More information about infectious risk in the work environment

This includes detailed information about infectious risks in the work environment which is helpful in work environment management.

Guidance regarding the regulations on infectious risks (AFS 2018:4)

Below is guidance on the application of the Swedish Work Environment Authority's regulations on infectious risks (AFS 2018:4) when handling samples from patients with suspected or probable SARS-CoV, MERS-CoV or avian influenza H5N1. All body fluids such as respiratory secretions, tissue samples, blood, faeces and urine must be treated as infectious. Take special care with tasks that may cause splashes or aerosol. Remember not to expose other staff to a risk of infection.

1. Procedures involving no, or minor infectious risk, such as

  • Microscopy of fixed tissue samples
  • PCR examination of nucleic acid preparation
  • Electron microscopic examination of glutaraldehyde-fixated preparations
  • Pack a sample already in a surface-disinfected primary container in final outer packaging as a diagnostic sample to be forwarded to a diagnostic laboratory
  • Routines

2. Procedure that may involve a risk of infection but can still be carried out in a laboratory

  • Sampling, packing of samples in primary containers and back-up of samples
  • Distribution and dilution of samples, separation of serum
  • Preparation for tests that do not require enrichment, such as
    - microscopy
    - preparation of nucleic acid for PCR serological analysis of untreated samples
    - chemical analysis of blood, urine, respiratory secretions and more.
  • differential diagnostics with bacterial culture of agents not considered to be risk class 3 (pneumococcus, GAS, etc.).

Examples of procedures

  • Microbiological safety bench Class I or II used in laboratory
  • When centrifuging:
    - use centrifuge with safety cups
    - load and remove the safety cups in the safety bench
  • The following personal protective equipment is always used, as a complement to careful hand hygiene and disinfection:
    - properly covering protective clothing
    - protective gloves made of vinyl or nitrile rubber
  • In the case of operations that cannot be carried out in a microbiological safety bench, the personal protective equipment is supplemented with:
    - effective splash protection, such as face masks (surgical) and goggles or a visor, and, if necessary, additional barrier protection against splashes and aerosols when certain operations are carried out (such as plugging and disposal of spills)

Waste and used materials

Waste is autoclaved or sent as infectious waste according to specific procedures. The National Board of Health and Welfare has issued regulations on the management of infectious waste.

Reusable material is autoclaved before it is washed.

Laundry is autoclaved or placed in a special dissolvable laundry bag for infectious laundry.

Prerequisites and instructions

The laboratory assesses whether it is able to apply the above procedures. Written instructions regarding handling and protection in relation to these procedures must be provided. The instructions must also include measures applicable in the event of adverse events. If the laboratory determines that it is unable to take care of a sample, it is sent to a regional laboratory following agreement.

3. Transport of samples

  • Samples from the patients are sent as biological substance category B (UN3373).
  • Cultures from samples of suspected SARS-CoV, MERS-CoV or influenza virus H5N1 are sent as infectious substances category A (UN2814) to the Public Health Agency of Sweden.

The Public Health Agency’s website contains information on the transport of samples, "Pack the sample correctly".

Respirators and face masks

Difference between respirators and face masks

Respirators are designed to protect the wearer from inhaling anything harmful such as smoke, aerosols, fibres, bacteria or viruses. Requirements regarding the design of personal protective equipment are set out in Regulation (EU) 2016/425 of the European Parliament and of the Council on Personal Protective Equipment.

Surgical face masks are intended to prevent the spread of drops in the exhaled air from the wearer to the patient. Rules and standards regarding design are governed by EC Directive 93/42 on medical equipment.


There are different types of respirators.

Filter respirators: Ambient air passes through a filter. Filter respirators can be face masks, full or half masks with interchangeable filters or masks made of filter material. The latter is also sometimes called a filtering half-mask. Filter masks are sometimes fitted with exhalation valves.

Air-supplied respirators: The wearer is provided with air or oxygen from an independent source via tube or from a portable tube. A visor or hood can be fan-fed and act as a filter mask with ambient air passing through a filter or as an air-supplied respirator with air/oxygen from an independent source.

Practice handling

It is important to ensure the respirators fit snuggly. When the mask is removed, remember that it may be contaminated, and that if you wear gloves, these may be contaminated. Hand hygiene is important! Detailed instructions on how to handle respirators should be provided, as well as an opportunity to practice putting on and removing the respirator. The employer must always carry out a risk assessment to determine whether discarded filters and filter masks need to be treated as infectious waste.

Choice of protection

Respiratory protection is required to protect the wearer from airborne infection and small particles such as mould spores. Different devices can provide different levels of protection, so it is important to choose the right respiratory protection for the right occasion. The choice must always be made based on the employer's risk assessment.

Often the eyes also need to be protected, in which case a full face mask or fan-fed hood or visor provides good protection. A half mask or filter mask often needs to be supplemented with goggles with side protection or a visor.

Surgical masks are not sufficient to protect the wearer from airborne contamination, but can to some extent reduce exposure to droplet infection. It is primarily intended to take care of particles that can spread from the user's mouth and nose. For example, it is used by healthcare professionals to protect patients during surgery or in case of burns. It can also be used to protect the environment from droplet infection from a patient who sneezes or coughs. In this case, it is less appropriate for the patient to wear respiratory protection, especially if it has a valve for exhaled air, since the exhaled air does not pass through the filter. On the other hand, such a measure does not protect staff against serious airborne contamination, but rather is a complement to the personal protective equipment that staff must use.

Instructions for use

The instructions for use in Swedish accompanying each respiratory protective mask provide information about the level of protection and the substances against which the filters in the mask protect, as well as control and maintenance. Often, the supplier has additional valuable information about the product.

Regulations on respirators

Several regulations include requirements applicable to personal protective equipment that includes respirators, such as the infectious risks regulations (AFS 2018:4).

Infectious risks (AFS 2018:4), provisions (SWE)

There are special provisions on the use of personal protective equipment (AFS 2001:3).

Use of personal protective equipment (AFS 2001:3), provisions


Zoonoses are infectious agents that can spread between animals and humans and cause disease. Zoonotic infectious agents can be transmitted between animals and humans:

  • through direct contact with infected animals
  • via food or water
  • from the environment
  • via vectors such as mosquitoes and ticks.

It is important that those who come into contact with animals in their job are aware that animals can be carriers of infectious agents that can cause disease in human even if they are not sick.

More information about individual zoonoses can be found at the National Veterinary Institute (SVA) and at the Swedish Public Health Agency.

National Veterinary Institute's website, opens in new window (SWE)

Public Health Agency's website, opens in new window (SWE)

Examples of infectious agents that are zoonoses and that may occur in Sweden:

  • Salmonella bacteria and verotoxigenous Escherichia coli (EHEC) may occur in cattle. Some other salmonella types are naturally found in snakes, turtles and other reptiles. Birds can also carry salmonella bacteria.
  • Tuberculosis bacteria can be transmitted from deer in enclosures and animals in zoos.
  • Cryptosporidium is a parasite that can occur in farm animals, especially in young animals such as calves and lambs. The parasite is excreted with faeces and a human can be infected, amongst other things, through direct or indirect contact with farm animals or through contaminated water or food.
  • Campylobacter may be found in poultry, including chickens and hens. The bacterium is transmitted to humans mainly through contaminated food and water, but also through direct contact with infectious animals.
  • The parasite Toxoplasma Gondii can cause miscarriage and birth defects in pregnant women. The parasite can occur in cats, who secrete the parasite in their faeces. The parasite may also be found in other animals, including sheep and pigs. Humans can be infected, amongst other things, through contact with faeces from cats. Sheep husbandry, especially in connection with lambing, can also pose a risk of contracting the parasite. The Swedish Work Environment Authority's regulations (AFS 2007:5) on pregnant and nursing workers prohibits the exposure of pregnant women to a risk of contracting toxoplasma. More information about pregnancy and toxoplasma is available at Infpreg. More information about the prohibition is available on the penalties page.

Infpreg’s website, opens in new window (SWE)

Sanction fees

  • Rabbit fever caused by the bacterium Fransciella tularensis is found mainly in hares and small rodents. Rabbit fever can be transmitted through direct contact with infected animals, inhalation of contaminated dust, through mosquito and tick bites or ingestion of contaminated water.
  • Viral hemorrhagic fever caused by Puumalavirus is spread by voles via their saliva, urine and faeces. The infection can spread to humans either through direct contact with infected voles or through contact with contaminated dust that swirls up.
  • The bacterium Chlamydophila psittaci can cause severe respiratory disease in humans, known as parrot disease. The infectious agent is present mainly in the faeces of infected birds and can be spread to humans via dust from dried faeces in the air.
  • Contact with dust is a general risk for persons who work close to birds or who may come into contact with bird droppings and dead birds.
  • Brucellosis is sometimes called Malta fever or undulant fever when it affects humans. The disease is caused by several species of Brucella bacteria. Humans can be infected mainly through direct contact with infected animals or via food (in particular unpasteurised milk or cheese). The disease is also an important laboratory infection. Laboratory personnel have been infected when handling patient samples.
  • The tick-borne diseases Borrelia and TBE (Tick Borne Encephalitis) are examples of how infection from wild animals can be transmitted to humans via vectors.
  • The antibiotic-resistant bacterium MRSA (methicillin resistant Staphylococcus aureus) may also occur in animals. Animals can be carriers of the bacteria even if they are not sick. The MRSA incidence in animals in Sweden is lower than in many of our neighbouring countries. MRSA is spread mainly through direct contact, and therefore good hygiene practices when working with animals, including in pigsties and in slaughterhouses, is important. Read more about MRSA and antibiotic resistance on the Main risks of infection page.

Main risks of infection

Preventing microbiological growth

It is useful to have some knowledge of the properties of microorganisms when working with the prevention of health problems due to microbiological activity.

Moisture, nutrition and heat are needed for growth

Microorganisms need moisture, nutrients from organic matter and moderate heat to grow. The moisture may come from condensation or may be present in the organic material from which the microorganisms are nourished.

In nature, microorganisms break down dead plants and animals, which releases nutrients for new organisms. The organic material that a microorganism needs can therefore range from living plants and animals to microscopic, broken-down parts or food residues from humans.

Many microorganisms grow best in temperatures between 10 and 40 °C. The optimal temperature varies between individual microorganisms. Mold fungi and bacteria that break down organic matter in the soil usually prefer temperatures around 20 °C. Infectious agents usually grow best at 35-37 °C.

Prevent growth by removing growth conditions

In many workplaces, it is an effective strategy to ensure that nutrients and good growth conditions are not available to microorganisms. Sometimes cleaning is sufficient, but in some cases other measures are required.

Some examples of measures preventing growth of microorganisms:

  • Be sure to prevent moisture problems by checking pipes for leakages and that the building is weatherproof.
  • Cleaning with effective detergents is often sufficient to remove dirt and kill microorganisms.
  • Use of disinfectants to kill bacteria in laboratories and industries.
  • Control of temperature and ventilation in the indoor environment to avoid condensation.
  • Prevent growth of Legionella bacteria by building pipe systems in real estate that prevent static lukewarm water in "dead ends" and pipe loops.

Procedures for handling samples from patients with suspected SARS, MERS or influenza A H5N1

The information below, developed in cooperation with the Swedish Public Health Agency, can be used by employers as a basis in risk assessments identifying measures that may be needed to comply with the requirements of the Swedish Work Environment Authority's regulations in this area. As always, it is the employer's obligation to carry out a risk assessment, which in this case must be in writing and form the basis for the employer's decision on measures to prevent exposure to the infectious agent.

Avian influenza caused by influenza virus H5N1 can be transmitted from birds to humans in case of close contact with infected birds. Avian influenza of type H5N1 in humans has been declared a disease which is a public health hazard under the infectious disease legislation. In spring 2003, outbreaks of severe acute respiratory disease (SARS) occurred mainly in Asia. SARS also spread between people, mainly to health professionals and relatives. SARS, which is caused by a coronavirus, is no longer spreading, but is classified as a public health threat. MERS-CoV is another airborne virus that occurs mainly in the Middle East and can cause serious illness.

Avian influenza A/H5N1 is so severe that, until more is known, the precautionary principle should be applied and the infectious agent should be treated as a risk class 3 organism. The same applies to MERS-CoV. SARS-CoV is classified as risk class 3. Cultivation as well as management of cultures or procedures involving concentration of suspected risk class 3 organisms must be reported to the Swedish Work Environment Authority in accordance with the regulations on infectious risks (AFS 2018:4).

Infectious risks (AFS 2018:4), provisions (SWE)

Specific procedures must also be in place for sampling and handling of human or animal samples. The infectious risks regulations (AFS 2018:4) apply to all work with infectious agents and in all work environments where workers can be exposed to contact with infectious agents.

Last updated 2024-01-08