and the venue’s internet connection.
Designating an event volunteer or staff member to oversee the remote option and monitor any live feedback (e.g. livestream chat or direct messages) will help improve the remote experience and enable you to troubleshoot any problems. It will also make it easier to run any question and answer sessions that include those joining online.
How can I put this measure in place??
Tell people clearly about your event’s Covid testing policies beforehand: in the event description, booking process and in event reminders. Let people know that this policy is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable.
Include information on where people can get a test and tell people to contact you if accessing a test is going to be difficult for them. Tell people to follow the instructions on the test kit or share this guidance on how best to take a Covid test sample.
When they arrive, ask attendees to confirm that they have done a Covid-19 test beforehand.
For attendees who have forgotten, have a few tests available on the door. Ask attendees to do their test away from/outside your venue, and to return after the test’s specified wait period (usually 15 minutes).
Rapid lateral flow tests are available at Superdrug, Boots and other high-street pharmacies. They can be ordered for less than £2 per test online. Some people can get tests for free from a pharmacy.
Lateral Flow Tests are not 100% reliable in catching every case. Although they rarely read false positives, they may return false negatives. This means that some people with Covid may get a negative test result and taking other safety measures is still important.
More sensitive home testing machines, such as the Pluslife minidock, provide much more reliable test results. However, they are currently only able to test a small number of people at once, and take longer and at much higher cost compared to rapid tests. They may be suitable at events with a small number of attendees or for testing any attendees at an otherwise mask-required event who need to be unmasked.
How can I put this measure in place??
Let your attendees know in advance that you will be keeping the space well ventilated. If this involves opening doors and windows during colder weather, then tell them. Let people know that this measure is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable
Opening windows and/or doors to the outside is the simplest way to improve ventilation in an indoor space. Opening more than one window or door will help to create air flow and improve ventilation effects.
Opening them as wide as possible is best; but even cracking windows/doors open is better than nothing. If it’s impossible to keep them open throughout the event, open windows/doors regularly, e.g. for 10 minutes every hour.
A surprising number of commercial spaces have their own mechanical ventilation systems that circulate fresh air (this is not the same as air conditioning, which cools down or heats up air). Check with the venue whether they have a fresh air ventilation system and that it is in working order. Find out how to switch it on for your event.
Use your common sense to plan adequate ventilation for the size of your space and the number of people inside it. In a small venue with a handful of people present, opening one window could make all the difference. In a packed room with hundreds of people, you will need to open more ventilation routes and consider taking other safety measures.
You can use a CO2 monitor to check how well ventilated your space is. You might be surprised that your space is better naturally/mechanically ventilated than you think!
How can I put this measure in place??
Tell attendees in advance if you will be using an air purifier as one of your accessibility and Covid-19 safety measures. Tell people that this measure is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable.
Any good quality purifier is better than nothing! However, the size of your event space will determine which purifier you need, and/or how many, to process the volume of the air in your space. The most effective purifier set-up will filter all the air in your event space 5 or 6 times per hour (called “Air Changes Per Hour”). This filter comparison tool is designed to help. Smart Air offers guidance on choosing an air purifier. Most purifiers have lower power settings that reduce the noise, if quietness is important - but note that these will reduce their air processing power.
You can buy a good quality High Efficiency Particulate Air (HEPA) purifier for ~£200 upwards. These clean air calculators help you calculate Air Changes Per Hour of an air purifier and compare cost effectiveness of up to three air purifiers sold by Smart Air (we use Smart Air SA600 filters at our events). Purifiers have filters that should be replaced occasionally for continued effectiveness, so have a look at the expected filter lifespan and factor this into your budget.
You can buy a Smart Air purifier and raise money for Breathe Easy at the same time by using this Smart Air affiliate link.
Before the event, switch your purifier on to check it works and how loud it is. Think about where you will place the purifier(s) in your event space. The ideal placement is as centrally as possible where people are gathering that isn’t in the way, Make sure it’s not pushed up against furniture or walls that can obstruct airflow, and is away from fresh air sources (eg open windows/doors).
Purifiers with additional technologies such as ionization or plasma wave are largely unnecessary and could potentially create harmful byproducts in the air.
How can I put this measure in place??
Let your attendees know in advance that you will be taking measures to keep the space well ventilated by using a CO2 monitor. If this may involve opening doors and windows during colder weather, then let people know. Let people know that this measure is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable.
Use a CO2 monitor to measure how well your event space is ventilated during the event. Keep it in a central location in your event space.
Make a simple plan for your CO2 monitoring. To maintain safer levels of ventilation, try to keep the CO2 level below 800ppm. This can be done by simply opening doors or windows to the outside when your monitor shows this level. This guide and this video provide more details.
Numerous different brands of CO2 monitors are available. Aranet sells a popular model for ~£150. Smart Air has an affordable CO2 monitor (which Breathe Easy Sheffield uses) at ~£60.
How can I put this measure in place?
Clearly explain your event’s mask policies beforehand: in the event description, booking process and in event reminders. Let people know that the policy is designed to keep all attendees and event staff safe, and is particularly important for anyone who has an underlying condition or has someone close to them who is clinically vulnerable.
Using masking as a safety measure at your events is possible with good preparation. However, it’s important to be clear about what you want people to do.
You may want people to wear masks for the whole of your event. Alternatively, you can offer and promote a smaller portion of your event (eg the first hour or quieter portion of the event) where masks are required.
Wearing any mask is a better risk reduction measure than wearing no mask.
However, FFP2 or FFP3 masks (called N95/N99 in the USA) which fit your face well offer the best protection. These good quality masks are made of high level filtration material that catch airborne particles in their mesh and also attract them with an electrostatic charge. These masks are still effective when reworn, up to a maximum number of hours (varies per mask). Avoid masks with exhalation valves, which don’t filter exhaled air.
Good quality masks now come in a range of attractive colours, so you can choose masks that match your event branding.
The Facemask Store offers further guidance on masks.
Surgical and cloth masks offer limited filtration as they only block the largest particles or droplets and don’t fit as snugly on the face. They are less effective at preventing airborne illnesses like Covid-19 which are spread via much smaller aerosols and which float on the air like smoke.
Most people don’t wear masks regularly any more and there is a lot of misinformation about them, so people may benefit from a kind and gentle reminder on arrival to keep their masks on and to ensure it covers their nose and mouth well. If possible, offer better quality masks or better-fitting masks to those who arrive only with cloth or surgical masks, or with masks that clearly don’t fit properly.
Some people at your event may be Deaf or hard of hearing and may use lip reading. Options for reasonable accommodation include using a single in-person sign language interpreter (tested + unmasked), or a remote interpreter joining via video link. In smaller events, you may be able to purchase and provide masks with windows that allow the mouth to be visible. Some people may have sensory issues as part of a medical condition that prevent them from being able to wear a mask. You could create explicit exemptions on request for these individuals.
FFP2/FFP3 masks with either ear loops or head straps are available online. Masks with head straps and foam over the nose usually provide the best fit, but it’s worth trying some different styles and sizes to see which fit you best and most comfortably. You can buy masks from online retailers such as medisave.co.uk and thefacemaskstore.co.uk from 99p each, for example the Face Mask store earloop mask. You can also buy masks that enable people to see the wearer’s mouth.
If you want everyone to wear masks at your event:
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state that masks are required, not just “encouraged” or “welcome”
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include mask requirements in your event information
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tell attendees if they will be able to remove their masks to eat or drink
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tell attendees if any areas in your event space do not require masks (eg outdoor areas)
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tell attendees that masks will be available at the event
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ask attendees to inform you if they have any access issue with masks
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if you have a mask exemption for attendees with access needs, say this
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on arrival, remind attendees of the mask requirements
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offer good quality masks (respirators) to those who arrive with cloth or surgical masks
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make masks available for anyone who has forgotten
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make a plan about what you will do if people don’t wear their masks
If you want people to feel safer wearing a mask at your event:
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include Covid-19 measures prominently in your event information
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state that masks to prevent infection are “encouraged” or “welcome”
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make masks available for anyone who has forgotten
This is a non-exhaustive list of scientific evidence for each of the Covid-19 safety measures that Breathe Easy recommends for events.
This is a live evidence list. We will seek to keep it updated with robust recent evidence.
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Article: Clinical presentation of Covid-19
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Article: Symptoms of Covid-19
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Review: Comprehensive Insights Into the Multi-faceted Manifestations of COVID-19: A Narrative Review
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Review: Asymptomatic SARS-CoV-2 Infection by Age: A Global Systematic Review and Meta-analysis
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Study: Performance of Rapid Antigen Tests to Detect Symptomatic and Asymptomatic SARS-CoV-2 Infection
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Study: SARS-CoV-2 antigen lateral flow tests for detecting infectious people: linked data analysis.
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Study: Mandating indoor air quality for public buildings (paywall) PDF of article or news article about study
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Article: Ventilation Can Absentuce Exposure to Respiratory Viruses in Indoor Spaces
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Article: United States Environmental Protection Agency: Ventilation and Respiratory Viruses
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Article: Italian study shows ventilation can cut school COVID cases by 82%
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Study: SARS-CoV-2 aerosol transmission in schools: the effectiveness of different interventions
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Study: Effectiveness of HEPA Filters at Removing Infectious SARS-CoV-2 from the Air
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Expert consensus: Mandating indoor air quality for public buildings (paywall) PDF of article or news article
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Study: Ambient carbon dioxide concentration correlates with SARS-CoV-2 aerostability and infection risk or article on the study
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Guide: Unite Covid-19 Guide on Ventilation and CO2 monitoring
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Study: Masks and respirators for prevention of respiratory infections: a state of the science review or article on the study
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Study: An upper bound on one-to-one exposure to infectious human respiratory particles
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Study: Efficacy of FFP3 respirators for prevention of SARS-CoV-2 infection in healthcare workers
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Article: Upgrading PPE for staff working on COVID-19 wards cut hospital-acquired infections dramatically
Airborne transmission means airborne prevention measures like air purification, ventilation and masks are needed to prevent people breathing in the virus.
Hand sanitisers do not kill all viruses. For example, alcohol-based sanitizers are not effective against Norovirus (thorough hand washing with soap and water is required).
Like hand washing, cleaning surfaces can be helpful to prevent disease transmission in general but, for illnesses that are spread through the air, like Covid-19, measures like those listed above are more effective.
Watershed, Bristol - socially distanced cinema screenings
Site Gallery, Sheffield - masked visiting hour
Vagina Museum, London - access mornings
It is still important to stop the spread of Covid-19.
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This virus still causes death and infections can do serious internal damage even if symptoms seem mild, causing serious illness and disability (6% of infections lead to Long Covid).
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Catching Covid-19 repeatedly isn't good for your immune system. The risk of long-term health problems increases with each reinfection.
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Covid is not seasonal, it spreads throughout the year. The continued impact puts pressure on our healthcare systems, the economy, and our bodies.
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Covid safety measures make events more accessible for disabled, immunocompromised and at-risk people.
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Most Covid safety measures reduce the spread of all airborne illnesses such as flu and RSV.
Our suggested measures are based on those recommended by the World Health Organisation and used in their ARIA tool and study, developed with particle physics lab CERN to help reduce infection risk in residential, public and healthcare settings. None of the authors of this guide are qualified public health experts, but all our suggested measures are based on peer-reviewed scientific studies. You can review our list of evidence for each safety measure.
We organised our measures in line with the ‘Hierarchy of Controls’ occupational health and safety tool, which explains the relative effectiveness of different risk reduction strategies. There are five categories represented in descending order of effectiveness: elimination, substitution, engineering controls, administrative controls, and personal protective equipment (PPE).
You might wonder why the safety measures listed in this guide are not standard practice in hospitals, doctors’ surgeries, or other public spaces. That’s a good question! We think they should be. Many scientists and health experts continue to raise the alarm and call on governments to protect people better from Covid-19. But unfortunately it’s not unknown for governments to delay or deny action on public health issues - like during the HIV/AIDS crisis and the infected blood scandal. Additionally, it typically takes years for scientific evidence to translate into widely applied practice. We think that current Covid-19 policies are dangerously limited and misguided.
Compiled by Breathe Easy Sheffield’s team of volunteer co-directors. Breathe Easy Sheffield is a grassroots community organisation that exists to reduce the spread of Covid-19 through promoting and organising events with measures in place that reduce transmission risk of Covid and other similar airborne infectious illnesses, and through advocating for increased evidence-based Covid safety in public spaces.
Many people have helped us review and improve this guide. We are grateful to all our volunteer reviewers from within academia, event management teams, social justice movements and the Covid conscious and disabled communities.
If you have a question about something in this guide or any feedback, please get in touch.
Let us know if you used any of these safety measures and tell us how it went!
We also love to promote Covid-safer events, so send us your photos and event information or tag us on Instagram!
#️⃣ Find us on Instagram @breatheeasysheffield
📧 Email us at [email protected]
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Last updated: 17.08.2025