Have you ever been confused about what PPE (protective personal equipment) will protect you and when you should wear it? OSMS has compiled research from twelve sources to give the public a comprehensive view of what kinds of PPE should be used to minimize the risk of COVID-19 infection during different types of activities.

How is COVID-19 spread?

COVID-19 spreads between people primarily through contact with infectious respiratory droplets which are released from the mouth or nose when an infected person coughs, sneezes, or speaks.[1] The virus will spread when these infectious droplets make contact with someone else’s mouth, nose, or eyes. Infection is most likely to occur when people are in close contact (within 6 feet) of an infectious person, especially in indoor environments with poor ventilation.[2] COVID-19 may also be spread by coming into contact with common, shared surfaces that have been contaminated by infectious respiratory droplets, like door handles, tabletops, elevator buttons, and pin pads, for example.[3] Additionally, the more time someone spends around an infected person, the higher their risk of acquiring COVID-19.

What is PPE and why use it?

 Personal protective equipment (PPE) is worn to protect the wearer from exposure to contaminants, and the term can refer to masks, respirators, face shields, gloves, goggles, gowns, and other equipment. Correct PPE use has the potential to block transmission of contaminants from bodily fluids (including respiratory droplets).[4] PPE should always be used alongside other infection control measures, such as hand-washing and the use of hand sanitizers, to reduce the spread of infection.[5] Effective use of PPE also includes knowing how to properly put on (donning) and take off (doffing) each item, and correctly disposing of these items to further reduce contact with contaminants.[6]

Different situations present different risks, and can require different kinds of PPE based on the time spent in certain environments, the type of environment, and the type of activity. Open Source Medical Supplies has compiled this guide on the proper use of PPE, given the risks of different kinds of situations, in order to help the public understand the role PPE has in preventing COVID-19 transmission in everyday situations.

PPE Used for Different Types of Risk

Examples of Risky Activities

Low Risk

  • Opening the mail
  • Getting restaurant takeout
  • Pumping gasoline
  • Playing tennis
  • Going camping
  • Going for a walk, run, or bike ride with others
  • Playing golf

  • Staying at a hotel for two nights
  • Grocery Shopping
  • Sitting in a doctor’s waiting room
  • Going to a library or museum
  • Eating in a restaurant (outside), or at someone’s house
  • Walking in a busy downtown
  • Spending an hour at a playground
  • Going to a hair salon
  • Working in retail/cashier
  • Eating in a restaurant (inside)
  • Playing team sports
Higher Risk
  • Traveling by plane
  • Hugging or shaking hands when greeting a friend
  • Working as a server
  • Working out at a gym
  • Going to an amusement park, movie theater, music concert
  • Attending a religious service with 500+ worshippers

Clinical Risk

Treating Patients
  • Treating COVID-19 Patients directly
  • Checking in patients who are ill
  • Talking with family and friends of patients who are ill
Treating ICU Patients
  • Intubating Patients
  • Treating ICU Patients

Source: Texas Medical Association Risk Assessment

Click on the Scenario to find out more about what kinds of PPE to use!

Low Risk: Walking Outside

Moderate Risk: Taking Public Transit

High Risk: Flying on an Airplane

Clinical Risk: Treating a Positive Patient

Low-Risk Activities:

Low Risk


Click on the numbers to learn more!

Large uncrowded rooms that are well- ventilated and socially-distant outdoor areas are relatively low risk. Low-risk activities include outdoor walks, hiking, exercising, and simple quick errands. These kinds of activities require minimal or no contact or conversations with others. It is still important to wear a cloth covering anytime you leave your house, even for a short while in order to protect others.

When you must remove your mask or return home after low-risk activities, remember to wash your hands or sanitize them immediately, before touching your face.

  • Outdoors with proper social distancing, 6 feet apart.
  • Minimal contact with other people for less than 15 minutes. [8][9]
  • Minimal direct face-to-face conversation.
  • Inside, in a large, well-ventilated area
  • Inside, in an enclosed location for short periods of time, with proper social distancing and mask wearing

Moderate Risk


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Spending hours in indoor areas (even if people are socially distant and wearing masks) and high-traffic/crowded outdoor areas are a moderate risk. Gatherings of groups, indoors or outdoors in socially-distant groups are also a moderate risk.

The most significant change to PPE one can make to minimize moderate risk is changing the type of face mask worn. While surgical masks and cloth face coverings protect other people if you are sick, they will not protect you from someone else’s respiratory droplets, even outdoors. It’s important to wear a close-fitting filtering mask, such as a cloth mask with a filter or a filtering mask like an N95, in order to effectively prevent infection.

Door handle openers and other personal tools can be used to reduce your frequency of touching common surfaces like handles. Remember to use hand sanitizer after taking off your PPE, and before touching your face.

  • Inside a large, enclosed, well-ventilated location up to 45 min, with proper social distancing and with most people wearing masks (based on a study of hairdressers interacting with masked clients [10]).
  • Around large groups of people wearing masks; check your state’s guidelines for acceptable group sizes 
  • Outdoors in small, socially-distant groups of people that are actively talking or shouting
  • High-traffic areas where many people actively pass-through

High Risk


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Indoor areas with poor air circulation, and any crowded areas, are high risk even if masks are being worn. Tasks and activities that require regular and constant exposure to new people, or that feature extended contact with people where no social distancing is possible, are also high risk.

When engaging in high-risk activities, effective protection requires several layers of PPE. Filtering masks are still the most important element of PPE, but face shields, transparent partitions, and goggles can further prevent infection from respiratory droplets. Gloves are appropriate when touching contaminated surfaces regularly (like handling cash or using shared door handles), as long as you take care to properly remove gloves afterward and not touch your face while wearing them. You may want to use different elements of the PPE listed below, depending on the type of activity you are conducting.

Note that face shields and sneeze guards/transparent partitions may be used in addition to a filtering face mask, but are not sufficient to protect against infection and must always be used in addition to face masks. They are most effective when talking and interacting with a large number of people who may or may not be wearing masks. Face shields can be interchanged with sneeze guards/transparent partitions as the situation demands.

  • Inside an enclosed location with poor ventilation, or for extended periods of time like a full workday, even with proper social distancing and mask-wearing.
  • In large crowded groups of more than 20 people, whether indoors or outdoors, in which people are talking or shouting.
  • Extremely high-traffic areas with regular exposure to new contacts for extended periods of time.
  • Extended contact with people when no social distancing is possible, whether masked or not, indoors or out.
  • Gatherings of larger than 250 people [11].

Clinical Risk


Hospitals and medical facilities all have individual and specific requirements and policies regarding appropriate use of PPE. The information provided aims to explain the full range of PPE used to limit exposure to COVID-19, but is in no means a recommendation. When traveling to a location where you are extremely likely to be in contact with someone COVID-19 positive, please first refer to the established institutional guidelines first.

  • Working in a clinical setting where patients are treated.
  • Several hours indoors with close contact with other people.
  • Risk of direct exposure to patients infected with COVID-19.
  • Potential extended exposure to contaminated surfaces.

Click on the numbers to learn more!

Additional PPE not shown:

Stay Safe

Read our other COVID-19 guides.