Section 6: Safety in biotechnology
6.1 Information for all teachers, including safety in non-specialist rooms
Teachers planning for safety in biotechnology should have a thorough knowledge of the area. If this is not the case, teachers should seek advice from a specialist. This is especially important when culturing micro-organisms, where teachers should have some training in microbiological techniques. Each school is required to develop, implement, and manage health and safety policies and procedures, which must be approved by the Board of Trustees. These policies and procedures are expected to be adhered to in addition to implementing the recommendations of this manual.
Before commencing work with students, teachers need to undertake an initial risk analysis of the process for the work so that they can identify potential hazards in relation to:
- the people involved, such as students, resource personnel, and the intended end users of the outcomes that are produced (including considering cultural and ethical issues)
- the materials and equipment used, including energy sources and wastes
- the environment, particularly in separating food and non-food items for storage, during the production of the final outcome.
In good technological practice, students should also be made aware of the importance of risk analysis. This process should become an integral part of their classroom practice.
When hazards are identified, risks can often be minimised by incorporating appropriate procedures.
Many investigations involving biotechnology can be carried out successfully in general classrooms with typical facilities for year 1–6 students. The multi-purpose nature and architecture of general classrooms, however, presents some health and safety concerns.
It is desirable to have a separate area in the school for biotechnological investigations or to have an area of the classroom set aside for the duration of the project. Investigations involving biotechnology are often ongoing, necessitating material being set up over lengthy periods of time, which can create problems with care, hygiene, and security.
Schools using specialist materials for biotechnological investigations must have effective policies and practices for storing, handling, and disposing of these materials. This includes a policy for disposing of unwanted micro-organisms and chemical residues, both of which are classed as hazardous wastes.
When working with living material, it is important to prevent cross-contamination with pathogenic (disease-causing) organisms. In some situations, it may be necessary to establish a workspace where sterile conditions can be maintained.
The following guidelines should be followed to minimise the risk of contamination:
- Only work with material of known biological characteristics.
- Never work with unknown living material.
- Never culture pathogenic (disease-causing) organisms.
- Prevent contamination of culture material by establishing and following sterile work procedures.
- Dispose of material carefully and thoroughly, ensuring that living material cannot reproduce.
All electrical equipment and installations must comply with local authority and electrical safety regulations. A registered electrician must carry out all wiring and electrical maintenance except for replacing a fuse or wiring an extension cord. The following defects must be investigated immediately and corrected by a registered electrician:
- machinery or equipment that gives electric shocks, however slight
- overheated switches or plugs
- sparking or spluttering from cords or plugs
- broken or frayed leads or cords
- broken switches.
Electrical Regulations require that all electrical appliances including portable power tools, isolating transformers, and RCDs (Residual Current Devices) used in school workshops or specialist rooms are:
- inspected and tested before use
- inspected after being repaired
- inspected at intervals not exceeding 12 months
- tagged at inspection – each piece of equipment should be tagged, and all inspections should be carried out by a registered electrician or an approved power tool agent
- recorded in a school register of all electrical equipment.
Teachers should encourage students to examine all electrical equipment before it is used, including all plugs, sockets, extension leads, and other electrical equipment used for biotechnology activities, such as bread makers, dehydrators, computer data-logging equipment, and digital balances. This also applies to any electrical equipment borrowed from various sources for short periods of time. Careful positioning of electrical extension leads and equipment within the classroom can minimise the potential for accidents.
There are a number of teaching situations where animals could be included in a biotechnological setting. Students may wish, for example, to develop a biotechnology convenience pet food and trial its suitability with certain animals.
Schools should have an animal ethics policy that meets the legal requirements of the Animal Welfare Act 1999, or any other subsequent legislation, and any procedure that involves interfering with the normal physiological, behavioural, or anatomical integrity of any vertebrate animal requires approval from an animal ethics committee.
Section 6 of the Animal Welfare Act defines “animal”, and the policy paper The Use of Animals in Research, Testing and Teaching: Users Guide to Part 6 of the Animal Welfare Act 1999 explains this section.
When animals are used in any technology investigation, students must adhere to the Code of Ethical Conduct for the Use of Animals in school programmes and apply to their local animal ethics committee before starting any such investigation.
In some instances, biotechnology can be approached through the area of food technology, as in the production of yoghurt, bread, and cheese. Where this is the case, including taste testing, the work should be carried out in the area of the school or classroom designated for food technology. This area should be kept separate from areas set aside for other aspects of biotechnology. Any biotechnological investigation linked with food technology poses additional safety concerns, and teachers should also comply with the safety guidelines relating to food technology (Section 5).
Many biotechnology investigations make use of a range of micro-organisms. The major groups of micro-organisms are algae, protozoans, fungi, bacteria, and viruses, and the two groups most commonly used in school biotechnology are fungi and bacteria. Teachers need to take particular care and attention when students work with micro-organisms.
Only named and identified micro-organism species from a reliable source should be used. Teachers or students should never culture unknown species, especially bacteria.
Brewer’s and baker’s yeast available from supermarkets, yoghurt-forming bacteria cultured from existing yoghurt, or fungi cultured from cheese are all good starting points. A list of micro-organisms suitable for use in schools can be found in Appendix 4.
The Code of Practice for School Exempt Laboratories should be consulted when culturing micro-organisms. Teachers should be aware of and follow this Code when collecting, handling, culturing, and disposing of micro-organisms. When culturing micro-organisms, biotechnology teachers should be aware of the following guidelines:
- Do not use human or animal sources of micro-organisms.
- Do not take samples from toilets and toilet areas, including sinks and door handles.
- Do not take samples from rubbish bins and drinking taps.
- Cultures originating from skin surfaces may be used only if the cultures remain sealed.
- Use sterile swab sticks to inoculate plates.
- Wash hands thoroughly after working with micro-organisms.
- Label each culture clearly with the student’s name, the date, and the source of the sample.
- If Petri dishes are used to culture micro-organisms, cover and seal them to prevent contamination and the spread of spores. Use adhesive tape or cling film to seal these dishes, and incubate the cultures upside down.
- To pipette culture samples, use only automated pipettes, never mouth-operated pipettes.
- Transfer microbiological material from one culture to another in sterile conditions. Always wear safety glasses and gloves.
- Incubate microbiological cultures at temperatures of 25°C or below to avoid the risk of culturing pathogenic organisms.
- If using glassware for fermentation investigations, never seal it, because the build-up of pressure could cause an explosion. Either lightly plug containers with cotton wool or cover them with aluminium foil. If using plastic drink bottles as simple fermenters, as in the production of ginger beer, be aware that considerable pressure can build up in sealed bottles to the point of explosion.
Many fungi are significant in the biotechnology and food industries. Care should be taken when collecting or handling fungi because many (including toadstools, mushrooms, moulds, and puffballs) may be poisonous. Spores released from many species can also cause allergic reactions in some people.
Bioremediation (waste management)
Before teachers set up small-scale experiments to illustrate waste breakdown by micro-organisms, they must be aware that unknown pathogens could be present. Small-scale fermenters must be designed to ensure that gas pressure does not accumulate, as the build-up of flammable biogas could be dangerous.
Clean-up and disposal of biotechnological wastes
Many waste materials from biotechnology are classed as hazardous wastes, so they must be disposed of in a way that does not endanger people or the environment. Chemical wastes should be disposed of in accordance with local bylaws.
All microbiological cultures must be sterilised before disposal. This can be achieved by using one of the following methods:
- heating in a pressure cooker for at least 20 minutes
- soaking in a 10 percent bleach solution for three days
- incinerating (with the incinerator very hot).
The person responsible for disposing of microbiological cultures needs to be trained. This person could be a teacher or an ancillary staff member, but not a student.
If a culture is spilled, a teacher wearing disposable gloves must deal with it immediately. Cover the broken container and/or spilled culture material with a cloth soaked in a disinfectant of 10 percent bleach (100 ml [millilitres] of bleach in a litre of water) for at least 10 minutes. Then clear away the spillage using disposable paper towels and a dustpan. Place the contaminated material in a separate bag for disposal, along with the gloves, and disinfect the dustpan. Note: Household bleach solutions may not be strong enough to ensure sterilisation.
Biotechnological investigations using plants may include working with whole plants, plant parts, or plant cells. Because many plants are poisonous, teachers should help students identify those that are safe to use in their investigations. Care must also be taken with the development of plant extracts because many known drugs and poisons originate from them. During their investigations, students may make use of plants of cultural significance. They should be made aware of the significance associated with these plants, for example, harakeke, heritage potato, and various ferns.
Many kinds of biotechnological investigations may involve simple tissue culture practice. Several practices that students can carry out illustrate basic techniques that have been developed further in industry. Many tissues such as cauliflower curd, carrot, pine seeds, or willow leaf can be simply propagated from small pieces of material, either in fluid or gel media.
6.2 Additional safety in specialist areas
Most safe practice for biotechnology education of students in years 10–11 is outlined in 6.1 above.
Teachers of students in years 12–13 need to consider a number of safety practices for using specialist equipment, chemicals, and procedures. Recent New Zealand science, technology, and biology curriculum statements recognise the growing significance of biotechnology, particularly micro-organism biotechnologies and genetic modification, in our everyday lives, such as in food derivatives, medicines, pharmaceuticals, and environmental remediation. Senior secondary school students are encouraged to carry out increasingly sophisticated investigations. Facilities, equipment, chemicals, enzymes, micro-organisms, and advice are readily available from a number of supply firms.
There are a growing number of specialist school facilities for teaching biotechnology. These facilities, however, can often be shared, and vary considerably in their design and available equipment. Teachers should carefully consider where equipment is placed, because many (such as fermentation and growth investigations) are ongoing while other groups of students and teachers are using the room for other purposes. For security and safety, other staff and students should be made aware of any ongoing investigations.
Equipment often found in specialist classrooms could include controlled plant-growth facilities, autoclaves (for example, pressure cookers), incubators, fermenters (often modified plastic bottles), refrigerators, dehydrators, and computers, all of which require regular general and electrical maintenance. Regular checking by teachers should ensure that these are maintained in a safe state.
Teachers who are unsure about any practice should obtain information and instruction from other local teachers or science experts before attempting any unfamiliar procedure or using unfamiliar equipment.
Many chemicals associated with biotechnological investigations are toxic. Copper sulphate, a chemical commonly used as a fungicide and for growing crystals, is poisonous and can cause serious eye damage. Student access to it should be limited and supervised. Refer to the Code of Practice for School Exempt Laboratories for information about substances and chemical procedures that are forbidden in schools.
Bacteriogenetic methods and practices
When using micro-organisms in teaching biotechnology at senior levels, teachers need to be vigilant about obtaining safe species and strains from reliable supply sources. Generally, soil bacteria, such as Bacillus subtilis, are relatively safe as are genetically-crippled strains of Escherichia coli. The fungus Saccharomyces cerevisiae (baker’s yeast), including its many strains, is not only very safe but can be used in a variety of investigations.
A number of bacteria, such as Serratia marcescens, have known carcinogenic properties and should not be used; neither should the gut bacteria Escherichia coli unless genetically crippled, with records kept of the use, including certificates and strain numbers. There is concern about using any Escherichia coli as it can cause food poisoning, and Escherichia coli 0157 can cause kidney failure and death. When culturing micro-organisms, take care that no one inhales the reproductive spores. These spores, in particular from the cultures of Mucor or Penicillium, can affect people with asthma and allergies. Do not use Aspergillus, such as Aspergillus niger, which will grow inside lungs. Aspergillus flatus produces a mycotoxin that can cause food poisoning. Student laboratory practice should keep to that detailed in the Code of Practice for School Exempt Laboratories.
In schools, the safest method for inducing mutations in micro-organisms is by using ultraviolet (UV) radiation. Students should wear UV-protective glasses.
Only named and identified micro-organism species from a reliable source should be used. Teachers or students should never culture unknown species, especially bacteria.
Investigations using bacteriophages, such as those that attack Escherichia coli and lactic acid bacteria, are harmless both to humans and to the environment.
A common technique for investigations that isolate deoxyribonucleic acid (DNA) involves using enzymes and sodium dodecyl sulfate (SDS). In industry, extracted DNA is often precipitated by using chloroform in a fume cupboard. However, as chloroform is a banned substance in schools (see the Code of Practice for School Exempt Laboratories), a safer procedure involves isolating DNA after treatment with washing-up liquid, followed by the enzyme lysozyme and then ethanol. An alternative is to autolyse dried yeast in an alkaline solution at 40°C, filter, concentrate by dialysis, and precipitate with ethanol.
Chemicals that are supplied by manufacturers in powder form, such as enzymes and SDS, need careful handling because of their effects on living tissue. An experienced teacher or technician should prepare these reagents in a force-ventilated space, such as a fume cupboard. Always wear a face mask when handling powdered enzymes. Specialist biotechnology facilities may contain electrophoresis equipment. DNA from bacteria can be broken into fragments with restriction enzymes and then separated electrophoretically in a gel. Methylene blue is the recommended safe stain for this application. If choosing another stain to allow the fragments to be viewed, take great care because the stain nipogen is a known carcinogen and ethidium bromide is banned in schools (see the Code of Practice for School Exempt Laboratories).
All school biotechnological investigations that involve transgenic DNA manipulation will, by law, require approval from Environmental Protection Authority (EPA) New Zealand. This organisation has the role of approving all new genetically modified organisms in New Zealand.
The practice of students inserting genes into plants by using a gene gun, to illustrate disease resistance or herbicide resistance, is currently outside any school programme. However, students could visit industries where such practices occur, and natural methods of DNA transformation, such as gall formation by the common vector Agrobacterium, can be easily induced in a variety of plant tissue in the laboratory. Agrobacterium can be obtained by extracting live samples from active galls on such trees as willow or lacebark.
Teachers in any doubt about a planned activity involving transgenic procedures can seek advice from the Biotechnology Learning Hub.
Disposing of hazardous waste
Section 6 of the Code of Practice for School Exempt Laboratories should be consulted for a list of how to dispose of hazardous substances. Some substances must be sent to a specialist waste operator. If a liquid or hazardous waste operator is used, ensure the operator has been certified by the Liquid and Hazardous Waste Certification Council. WasteMINZ has a list of certified operators. Using a certified operator will provide assurance that hazardous wastes are being dealt with in a responsible manner.