Classifying Biological Hazards

Biological hazards are classified using the United Nations (UN) classification system for the purposes of the carriage of dangerous goods. Dangerous goods are assigned UN class numbers and proper shipping names according to their hazard classification to clearly identify the dangerous article or substance.

Dangerous Goods

Dangerous goods are liquid or solid substances and articles containing them that have been classified according to an internationally agreed UN classification system. Dangerous goods are assigned to different classes depending on their predominant hazard in the following list.

  • Class 1 Explosives
  • Class 2 Gases
  • Class 3 Flammable liquids
  • Class 4 Flammable solids
  • Class 5 Oxidizing substances
  • Class 6 Toxic substances (6.1 Toxic substance or 6.2 Infectious substance)
  • Class 7 Radioactive substances
  • Class 8 Corrosive substances
  • Class 9 Miscellaneous dangerous goods

The UN approved classification under class 6 for toxic substances is UN class 6.2 infectious substances.

Biological Hazards and Infectious Substances

The UN classification is UN class 6.2 infectious substances under the class 6 group. Infectious substances are defined as substances which are known or are reasonably expected to contain pathogens which can cause disease in humans, animals or plants. The transport category must first be established to enable the correct packaging and labeling procedures required for the safe transport of biological hazards. Biological hazards are divided into the following categories for the purposes of carriage of dangerous goods.

  • Category A Infectious substances affecting humans or humans and animals
  • Category A Infectious substances affecting animals
  • Category B Biological substances
  • Exempt substances
  • Genetically modified organisms
  • Biological substances which are not dangerous goods

There are additional requirements are in place for animal pathogens and plant pathogens and pests in the UK. See the DEFRA website for further details.

Category A

Infectious substances which are capable of causing permanent disability, life threatening or fatal disease to exposed humans or animals are included in category A. Exposure occurs when an infectious substance is released outside of the protective packaging resulting in physical contact with humans or animals. Infectious substances meeting these criteria which cause disease in humans or both in humans and animals must be assigned to UN 2814. Infectious substances which cause disease only in animals must be assigned to UN 2900. Examples of substances that meet these criteria are given in the WHO indicative list of infectious substances in category A. Details of the category A indicative list can be found in the HSE Biological agents: Managing the risks in laboratories and healthcare premises and the WHO Guidance on the transport of infectious substances to determine if your biological hazard is category A. The table of indicative infectious substances included in category A is not exhaustive. The indicative list includes all biological agents classified as HG4 in the ACDP Approved list of biological agents, many HG3 and some HG2 biological agents. Infectious substances including new or remerging pathogens which do not appear in the table but which meet the same criteria must be assigned to category A. In addition if there is doubt as to whether or not a substance meets the criteria then it must be included in category A. Assignment to UN 2814 or UN 2900 must be based on the known medical history and symptoms of the source human or animal, endemic local conditions, or professional judgement concerning individual circumstances of the source human or animal. The proper shipping name for UN 2814 is "Infectious Substance, Affecting Humans" and for UN 2900 is "Infectious Substance, Affecting Animals".

Category B

Infectious substances which are not capable of causing permanent disability, life threatening or fatal disease to exposed humans or animals are included in category B. These infectious substances do not meet the criteria for inclusion in category A. Infectious substances meeting these criteria must be assigned to UN 3373. Assignment to UN 3373 must be based on the known medical history and symptoms of the source human or animal, endemic local conditions, or professional judgement concerning individual circumstances of the source human or animal. The proper shipping name for UN 3373 is "Biological Substance, Category B".

Genetically Modified Organisms

Genetically modified organisms may be classified as category A or B if they are an infectious substance or exempt substances if they are not infectious substances. Genetically modified organisms may also be classified as hazardous in some other way other than as infectious substances. The GMO should first be assessed to determine if it is capable of causing disease in humans or animals then it should be classified as category A or B as appropriate and UN 2814, UN 2900 or UN 3373 (eg activity class 2 or 3 GMO). Certain GMO or non GMO nucleic acids may also be infectious substances in their own right (eg infectious virus clone). If the GMO is not infectious for humans or animals but is still able to alter animals, plants or other microorganisms in a way that does not occur naturally then it must be classified for transport purposes as UN class 9 miscellaneous dangerous goods (eg activity class 1 GMO). Genetically modified organisms meeting these criteria must be assigned to UN 3245. The proper shipping name for UN 3245 is “Genetically Modified Organisms” or “Genetically Modified Microorganisms”. Genetically modified organisms that are not infectious and not able to alter animals, plants or other microorganisms are not considered hazardous for transport but they should be properly packaged so they do not leak during transport and also be appropriately labelled so as to not to give rise to safety or security concerns of the material.

Biological Materials and Samples

Biological materials and samples containing microorganisms or cultures of microorganisms should be classified as category A or B depending on whether it meets the criteria for infectious substances. Clinical materials sourced from humans or animals including tissues, blood, body fluids and other materials being transported for research or diagnostic purposes should be assigned to category A or B depending on the known medical history or source of the material. Most clinical material should be classified as category B infectious substances unless it is known or reasonably believed that the material contains category A infectious substances. DNA, RNA, plasmids, proteins or antibodies etc are not generally considered hazardous for transport but such material should be properly packaged so they do not leak during transport. Specimens of human and animal origin should be packaged and transported in such a way as to protect those engaged in transportation from the risk of infection. Biological and clinical waste generated by the University is transported for disposal by an external contractor in compliance with the relevant transport and waste regulations. Please note that many biological materials may also be subject to import or export controls in addition to the national and international carriage of dangerous goods regulations.

Exemptions

There are certain types of biological substances which are not subject to the regulatory requirements because of the low hazard they represent unless they meet the criteria for inclusion in another class. These include non pathogenic microorganisms, substances where pathogens have been neutralized or inactivated, environmental samples including food and water which are not considered to pose a significant risk of infection, certain types of biological materials dried blood spots collected for screening tests, blood or blood components collected for the purposes of transfusion or transplantation and any tissues or organs intended for use in transplantation. Human or animal materials where there is minimal likelihood that pathogens are present are exempt from the regulations provided they are packaged in a way so as to prevent leakage during transport and labelled with the appropriate words "Exempt Human Specimen" or "Exempt Animal Specimen". A judgement has to be taken on the likelihood of pathogens being present in the samples and materials based on any relevant evidence such as the source or the presence of infectious diseases in the population.