Proper ways of handling, storing and disposing of chemicals for SS 1

Class: SS 1
Term: First Term
Week: 8
Age: 15 years
Duration: 60 minutes
Subject: Chemistry
Curriculum Theme: The chemical world
Focal competence: Acquiring information on safety and ways of preventing hazards associated with chemicals
Key competencies/values: Communication; Information Literacy
Skills:

• Working safely in the laboratory

Previous Lesson: Chemical Hazards, Common Laboratory Hazards and Laboratory Safety Rules
Topic: Laboratory Safety Rules And Guidelines
Subject Matter: Proper ways of handling, storing and disposing of chemicals, Safety rules in handling and storage of chemicals

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Identify safe ways of storing and retrieving chemicals in the laboratory.
• Describe proper ways of disposing chemicals.

Affective Domain

• Observe safety rules in handling chemicals in school laboratory.

Psychomotor Domain

• Recite chemistry laboratory safety rules/pledge.
• Work safely in a chemistry laboratory.
• Demonstrate proper methods of handling chemical safely.

Reference Materials

The following resources were used in planning this lesson:

• 2025 New Revised Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• A suitable Chemistry textbook for SS 1
• The HeadTeacher Scheme of work For The New Revised Senior Secondary Education Curriculum (SSEC)

Instructional Materials

The teacher will teach this lesson with the aid of:

• The school laboratory
• Packages and bottles of Laboratory Chemicals (for demonstration of labels)
• Video clips on chemicals, associated hazards and safety precautions
• A chart on chemical Hazards and their symbols
• CD or DVD player
• Personal Protective Equipment (PPE) such as lab coats, safety goggles, gloves
• Designated chemical waste containers

Rationale for the Lesson

This lesson is essential for equipping students with the knowledge and practical skills to work safely in a chemistry laboratory. Understanding proper chemical handling, storage, and disposal prevents accidents, protects health, and ensures environmental safety. It also fosters a responsible attitude towards scientific experimentation and adherence to safety protocols.

Prerequisite/Previous Knowledge

Students should have a basic understanding of what chemicals are and the general purpose of a science laboratory.

Lesson Content/Board Summary

Proper ways of handling, storing and disposing of chemicals

Safe Handling of Chemicals

Handling chemicals safely is paramount to preventing accidents and injuries in the laboratory. It involves understanding the properties of chemicals and using appropriate techniques and protective gear.

1. Read Labels Carefully: Always read the label on a chemical container before use to understand its hazards, concentration, and specific handling instructions.
2. Use Personal Protective Equipment (PPE):
   1. Lab Coats: Wear a lab coat to protect clothing and skin from chemical splashes.
   2. Safety Goggles: Always wear safety goggles to protect eyes from splashes, fumes, and projectiles.
   3. Gloves: Use appropriate gloves (e.g., nitrile, latex) when handling corrosive, toxic, or irritating chemicals.
3. Avoid Direct Contact: Never taste, smell directly, or touch chemicals with bare hands. Use a wafting motion to smell chemicals if necessary.
4. Proper Pouring Techniques: Pour chemicals slowly and carefully to avoid splashes. Hold the label of the bottle against your palm to prevent drips from obscuring it.
5. Work in a Fume Hood: Use a fume hood when working with volatile, toxic, or strong-smelling chemicals to prevent inhalation of hazardous fumes.
6. Never Return Unused Chemicals: Do not return unused chemicals to their original containers to prevent contamination.
7. Clean Up Spills Immediately: Report any chemical spills to the teacher immediately and follow proper clean-up procedures using appropriate spill kits.

Safe Storage of Chemicals

Proper storage of chemicals is crucial for maintaining laboratory safety and preventing reactions between incompatible substances.

1. Clear Labelling: All chemical containers must be clearly labelled with the chemical name, concentration, date of receipt, and hazard warnings. Never use unlabelled chemicals.
2. Segregation of Incompatible Chemicals: Store chemicals according to their hazard class and compatibility. For example:
   1. Acids should be stored separately from bases.
   2. Flammable materials should be stored in designated flammable cabinets.
   3. Oxidizers should be kept away from organic materials and reducing agents.
   4. Corrosives should be stored below eye level.
3. Appropriate Containers: Store chemicals in their original, appropriate containers. Ensure lids are tightly sealed to prevent evaporation or contamination.
4. Cool, Dry, and Ventilated Areas: Store chemicals in cool, dry, well-ventilated areas, away from direct sunlight or heat sources.
5. Secure Storage: Keep highly hazardous or sensitive chemicals in locked cabinets.

Proper Disposal of Chemicals

Chemical waste must be disposed of correctly to prevent environmental pollution and harm to individuals.

1. Never Pour Down the Drain: Do not pour chemicals down the sink unless specifically instructed by the teacher and confirmed safe for disposal via the drainage system.
2. Separate Waste Streams: Collect chemical waste in designated, clearly labelled waste containers based on their chemical properties (e.g., halogenated organic waste, non-halogenated organic waste, heavy metal waste, strong acids/bases).
3. Neutralisation: Neutralise acidic or basic waste solutions before disposal if permitted and instructed.
4. Solid Waste: Place solid chemical waste (e.g., filter paper with chemical residues, broken glass) in designated solid waste bins, not general waste bins.
5. Follow School/National Guidelines: Adhere strictly to the school’s and national environmental protection agency’s guidelines for chemical waste disposal.

Chemistry Laboratory Safety Rules

Adhering to general safety rules is fundamental to working safely in any chemistry laboratory.

1. No Eating, Drinking, or Chewing Gum: Never eat, drink, or chew gum in the laboratory to prevent ingestion of chemicals.
2. No Horseplay: Avoid running, pushing, or any form of horseplay in the laboratory.
3. Report Accidents and Spills: Report all accidents, spills, or injuries to the teacher immediately, no matter how minor.
4. Know Emergency Procedures: Be aware of the location and proper use of safety equipment such as fire extinguishers, fire blankets, eyewash stations, safety showers, and first aid kits. Know the emergency exit routes.
5. Wash Hands: Always wash hands thoroughly with soap and water before leaving the laboratory.
6. Dress Appropriately: Tie back long hair, avoid loose clothing, and wear closed-toe shoes in the laboratory.
7. Follow Instructions: Always follow the teacher’s instructions carefully and do not perform unauthorised experiments.
8. Keep Work Area Tidy: Maintain a clean and organised workspace.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Observation, Video Presentation.

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Engaging

Teacher’s Activity: The teacher asks students about the importance of safety in any environment, then narrows it down to the science laboratory. The teacher introduces the topic: “Proper ways of handling, storing and disposing of chemicals.”

Pupils’ Activity: Pupils respond to questions and listen attentively to the introduction.

Learning Point: Importance of lab safety

Step 2: Understanding Chemical Hazards and PPE

Time: 10 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher uses the chart on chemical hazards and their symbols to explain different types of hazards (e.g., corrosive, flammable, toxic). The teacher then demonstrates and explains the importance of Personal Protective Equipment (PPE) like lab coats, safety goggles, and gloves.

Pupils’ Activity: Pupils observe the chart, listen to explanations, and identify different hazard symbols. They also observe the demonstration of PPE.

Learning Point: Chemical hazard recognition

Step 3: Safe Handling Techniques

Time: 10 minutes

Teaching Skill: Demonstration/Guided Practice

Teacher’s Activity: The teacher guides students to watch a short video clip on how to handle chemicals safely, focusing on reading labels, proper pouring, and avoiding direct contact. The teacher then demonstrates these precautions using empty chemical bottles or safe substances.

Pupils’ Activity: Pupils watch the video, observe the teacher’s demonstration, and discuss the techniques shown. Some pupils may practice handling empty bottles under guidance.

Learning Point: Safe chemical handling techniques

Step 4: Safe Storage of Chemicals

Time: 10 minutes

Teaching Skill: Explanation/Discussion

Teacher’s Activity: The teacher explains the principles of safe chemical storage, including clear labelling, segregation of incompatible chemicals, and appropriate storage conditions (cool, dry, ventilated). The teacher points out examples of proper storage in the lab.

Pupils’ Activity: Pupils listen to the explanation, ask questions, and observe the storage arrangements in the laboratory.

Learning Point: Proper chemical storage methods

Step 5: Proper Disposal of Chemicals

Time: 8 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains the importance of proper chemical disposal and demonstrates how to use designated waste containers for different types of chemical waste. The teacher stresses never pouring chemicals down the drain without instruction.

Pupils’ Activity: Pupils listen to the explanation and observe the different types of waste containers and their labels.

Learning Point: Correct chemical waste disposal

Step 6: Laboratory Safety Rules and Pledge

Time: 7 minutes

Teaching Skill: Recitation/Reinforcement

Teacher’s Activity: The teacher presents the general chemistry laboratory safety rules (e.g., no eating, no horseplay, report spills, know emergency exits). The teacher leads the students in reciting a simple chemistry laboratory safety pledge.

Pupils’ Activity: Pupils listen to the rules, ask questions, and recite the safety pledge after the teacher.

Learning Point: Adherence to safety rules

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. Mention two safe ways of storing chemicals in the laboratory.
2. Describe one proper way of disposing of chemical waste.
3. Why is it important to wear safety goggles in the lab?
4. State two general safety rules for the chemistry laboratory.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding chemical safety

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on chemical handling, storage, disposal, and safety rules into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording safety guidelines

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher summarises the key points of the lesson, reiterating the importance of always prioritising safety in the chemistry laboratory. The teacher encourages students to always be vigilant and responsible when working with chemicals.

Pupils’ Activity: Pupils listen and ask any final questions.

Continuous Assessment/Further Study

Type: Homework/Practice Exercise

Instruction: Answer the following questions in your notebook:

1. List five personal protective equipment (PPE) used in the chemistry laboratory and state the function of each.
2. Imagine you are working in the lab and accidentally spill a corrosive liquid. What are the immediate steps you would take?
3. Research and write down the hazard symbols for “flammable,” “toxic,” and “corrosive” chemicals.
4. Explain why it is dangerous to store acids and bases together.

Lesson Keywords

• Chemicals – Substances with a distinct molecular composition.
• Hazard – A potential source of harm or danger.
• PPE (Personal Protective Equipment) – Equipment worn to minimise exposure to hazards.
• Fume Hood – A ventilated enclosure in a laboratory that protects users from hazardous fumes and vapours.
• Incompatible Chemicals – Chemicals that react dangerously when mixed or stored together.
• Disposal – The act of getting rid of something, especially waste.
• Corrosive – A substance that can cause damage to living tissue or materials through chemical action.
• Flammable – Easily set on fire.

Differentiation

For learners needing support: Provide a simplified checklist of safety rules and handling procedures. Pair them with more confident students during practical demonstrations. Use visual aids like hazard symbol flashcards.

For advanced learners: Challenge them to research specific chemical accidents caused by improper handling or storage and present their findings. Ask them to design a simple chemical storage plan for a small home laboratory, considering different chemical types.

Suggested Lesson Videos

Search on YouTube for: “Chemistry lab safety rules SS1 Nigeria” or “Proper chemical handling storage disposal laboratory”