Hazards & Safety Precautions (Cambridge (CIE) IGCSE Biology): Revision Note

Identifying hazards in experiments

• A hazard is something that could cause harm

• A risk is the chance that the harm will happen

• You may be asked to describe the hazards in a specific experiment

• Common hazards in biology experiments include:

  • scalpels and knives used to cut specimens, which could cut fingers

  • hot water-baths and Bunsen burners, which could cause burns or scalds

    • Note: a water-bath at 37 °C is warm, not hot, so it is not a burn hazard

  • chemicals, such as hydrochloric acid, which could irritate or damage the eyes or skin

  • enzymes and some plant tissues, which could cause a skin reaction

  • broken glassware, which could cause cuts

• When you describe a hazard, say what could happen, not just what the hazard is

• Name the hazard itself, not the precaution, e.g. "the scalpel could cut the skin", not "wear gloves"

• Examiner reports show that students lose marks by:

  • describing a precaution when the question asks for a hazard

  • naming hazards that are not really present, e.g. a water-bath that is not hot enough to burn

Matching the safety precaution to the hazard

• A safety precaution is something you do to reduce the risk from a hazard

• Every precaution must match a hazard in that experiment

• Write your answer as a chain:

hazard → what could happen → precaution

• For example:

hydrogen peroxide → splash into the eyes → wear safety goggles

• Other examples include:

  • Scalpels can cause cuts to fingers or hands, so cutting should be done away from the body on a hard, flat surface

  • Hot water-baths can cause scalds or burns to the skin, so tongs or test-tube holders should be used to move hot tubes

  • Enzyme solutions can cause skin reactions or irritation, so laboratory gloves should be worn

    • Note: laboratory gloves protect against chemicals, but they do not protect fingers from a scalpel blade

  • Bunsen burners can cause long hair to catch fire, so long hair should be tied back

• General precautions that do not match a hazard in the experiment will not be credited

• Examiner reports show that students lose marks by:

  • giving general precautions, such as gloves, goggles and lab coats, that do not match a hazard in the investigation

  • saying only "be careful" or "get an adult to help"