Safe Practices in a High School Science Lab
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Transcript of Safe Practices in a High School Science Lab
Safe Practices in a High School Science Lab
3 Recent Classroom Accidents
1.Students injured in Science class blast
• demonstration of how different chemicals burn
• nearby bunsen burner ignited 1L beaker of methanol in teacher’s hand
• flames scattered onto students in front row
3 Recent Classroom Accidents
2.Science experiment burns student
• demonstration of whoosh bottle experiment
•more alcohol added after first demo
•flame shoots out of jug burning student about 2 metres
away from demo
3 Recent Classroom Accidents
3.Teacher and students suffer lacerations
in Science lab explosion
• demonstration of exothermic reaction –
potassium chlorate, manganese dioxide, sugar and glycerin
• teacher wearing safety glasses; students moved back
Know Your lab
ExitsLab door(s)Stop button (power)Glass disposal box (broom/dustpan)
Eye wash/showerFume hoodFire extinguisher(s)/ blanket(s)First-Aid kits
Prevent Problems
Traffic flow of students what can you do to minimize traffic and congestion?
Where to ‘stand & circulate’ during labs what can/will go wrong during labs always have a clear sightline of every student
How will materials/lab equipment be distributed & collected? have a student in charge from each station to retrieve/return the materials, also have a student who is on ‘clean up patrol’ where they need to wipe counters, inspect area and report back to you on the condition of their lab station.
Allow for startup and cleanup time. Including waste collection (and in some cases treatment and disposal)
Model safe behaviour (wear your goggles, tie your hair back etc…)
Only bring enough chemicals/equipment for what you need (easier to track its return and count).
Save time for clean-up and wrapping up the lesson.
Fire Safety Knowledge and Skills
Knowledge for Handling Flammable and
Combustible Substances
1. Type of Flammable and Combustible
Materials
2. Quantity of Flammable and Combustible
Materials
3. Concentration of Flammable and Combustible Materials
Fire Safety Knowledge and Skills
Knowledge and Skills for Preparation of Activities
4. Room Readiness
― Safety equipment
5. Storage and Disposal
6. Classroom Management
― Assessment of student skill level and
readiness
7. Choice of Heat Source
― Suitable flame source
Knowledge and Skills for Emergencies
8. Dealing with Unintended Flame
How to choose safe chemicals?
1. Consult your Board chemical list (if available)
2.Consult the HMIS rating on vendor MSDS
e.g., Boreal Northwest
www.boreal.com
Video 1 - H2, O2, and CO2
Video 1 - Testing Gases – H2, O2, and CO2
Video 1
Video 1 – Testing Gases H2, O2, and CO2
Discussion Questions
1. What categories (classes) of chemicals are used in this activity?
2. What specialised equipment is used?
3. What safety precautions were taken during this activity?
4. What classroom management concerns were addressed in the video?
Chemical Segregation in the Storage Room
Chemical Storage Groups (*adapted from SOS page 37)
Group Storage Provision Store Away From Flammable and Combustible liquids (e.g., alcohols)
Fire-resistant ‘Flammables Cabinet’
Oxidizers and toxics
Flammable and Combustible Water-reactive Solids (e.g., alkali metals)
Separate cupboard or cabinet
Oxidizers, corrosive liquids, and flammable liquids
Highly Toxic Chemicals (e.g., Mercury)
Usually banned by most boards
Flammable liquids
Corrosive Liquids, acids (e.g., conc. HCl)
Vented ‘Acid Cabinet’; HNO3 should be isolated
Non-acid corrosive liquids, water-reactive solids and toxics
Chemical Segregation in the Storage Room
Chemical Storage Groups (*adapted from SOS page 37)
Group Storage Provision Store Away From
Corrosive Liquids, bases (e.g., NaOH solution)
Not in glass containers Acids, water-reactive solids and toxics
Corrosive Solids (e.g., NaoH)
With general chemicals
Oxidizing Agents (e.g., peroxides, chlorates)
In plastic trays Flammable liquids/solids, water-reactive solids, organics, corrosive liquids
General Chemicals Inorganics/organics
Video 2 – Reactivity of Metals Li, Na, and K
Video 2 - Reactivity of Metals – Li, Na, and K
Video 2
Video 2 – Reactivity of Metals
Discussion Questions
1. What categories (classes) of chemicals are used in this activity?
2. What specialised equipment is used?
3. What safety precautions were taken during this activity?
4. What classroom management concerns were addressed in the video?
Video 5 – Ester Synthesis
Video 5
Summary - Application of Knowledge
Video 5 – Ester Synthesis
1. What safety precautions were taken during this activity?
Safe ON Science
Written by the STAO/APSO Safety
Committee
Available at the STAO/APSO online
store
www.stao.org