BIOLOGICAL HAZARDS Why are biological materials hazardous Biological

BIOLOGICAL HAZARDS

Why are biological materials hazardous? Biological materials are potentially more hazardous than even some of the most hazardous chemicals because micro-organisms canØ multiply very rapidly Ø are contagious ( they can be transferred from one person to another or even from animals to humans. ) Ø can change their form to prevent removal by the immune system Ø may produce toxic waste products which cause death or disease. Ø are often extremely small and hence difficult to detect.

Types of Biohazardous agents There are four general classes of biological hazardous agents Ø aetiological or infectious agents - These are biological materials which produce infectious disease. Ø oncogenic or cancer causing agents. Ø recombinant DNA from genetic engineering Ø hazardous natural products.

Risk assessment in the biological laboratory Besides the normal risk assessment in any laboratory, there are some additional considerations for biological laboratories and facilities that handle biohazardous materials. Go to www. ascc. gov. au and find the Code of Practice for the control of work related exposure to hepatitis and HIV (blood borne viruses. [NOHSC: 2010(2003)]

Sterilisation and Decontamination Procedures. Decontamination - rendering an item or area free from organisms by killing them. Sterilisation - the total destruction of any living species by the use of chemical or physical agents. Sanitation - is the reduction in the number of living species in an area to an accepted safe level. Disinfection - refers to the process of removing organisms (generally by chemical means ) which have the potential to cause infection. All organisms are not necessarily killed, and spores may remain viable. Microbiostasis - the arresting of growth and multiplication of organisms without killing them. Contact time - is the time required for a sterilisation or decontamination to kill a micro-organism when it is in direct contact.

There a wide variety of procedures used for sterilisation and decontamination – Ø heat sterilisation ( including steam, dry oven and flame methods) Ø Incineration Ø the use of chemical disinfectants. Ø treatment with radiation.