📚 A-Level Biology: Key Points of Experimental Risk Assessment | A-Level 生物：实验风险评估要点
In A-Level Biology, practical work is essential, but every experiment carries some degree of risk. A clear and systematic risk assessment is not just a paperwork requirement—it is a vital skill that keeps you, others, and the environment safe. This article summarises the key points you need to know for CIE A-Level Biology.
在 A-Level 生物中，实验操作至关重要，但每一项实验都带有一定程度的风险。清晰且系统的风险评估不仅是文书要求，更是保护自己、他人和环境安全的关键技能。本文为你梳理 CIE A-Level 生物考试中必须掌握的风险评估要点。
1. Hazard vs Risk | 危险与风险的区别
A hazard is anything that has the potential to cause harm, such as a chemical, a microorganism, or a sharp object. Risk is the likelihood that harm will occur under the specific conditions of the experiment, combined with the severity of that harm. For example, a Bunsen burner is a hazard; the risk of a burn depends on how it is used, the distance from flammable materials, and whether a heat-proof mat is present.
危险是指任何可能导致伤害的事物，例如某种化学品、微生物或尖锐物品。风险是指在特定实验条件下，伤害发生的可能性及其严重程度的组合。例如，本生灯是一种危险；烫伤的风险则取决于使用方法、与易燃材料的距离，以及是否使用了隔热垫。
2. Why Risk Assessment Matters in Biology | 为什么风险评估在生物学中至关重要
Biological experiments often involve living organisms, enzymes, and chemicals that may be hazardous. A proper risk assessment helps you anticipate problems, choose safer alternatives, and respond correctly in an emergency. In examinations, you are expected to identify hazards and explain control measures with scientific reasoning.
生物实验常常涉及活体生物、酶以及可能有害的化学品。完善的风险评估帮助你预判问题、选择更安全的替代方案，并在紧急情况下做出正确反应。考试中，你应当能够指出危险并解释相应的控制措施及其科学依据。
3. Biological Hazards | 生物危害
Biological hazards include microorganisms (bacteria, fungi, viruses), blood and other body fluids, animal tissues, and enzymes. They can cause infection, allergic reactions, or toxic effects. Risk levels depend on the microorganism’s pathogenicity, route of transmission, and concentration.
生物危害包括微生物（细菌、真菌、病毒）、血液和其他体液、动物组织以及酶类。它们可能引起感染、过敏反应或毒性效应。风险水平取决于微生物的致病性、传播途径和浓度。
- Microorganisms – use sterile techniques, disinfect work surfaces, and never mouth-pipette.
- 微生物——使用无菌操作，对工作台面消毒，绝对禁止用口吸取液体。
- Blood or tissue samples – treat all as potentially infectious; wear gloves and eye protection.
- 血液或组织样本——应视为潜在传染源；佩戴手套和护目镜。
- Enzymes – some, like trypsin, can irritate skin or eyes; avoid inhalation of powders.
- 酶——某些酶如胰蛋白酶可刺激皮肤或眼睛；避免吸入粉末。
4. Chemical Hazards | 化学危害
Chemicals used in biology labs include stains, buffers, acids, bases, and solvents. They may be corrosive, toxic, irritant, or flammable. For example, iodine solution can stain skin, Benedict’s solution contains copper sulfate which is harmful, and ethanol is highly flammable.
生物实验室中使用的化学品包括染色剂、缓冲液、酸、碱和溶剂。它们可能具有腐蚀性、毒性、刺激性或易燃性。例如，碘液会染色皮肤，本尼迪特试剂含有有害的硫酸铜，乙醇则高度易燃。
| Chemical | 化学品 | Hazard | 危害 | Control | 控制措施 |
|---|---|---|
| Ethanol | 乙醇 | Flammable | 易燃 | Keep away from naked flames | 远离明火 |
| Benedict’s solution | 本尼迪特试剂 | Harmful if swallowed | 吞食有害 | Wear gloves; do not eat or drink in lab | 戴手套；实验室内禁止饮食 |
| Acid/alkali | 酸/碱 | Corrosive | 腐蚀性 | Use dilute solutions; wash spills immediately | 使用稀溶液；立即冲洗泼洒物 |
5. Physical Hazards | 物理危害
Physical hazards arise from equipment and procedures. Broken glass, sharp scalpel blades, hot water baths, centrifuges, and electrical equipment all present risks. These hazards often cause cuts, burns, or electric shocks.
物理危害来自设备和操作过程。破碎玻璃、锋利的解剖刀片、热水浴、离心机和电器设备都存在风险。这些危害常导致割伤、烫伤或电击。
- Glassware – inspect for cracks before use; dispose of broken glass in a designated sharps bin.
- 玻璃器皿——使用前检查是否有裂缝；破碎玻璃应放入指定的利器盒。
- Heat sources – use tongs or heat-resistant gloves; never leave a Bunsen burner unattended.
- 热源——使用夹钳或耐热手套；不可让本生灯无人看管。
- Centrifuges – balance tubes correctly; never open the lid until the rotor has stopped.
- 离心机——正确配平离心管；转子完全停止前切勿打开盖子。
6. Five Steps of a Risk Assessment | 风险评估的五个步骤
A standard risk assessment follows a structured sequence. You should be able to apply this to any practical procedure in your exam.
标准风险评估遵循有结构的顺序。你应该能在考试中将其应用于任何实验操作。
- Identify the hazards – list all substances, organisms, and procedures that could cause harm.
- 识别危险——列出所有可能造成伤害的物质、生物体和操作。
- Decide who might be harmed and how – yourself, classmates, or others nearby.
- 确定谁可能受到伤害及方式——自己、同学或附近其他人。
- Evaluate the risk and decide on precautions – consider likelihood and severity.
- 评估风险并决定预防措施——考虑可能性和严重程度。
- Record the findings and implement them – write the assessment and follow it.
- 记录发现并实施——写下评估结果并遵照执行。
- Review and update – especially if the procedure or materials change.
- 审查与更新——尤其在操作或材料改变时。
7. Personal Protective Equipment | 个人防护装备
Personal protective equipment, or PPE, is a key control measure but should be used alongside other safety actions. Wearing it is not optional in most school laboratories.
个人防护装备（PPE）是关键的控制措施，但应与其他安全行动同时使用。在大多数学校实验室中，穿戴 PPE 不是可选事项。
- Lab coat – protects skin and clothing from splashes and flames.
- 实验服——保护皮肤和衣物免受泼溅和火焰伤害。
- Safety goggles – protect eyes from chemicals and flying debris.
- 护目镜——保护眼睛免受化学品和飞溅碎片的伤害。
- Gloves – use nitrile or latex gloves when handling biological samples or corrosive chemicals.
- 手套——处理生物样本或腐蚀性化学品时使用丁腈或乳胶手套。
- Closed-toe shoes – protect feet from spills and broken glass.
- 不露趾鞋——保护脚部免受泼溅和碎玻璃伤害。
8. Aseptic Technique and Microorganism Safety | 无菌技术与微生物安全
Culturing microorganisms requires special precautions to avoid contamination and infection. The goal of aseptic technique is to keep the culture pure and to prevent the release of microbes into the environment.
培养微生物需要特别防护以避免污染和感染。无菌技术的目标是保持培养物纯净，并防止微生物释放到环境中。
- Wipe the bench with disinfectant before and after the experiment.
- 实验前后用消毒剂擦拭实验台。
- Flame the inoculating loop before and after transferring bacteria.
- 接种环在转移细菌前后需灼烧灭菌。
- Work near a Bunsen flame to create an upward convection current that reduces airborne contamination.
- 在本生灯火焰附近操作，利用上升热气流减少空气中的污染。
- Label and seal cultures securely; never open sealed petri dishes.
- 清晰标记并密封培养物；切勿打开已密封的培养皿。
- Autoclave all used cultures and contaminated equipment before disposal.
- 所有用过的培养物和被污染的设备在废弃前必须高压灭菌。
9. Chemical Safety and COSHH | 化学品安全与 COSHH
In the UK, the Control of Substances Hazardous to Health (COSHH) regulations require schools to assess the risks of hazardous chemicals and biological agents. Even if you are studying outside the UK, understanding these principles helps you classify hazards and choose appropriate controls.
在英国，《有害健康物质控制法规》（COSHH）要求学校评估危险化学品和生物制剂的风险。即使你在英国以外学习，理解这些原则也有助于你分类危害并选择适当的控制措施。
Common hazard symbols you must recognise include:
你必须认识常见危害符号，包括：
- Irritant / Harmful – may cause skin or eye irritation.
- 刺激性 / 有害——可能引起皮肤或眼睛刺激。
- Toxic – may cause serious health effects or death.
- 有毒——可能造成严重健康影响甚至死亡。
- Corrosive – can destroy living tissue on contact.
- 腐蚀性——接触时可破坏活体组织。
- Flammable – easily catches fire.
- 易燃——容易着火。
- Oxidising – may intensify a fire.
- 氧化性——可能加剧火势。
10. Waste Disposal and Decontamination | 废物处理与去污
Correct waste handling prevents injury and environmental pollution. Different types of waste require different disposal routes.
正确的废物处理可防止伤害和环境污染。不同类型的废物需要不同的处理途径。
| Waste type | 废物类型 | Disposal method | 处理方法 |
|---|---|
| Broken glass / sharp items | 碎玻璃 / 尖锐物品 | Sharps bin, sealed and labelled | 利器盒，密封并标记 |
| Microbial cultures | 微生物培养物 | Autoclave before disposal | 高压灭菌后处理 |
| Chemical solutions | 化学溶液 | Follow local rules; never pour down sink unless instructed | 遵循本地规则；未经指示切勿倒入水槽 |
| Biological tissue | 生物组织 | Seal in biowaste bag; incinerate if required | 密封于生物废物袋；必要时焚烧 |
11. Emergency Procedures | 应急程序
Knowing what to do in an accident is part of risk assessment. Your examiner may ask you to describe the correct response to common laboratory incidents.
知道事故发生时该怎么做是风险评估的一部分。考官可能会要求你描述对常见实验室事件的正确反应。
- Chemical spill – alert a teacher, wear gloves, use spill kit or absorbent material.
- 化学品泼洒——告知老师，戴手套，使用防泄漏套件或吸附材料。
- Fire – switch off gas and electricity, use a fire blanket or extinguisher, evacuate if needed.
- 着火——关闭燃气和电源，使用灭火毯或灭火器，必要时疏散。
- Cut with broken glass or scalpel – allow bleeding briefly, clean with antiseptic, cover with sterile dressing, seek first aid.
- 被玻璃或刀片割伤——让伤口短暂流血，用消毒剂清洁，覆盖无菌敷料，寻求急救。
- Eye contamination – use an eyewash station immediately, holding the eye open and rinsing for several minutes.
- 眼睛污染——立即使用洗眼器，撑开眼睛并冲洗数分钟。
- Injury from microorganisms – clean the wound thoroughly and report the incident; follow school infection-control policy.
- 微生物导致的伤害——彻底清洁伤口并报告事件；遵守学校感染控制政策。
12. Practical Exam Tips | 实验考试提示
In the CIE practical exam, you will not always be asked for a full written risk assessment, but you may need to suggest safety precautions, explain why they are needed, or identify hazards from a diagram. Always connect the precaution to the specific hazard.
在 CIE 实验考试中，不总是要求你写出完整的风险评估，但你可能需要提出安全预防措施、解释其必要原因，或从图中识别危险。一定要将预防措施与具体危险联系起来。
- Read the question carefully; underline any substance, temperature, or equipment that is hazardous.
- 仔细阅读题目；标出危险的物质、温度或设备。
- Use precise vocabulary: “wear safety goggles” is better than “be careful”.
- 使用精确词汇：“佩戴护目镜”优于“小心点”。
- Justify every precaution with a biological or chemical reason, e.g., “to prevent enzyme denaturation” or “to avoid cross-contamination”.
- 用生物学或化学原因为每项措施提供依据，例如“防止酶变性”或“避免交叉污染”。
- If a risk is already controlled, do not write it again. Focus on the remaining significant risks.
- 如果风险已被控制，不要重复写。聚焦于剩余的重要风险。
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