What are the types of biological hazards

Biological agents

One distinguishes

  1. Bacteria (e.g. staphylococci, streptococci, tuberculosis pathogens
  2. Prions (e.g. pathogens of Creutzfeldt-Jakob disease)
  3. Viruses (e.g. hepatitis viruses, herpes viruses)
  4. Human endoparasites (e.g. tapeworms and roundworms, malaria pathogens)
  5. Mushrooms (e.g. molds)

Animals (with the exception of endoparasites) and plants, organic dusts (wood dusts, feed dusts), ectoparasites such as mites and ticks, free nucleic acids and plasmids (components of cells), metabolic products and other products of plant or animal origin (animal hair, feathers, Food and ingredients).

Why are biological agents dangerous?

Microorganisms (including genetically modified ones), cell cultures, viruses, spores and unconventional agents (prions) can cause infectious diseases, allergies or toxic (poisonous) effects.

There are 4 risk groups based on the risk of infection:

  • Substances of risk group 1: generally do not cause disease in humans
    Examples: methane bacteria, bifidobacteria in the dairy, acetic acid bacteria.
  • Substances of risk group 2: can cause illness in humans and pose a risk to workers.
    Examples: Legionella, tetanus pathogens, polioviruses
  • Substances of risk group 3: can cause serious illness in humans and pose a serious risk to workers.
    Examples: anthrax pathogens, tuberculosis pathogens, AIDS pathogens
  • Substances of risk group 4: can cause serious illness in humans and pose a serious risk to workers. The risk of spreading it to the population is high, and effective prevention or treatment is usually not possible.
    Examples: Ebola viruses, Lassa viruses

As part of the evaluation, employers must assign the biological agents to the risk groups according to their infection potential (Section 40 (4) ASchG). Substances in risk groups 2 to 4 are considered dangerous, substances in risk group 1 are generally not considered dangerous. Since the allergenic and / or toxic potential of the substances is not taken into account in the classification, when using substances of risk group 1 it is nevertheless necessary to check whether they can be hazardous to health.

Biological uptake can take place in different ways:

  • through the airways
  • over the skin and mucous membranes
  • via the digestive tract

The pathogens can be transmitted through the air (droplet infection), through contact with contaminated surfaces or objects (smear infection) or the ingestion of contaminated food.

When does the regulation of biological agents apply?

The Ordinance on Biological Agents is only applicable if employees have to work with substances or at facilities that could contain biological agents.

The determination of whether biological agents are being used must be made when determining and assessing the hazards according to Section 41 of the ASchG.

If the use is intended, the use of the biological agent is the actual purpose of the activity (e.g. in research laboratories).

In the event of unintentional use, contact with the biological agents is a side effect of the tasks that are actually in the foreground (e.g. in waste management or in health care).

From the determination of whether there is intended or unintentional use with biological agents, employers can derive various risk prevention measures.

When identifying and assessing hazards, groups of people who are particularly in need of protection, such as adolescents or pregnant or nursing mothers, must be taken into account.

You can find more information in the brochure Biological Agents - Classification, Protective Measures, Industry Examples (PDF, 1.1 MB).

Types of biological agents


Microorganisms are different organisms that are characterized by their small size. Due to their great adaptability, they are able to successfully settle in all areas of the environment. They produce around 75 percent of the entire biomass on earth and are of great importance for biological material and energy cycles.

Nevertheless, even in the 21st century, microorganisms represent a problem that should not be underestimated as the cause of diseases in humans, animals and plants.

Viruses, bacteria, fungi and human endoparasites can cause serious, even chronic diseases that can lead to death.


Bacteria are unicellular organisms with different shapes without a nucleus, nuclear membrane or mitochondria. The cell wall determines the size and shape of the bacterium. In contrast to fungi, bacteria are mobile.

The optimum growth of medically important bacteria is between 18 ° - 45 ° Celsius. Minimum and maximum ranges range from 2 ° and 50 ° Celsius.

Most species prefer a pH value in the neutral range around pH 7, lactobacilli have an optimum at pH 5, and cholera Vibrios at pH 9.

Most medically important bacteria can grow in the presence or in the absence of atmospheric oxygen (energy is obtained through breathing and fermentation).

Bacteria play an important role in occupational safety, especially as infectious agents and toxin producers (endo- and exotoxins).

The bacteria multiply by dividing them transversely. The generation time (time of doubling) ranges from a few minutes (Clostridium species) to several hours (Mycobacterium tuberculosis).


Viruses are small, infectious particles made up of nucleic acids (RNA, DNA), proteins (proteins) and possibly also lipids (fats).

The capsid (protein shell) determines the shape of the virus. Viruses do not have their own metabolism and are multiplied by the infected host cell. They are therefore intracellular parasites. Viruses can only survive for a short time outside the host cell and cannot multiply on their own. The risk of infection outside of another living cell or organism is therefore of relatively short duration.


Deoxyribonucleic acid is a nucleic acid in the form of a right-handed double helix.

It contains the genetic information for biological development in cells and some viruses. In international and scientific usage, deoxyribonucleic acid is referred to as DNA (desoxyribonucleic acid), and in German-speaking countries it is also referred to as DNS.


Parasites are organisms (plants or animals) that live temporarily or permanently at the expense of other living beings - so-called hosts - to satisfy needs (food, reproduction, etc.).

They stay permanently on the (ectoparasites) or in the (endoparasites) body of the host and live on the host's body substance or on the food ingested without killing their host. The host organism does not benefit from them, it is damaged to a greater or lesser extent. Plant parasites include mistletoe and summer root, animal parasites include tapeworms, leeches and fleas.

Parasites, such as worms or insects, are the largest pathogens against which the immune system has to act. Worms can be microscopic, but they can also be several meters long.

They are mostly transmitted from animals to humans. Sources of infection are foods that are contaminated with worm eggs or animal feces that contain worm eggs, e.g. vegetables fertilized with sewage sludge.

Another route of transmission is the consumption of infected meat, e.g. pork, which contains trichinae.

Endo- or internal parasites live inside their host. They colonize cavities, the blood or the tissue of various organs. Extracellular endoparasites live outside cells (e.g. tapeworms and roundworms).

Intracellular endoparasites mainly live within host cells, but are therefore classified as microorganisms.

Many endoparasites can be found both extra- and intracellularly during their life cycle.


Fungi are among the most widespread organisms on earth.

They colonize a wide variety of organic or inorganic substrates and, because of their metabolic physiological possibilities, are significantly involved in the metabolism of substances. With 96%, they make up the largest proportion of biological particles in the air. The medically important mushrooms (apart from the poison mushrooms) are among the micromyzetes (fruiting bodies can only be seen with a magnifying glass or microscope).

The reproduction and spreading takes place through spores or vegetatively through spreading (mycelia or mycorrhizae).

Some metabolic products (Penicillium, Saccharomyces cerevisiae, Candida kefyr and others) are said to have healing (penicillin) or at least health-promoting effects (in kefyr, beer, wine). Other fungi are considered to cause infectious diseases (Cryptococcus, Aspergillus) or to cause allergies (Penicillium, Aspergillus, Cladosporium).

Cladosporium appears to be the most common trigger for mold allergies in Northern Europe. Its clinical relevance is pronounced. The presence of sensitization to Cladosporium is associated with a higher risk of acute asthma attacks and appears to correlate with the severity of the asthma.

Some mushrooms are characterized by the formation of toxins (toxins, the so-called mycotoxins) such as aflatoxin and ochratoxin (from Aspergillus and other genera).

The classification of mushrooms is different. The DHS system (dermatophyte-yeast-molds) was set up for medical needs.

Cell cultures

Cell cultures are isolated single cells that are grown and propagated in laboratories under certain conditions.

They come from plants, animals or humans and are used in the pharmaceutical industry, the food industry, as a substitute for animal experiments, for vaccine production and the like.

Cell cultures can contain pathogens or toxins from the donor organism or they can cause allergies.

Unconventional agents

Unconventional agents, e.g. prions (small proteins), are pathogens that cause transmissible spongiform encephalopathies, such as the bovine disease BSE (bovine spongiform encephalopathy) and similar diseases in humans (Creutzfeldt-Jakob disease) or animals (scrapie in sheep and goats).

In all of these diseases, the brain is decomposed like a sponge.

Prions are very resilient. They can withstand almost all disinfectants, extreme heat and even have a low level of residual infectivity after they have dried out.

Types of use of biological agents

A distinction is made between intended and unintentional use.

In the course of the evaluation, it must be determined whether there is an intended or unintentional use.

Intended use

With the intended use, working with a biological agent is the actual purpose of the activity (Section 1 (3) VbA, Section 40 (4) ASchG).

It is known that

  • biological agents are present,
  • where they occur in the work process and
  • which working materials are involved.

Intended Use Areas:

  • Scientific research in the field of microbiology, biochemistry, medicine
  • Laboratories, such as microbiological analysis, bacteriological-serological diagnosis, research
  • Food industry, such as the production of yoghurt or cheese, microbial production of all kinds of additives
  • Pharmaceutical industry, such as vaccine production, production of various drugs

The following criteria must be included in the determination and assessment:

  1. The risk group of biological agents
  2. Possible routes of infection
  3. The possible allergens or toxic effects due to the resulting metabolic products or the presence of the organism itself.
  4. Type and frequency of activity
  5. Diseases that have already occurred or diseases that may be attributable to the use of the biological agent.

Unintended use

In the event of unintentional use, there is usually no (exact) knowledge of the identity of the biological agents used. If the assignment to a risk group is still possible, there is an obligation to make this assignment.

In order to assess the dangers and risks for employees in the event of unintentional use, use must also be made of experience with comparable activities, the state of the art in science and technology, as well as illnesses of employees that have already become known (e.g. hepatitis or TBC infections in nursing staff Tapeworms, dog and fox tapeworms in agricultural workers) and appropriate protective measures must be specified.

In the case of unintentional use, the purpose of the activity is not to use a biological agent (Section 1 (4) VbA, Section 41 ASchG).

However, exposure can occur due to the materials used, the work environment, or contamination.

Areas with unintended use:

  • Waste management, such as household waste dumps, sewer works, sewage treatment plants, waste sorting, hospital waste
  • Health care, such as doctor's offices, infection wards, hospital laundry
  • Timber industry, sawmills, like moldy wood
  • Agriculture, such as working with grain or hay
  • Leather processing
  • Restoration work, such as pictures, books, furniture
  • Dealing with animals or with products of animal origin such as rendering plants, slaughterhouses
  • Use of cooling lubricants
  • Maintenance / cleaning of air conditioning systems, humidifiers and the like
  • Biofilters, such as changing the material

Measures to prevent danger

As part of the identification and assessment of the hazards ("evaluation"), measures for hazard prevention must be specified for the intended and unintentional use of biological agents.

Protective measures to be taken when using biological agents can be found generally in the Employee Protection Act (ASchG) or in more detail in the Ordinance on Biological Agents (VbA).

Measures for intended use:

  • Obligation to replace or use in a closed system
  • Special hygiene regulations
  • Special disinfection and cleaning regulations
  • Protective / work clothing
  • Offer vaccinations
  • Additional protective measures (structural or technical)
  • Area identification
  • Obligation to report to the labor inspectorate
  • Informing employees Written instructions
  • Offer medical examinations

Measures in the event of unintentional use:

  • Special hygiene regulations
  • Special disinfection and cleaning regulations
  • Protective / work clothing
  • Offer vaccinations
  • Special instruction obligation
  • Written instructions if necessary
  • Offer medical examinations

Directory of employees

If group 3 or 4 biological agents are used, employers must keep a list of employees who are exposed to these agents in accordance with Section 47 ASchG.

Needlestick injuries

Needlestick injuries are dangerous, common, expensive and avoidable!

Stab and cut injuries are one of the greatest dangers for healthcare workers.

In March 2010, the Council of the European Union therefore passed Directive 2010/32 / EU on the prevention of injuries from sharp / pointed instruments in the hospital and health sector, which came into force in June 2010.

The implementation in Austrian law took place with the needle prick ordinance - NastV, which came into force on May 11, 2013.

Further information on the NastV can be found in the decrees Information on the Needle Prick Ordinance - NastV (PDF, 0.3 MB) and the Needle Prick Ordinance in the Care Sector (PDF, 0.1 MB).

The EU directive applies to all employers in the hospital and healthcare sector and regulates, among other things. the following obligations:

  • Definition and implementation of safe procedures for handling sharp / pointed medical instruments and contaminated waste and for their disposal and introduction of appropriate disposal procedures as well as clearly marked and technically safe containers for the disposal of sharp / pointed medical instruments and injection devices.
  • Avoid unnecessary use of sharp instruments by changing procedures based on the results of the risk assessment and providing medical instruments with built-in safety and protection mechanisms.
  • Prohibition of replacing the protective cap on the used needle (prohibition of RECAPPING).

The aim is therefore to improve the safety and health protection for employees in the health care system through an integrated approach to assessing and avoiding risks and to reduce the number of stab and cut injuries (especially the number of needlestick injuries) by using safe instruments.

Needlestick injuries or injuries caused by pointed / sharp instruments carry the risk of transmitting infectious diseases such as hepatitis B, hepatitis C and HIV for those affected.

Incidence of needlestick injuries

Needlestick injuries must be reported to the Allgemeine Unfallversicherungsanstalt (AUVA) if the inability to work is longer than three days. It is believed that 80 to 90% go unreported. It remains unclear how many needlestick injuries there are in Austria.

Last change on: 02/22/2021