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How do you stay safe, and keep others safe, when working with microorganisms and chemicals in a biotechnology laboratory?

Describe the hazards in a biotechnology laboratory and the biosafety measures used to control them

A focused answer to the O-Level outcome on biosafety. The main laboratory hazards, biosafety levels, safe working practices, and the safe disposal of biological waste.

Generated by Claude Opus 4.88 min answer

Reviewed by: AI editorial process; not yet individually human-reviewed

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  1. What this dot point is asking
  2. The answer
  3. Examples in context
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What this dot point is asking

This outcome asks you to describe the hazards in a biotechnology laboratory and the biosafety measures that control them. It is the practical, safety-focused partner to aseptic technique: there, the aim was a pure culture; here, the aim is to keep people and the environment safe. Examiners reward measures paired with reasons.

The answer

The main hazards

A biotechnology laboratory has several kinds of hazard:

  • Biological hazards. Microorganisms, some of which can cause disease, and the risk of them spreading or being released.
  • Chemical hazards. Reagents that may be irritant, toxic or flammable.
  • Physical hazards. Heat from flames and autoclaves, sharp objects, and electrical equipment.

Biosafety levels

Laboratories are classified into biosafety levels according to how dangerous the microorganisms they handle are. Higher levels require stricter containment, such as sealed cabinets and controlled airflow. School and basic laboratories work only with low-risk, harmless microorganisms at the lowest level.

Safe working practices

Key biosafety measures protect the worker and others:

  • Wear personal protective equipment (laboratory coat, gloves) and tie back long hair, to protect skin and clothes.
  • Wash hands before and after work, to avoid carrying microorganisms in or out.
  • Use aseptic technique and disinfect surfaces, to prevent contamination and spread.
  • Do not eat, drink or touch the face, to avoid taking microorganisms into the body.
  • Deal with spills immediately, cleaning them up with disinfectant.

Safe disposal of waste

Biological waste (used cultures, plates) contains live microorganisms. If thrown away untreated, these could escape or infect people. So the waste is sterilised first, for example by autoclaving with steam under pressure, which kills the microorganisms and their spores, before it is disposed of.

Examples in context

Example 1. A high-containment laboratory. Laboratories that study dangerous pathogens use high biosafety levels with sealed cabinets, controlled airflow and strict procedures, so the microorganisms cannot escape. It shows containment scaled to match a serious hazard.

Example 2. Autoclaving used plates. At the end of a practical, all used agar plates and cultures are autoclaved before being thrown away. This routine step ensures that even harmless cultures are not released alive, embedding safe disposal as standard practice.

Try this

Q1. State two biosafety measures that protect a worker handling microorganisms. [2 marks]

  • Cue. Wearing protective equipment such as a laboratory coat and gloves, and washing hands before and after work (not eating or drinking is also acceptable).

Q2. Explain why biological waste is sterilised before disposal. [2 marks]

  • Cue. It contains live microorganisms that could escape or infect people; sterilising kills them so the waste is safe to dispose of.

Q3. Name a method used to sterilise contaminated laboratory waste. [1 mark]

  • Cue. Autoclaving (steam under pressure at high temperature).

Exam-style practice questions

Practice questions written in the style of SEAB exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

Original6 marksDescribe the safety measures that should be taken when working with microorganisms in a biotechnology laboratory, and explain why each is important.
Show worked answer →

Examiners want practical biosafety measures, each with a reason.

Wear personal protective equipment such as a laboratory coat and gloves, and tie back long hair, to protect the skin and clothes from contamination by microorganisms or chemicals. Wash hands before and after work to avoid carrying microorganisms in or out.

Use aseptic technique, working near a flame and disinfecting surfaces, to prevent contamination of cultures and to stop microorganisms spreading. Do not eat, drink or touch the face, to avoid taking microorganisms into the body.

Handle cultures carefully to avoid spills and aerosols, and clean up any spills with disinfectant immediately. Sterilise contaminated equipment and dispose of biological waste safely, for example by autoclaving before disposal, so that live microorganisms are not released.

What markers reward: protective equipment and hand washing (protect the worker), aseptic technique and disinfecting surfaces (prevent spread), no eating or drinking (avoid ingestion), dealing with spills, and sterilising or autoclaving waste before disposal (prevent release), each with a correct reason.

Original4 marksExplain why biological waste from a biotechnology laboratory must be sterilised before it is disposed of, and describe one method of doing so.
Show worked answer →

The answer should explain the risk and give a sterilisation method.

Biological waste, such as used cultures and plates, contains live microorganisms. If it were thrown away untreated, these microorganisms could escape into the environment or infect people handling the rubbish, which could be harmful, especially if any are disease-causing.

Sterilising the waste first kills the microorganisms, making it safe to dispose of. One method is autoclaving, using steam under pressure at a high temperature, which kills the microorganisms and their spores. The treated waste can then be disposed of safely.

What markers reward: the point that waste contains live microorganisms that could escape or infect people if not treated, and a valid sterilisation method such as autoclaving with steam under pressure that kills the microorganisms before disposal.

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