Laboratory Safety: Rules and Procedures

• General laboratory rules ensure safety and prevent accidents
• There is a reason for each rule
• Students should be aware of each to maintain safe lab environment

General Laboratory Rules

• No eating or drinking in the lab to prevent consuming toxic chemicals
• Students can only enter with teacher's permission
• Only necessary equipment allowed to avoid tripping hazards
• No running or horseplay permitted in the lab
• Chemicals, apparatus, plants, charts, or displays can only be touched with permission
• Unauthorized experiments should not be attempted
• Keep workstations tidy to minimize risk of spills
• Students cannot enter the storeroom due to dangerous chemicals
• Accidents must be reported immediately for emergency response and unsafe situations to be handled.

Performing Practical Experiments:

• Always wear safety goggles
• Handle apparatus as directed
• Report any cuts or eye injuries immediately
• Wash hands after every experiment to remove unseen chemicals.
• Never taste or smell chemicals unless instructed
• Test odors carefully
• Point test tubes away from yourself and others when heating substances.
• Handle sharp apparatus carefully
• Only open gas and water taps when told to
• Ensure apparatus is cleaned, packed away, and gas/water taps are closed after use

Chemical Safety:

• Avoid breathing chemicals in
• Avoid skin contact
• Do not taste chemicals
• Keep Bunsen burners away from flammable materials
• Understand safety symbols
• Safety glasses, gloves, and coats are necessary when working with chemicals
• Wash hands after every practical
• Tell your teacher if spillage occurs
• Only use the correct amount of chemicals needed
• All chemical labels and instructions must be read carefully
• Do not run while holding chemicals
• Do not mix spoons and stirrers between chemicals

Allergies and Immediate Notification:

• Immediately inform your teacher about any chemical allergies e.g. sulphur compounds or latex.

Symbols Meanings in Safety

• Symbols are better than words for conveying info re: poison, irritant, flammable etc., because people of all languages can understand standardized symbols.
• International Chemical Safety Cards (ICSC) or Material Safety Data Sheets (MSDS) accompany chemicals. The focus is on concisely promoting the safe usage of chemicals within laboratories.
• The rating explanation guide: health, flammability, and instability

Safety Symbols

• Danger: General warning, broken glass, spilled chemical
• Harmful or Irritant: can harm your health and irritant means that the chemical may give you a rash if you get it on you or make you choke if you breathe it in.
• Corrosive: causes damage to the skin
• Highly flammable: will catch fire easily
• Risk of electric shock: can cause dangerous electric shock if used incorrectly
• Toxic: means that a chemical is poisonous
• Biohazard: some type of living organism is in an area that will make you ill.
• Eye protection must be worn: wear safety glasses or goggles when working in certain area
• Wash your hands: wash your hands after you have completed an experiment

Health Hazard Levels:

• 4: Deadly
• 3: Extreme Danger
• 2: Hazardous
• 1: Slightly Hazardous
• 0: Normal Material

Fire Hazard Flash Points:

• 4: Below 73°F
• 3: Below 100°F
• 2: Below 200°F
• 1: Above 200°F
• 0: Will Not Burn

Instability Levels:

• 4: May Detonate
• 3: Shock + Heat may Detonate
• 2: Violent Chemical Change
• 1: Unstable if Heated
• 0: Stable

Specific Hazard Codes:

• OX: Oxidizer
• ACID: Acid
• ALK: Alkaline
• COR: Corrosive
• W with a line through it: Use No Water
• Radioactive symbol

Helium

• Fire Hazard = 0 (Will not burn)
• Instability = 0 (Stable)
• Specific Hazard = (None); Displaces O2
• Health Hazard = 3 (Extreme danger); Suffocation
• Contact with Compressed Gas = Frostbite
• Description = Colorless, odorless gas, stored as compressed gas

Ethanol

• Fire Hazard = 3 (Highly Flammable)
• Instability = 0 (Stable)
• Specific Hazard = Combustible.
• Health Hazard = 2 (Hazardous).
• Causes severe eye/skin irritation
• Repeated exposure damages liver, kidney and central nervous system
• (Discuss Alcoholism & dangers)

Sulphuric acid

• Fire Hazard = 0 (Will not burn)
• Instability = 2 (Violent chemical change)
• Specific Hazard = (Use no water)
• Health Hazard = 3 (Extreme danger)
• Corrosive; Burns.
• Chronic: tooth erosion, gastric-intestinal (GI) disturbances and dermatitis

Diagrams in Science

• Used to show the apparatus

Why drawings diagrams is useful

• Standardisation
• Scientists draw the same diagrams
• Diagrams are faster to draw

Different types of Apparatus

• Test tube: for storing/mixing solids and liquids
• Boiling tube/large test tube: for heating solids and liquids
• Beaker: Determining approximate volume of liquids or storing liquids or solids
• Conical flask: for storing/mixing liquids
• Measuring cylinder: Determining accurate volume of liquids
• Tripod: for heating a beaker, flask, or crucible over a Bunsen burner
• Gauze: for supporting a beaker or flask and spreading the heat from the flame
• Bunsen burner: Used as a heat source
• Evaporating basin/dish: for evaporating the water from a solution
• Filter funnel (with paper): for pouring liquids without spilling, and will hold a filter paper in place
• Rubber stopper/bung: To close a test tube
• Rubber stopper/bung with a hole: The hole is so that a tube or thermometer can be put into the liquid without any gases escaping
• Retort stand: Used to support other apparatus and glassware
• Eureka/displacement can: Used to measure the volume of an irregular-shaped object
• Spatula: Used to transfer solid chemicals
• Crucible tongs: Used to handle hot crucibles
• Beaker tongs: Used to handle hot beakers
• Burette: Used to accurately measure the volume of a liquid.
• Test tube rack: Used to hot test tubes
• Pipette: Used to measure a single volume of a liquid
• Micro-pipette/dropper: Used to measure a single volume of a liquid
• Thermometer: Generally drawn on diagram is to measure the temperature of a substance
• Electronic mass balance: Generally not drawn on diagram is used to measure the mass of an object.
• Triple beam balance: Generally not drawn on diagram; Accurate measure of the mass of an object
• Spring balance: Generally not drawn on diagram used to measure the weight of an object
• Filtration: Used to separate an insoluble solid from a solid-liquid mixture (suspension)
• Evaporation: Used to separate a soluble liquid from a solid-liquid mixture (solution)

Bunsen Burner

• Produces a single open gas flame, used for heating, sterilization, and combustion in the laboratory.

Safety with a Bunsen burner;

• Always wear safety glasses
• Always check water bath
• Turn off Bunsen burner when not in use
• Turn off the gas & notify your teacher if a malfunction occurs

Steps to Light a Bunsen Burner

• Place on heat mat or tile
• Check the hose for breaks
• Connect the hose to the gas tap but do not turn on the gas yet
• Close the air-hole in the collar of the Bunsen burner
• Light a match and hold it above the top of the chimney of the Bunsen burner
• Turn on the gas tap, Bunsen burner should light up (yellow flame)
• Open the air hole slowly to adjust the type of flame needed for your experiment -Turn down the gas supply to adjust the size of the flame -Turn off the gas tap if the Bunsen burner goes out

Important Bunsen Burner Information

• When not in use, the Bunsen burner should always be turned off, or airhole should be closed to ensure the orange safety flame is visible
• Hair must be tied back, long hair tied up
• Lab coat that have closed-toed shoes must be worn
• Eye-wash/rinse station must be used if eyes burn
• Always work in the lab with another person present

Flame Types:

• Safety Flame
  • Airhole almost closed
  • Very little oxygen mixing with gas
  • Quiet
  • Orange
  • Low amount of energy, flame 300 degrees Celsius
  • Not used for heating
• Medium Flame
  • Airhole half open
  • Some oxygen mixes with gas
  • Slight noise
  • Orange and Blue
  • Medium amount of energy, Flame approx. 500 degrees Celsius
  • Used for heating liquids
• Roaring Flame
  • Airhole fully open
  • A lot of oxygen mixing with gas
  • Roaring/ Very noisy
  • Blue
  • High amount of energy. Very hot flame, approx. 700 degrees Celsius
  • Used for heating/melting solids

Bunsen burner parts:

• Collar
• Base
• Gas valve
• Barrel or chimney
• Flame (inner cone)
• Rubber tubing
• Flame (Outer cone)
• Air hole
• Heat proof surface