Unit 01 Section 03 Lesson 04


Laboratory Safety Skill

Safety Issues

This lesson is to be considered one of the most important lessons you complete!
Your safety and the safety of those around you depends on your understanding of the potential dangers associated with completing lab investigations .

Throughout the years, many scientists have learned lab safety lessons the hard way. Their experiences have given rise to procedures designed to promote the safety of those who have followed them into the lab. It is your responsibility and that of the professionals at your school to ensure that proper safety procedures are followed when you complete lab activities. 

As a student of science, it is essential that you have a clear understanding of all of the activities that you will be carrying out, including potential dangers. It is also important that you know what to do in case of an accident. Click the links below to print off Lab#1 and the safety contract.

Hazardous Household Product Symbols

As you complete the activities for this lesson you should look for products around your home and find labels with safety symbols similar to the one shown below. These are known as HHPS which stands for Hazardous Household Product Symbols. There are four HHPS which are used as warnings to home consumers. The Bleach container below shows an example of one of these four symbols which is the symbol for corrosive materials:

Flammable Liquids........

Similar systems exist for materials in the transportation industry. For example, you may have seen special placards on trucks and boats that carry flammable liquids.


The four HHPS symbols are for Corrosive, Flammable, Explosive and Poisonous materials.

 Click here to view HHPS Symbols. Also, see Nelson Science 10 text, Table 2, page 253 as well as page 72.

What does WHMIS stand for? ........

It stands for Workplace Hazardous Materials Information System.

Chemicals in laboratories are labeled using  this system which is WHMIS. This method of labeling is one of many information systems designed to warn people of the hazards associated with chemical substances in the workplace.

WHMIS uses a set of symbols to indicate the potential hazards posed by chemicals used in the workplace and in educational institutions. You have to become familiar with the symbols and their meanings even though you may not encounter all the classes of hazardous substances listed below as you complete activities at your school.

 These symbols are also found in your Nelson Science 10  text on page 72 and page 252.

Compressed Gases
  • danger of an explosion because gas is under pressure
  • examples: natural gas, propane

Class A Symbol


Flammable and Combustible Materials
  • danger of fire or explosion when exposed to heat, sparks, flame or friction or upon contact with water
  • examples: white phosphorus, butane, acetone (cleaner/solvent)

Class C


Oxidizing Materials
  • danger of fire or explosion in presence of flammable or combustible materials; may cause burns on contact with skin
  • examples: peroxides, chlorates, acids containing oxygen

Class D- Division2


Materials Causing Immediate and Serious Toxic Effects
  • danger of fatality if inhaled, swallowed, or absorbed through skin; may burn skin or eyes
  • examples: methanol (gas line antifreeze), ethylene glycol (engine coolant), cyanides, sulfuric acid (battery acid)

Class B


Materials Causing Other Toxic Effects
  • danger of poisoning; prolonged exposure may lead to death or permanent disability; danger of irritation; may cause cancer, birth defects or sterility
  • examples: asbestos (in some insulating tiles and floor tiles), toluene (paint stripper), benzene, barium ions, lead (e.g. car batteries)

Class E


Biohazardous Infectious Materials
  • danger of contraction of a disease
  • examples: medical waste, blood, bacterial specimens

Class D-Division 1


Corrosive Materials
  • danger of severe skin or eye irritation on contact; causes severe tissue damage; may be harmful if inhaled; may react with metals and release harmful gases
  • examples: sulfuric acid, hydrochloric acid (brick layer's acid), sodium hydroxide (lye, fiber separator in paper mills)

Class D - Division 3


Dangerously Reactive Materials
  • danger of release of toxic or flammable gas upon contact with water; may explode as a result of disturbance, friction, increase in temperature; may react rapidly release large amounts of heat
  • examples: sodium metal, trinitrotoluene (TNT), certain cyanides (gold refining)

Class F

Materials Safety Data Sheet.....

In addition to the WHMIS symbols, each package of chemicals purchased in a school laboratory comes with a MSDS (Materials Safety Data Sheet) which lists nine categories or sections of information. The images below show a typical MSDS sheet (which for this lesson has been cut into two parts for easy viewing).

Look over this MSDS sheet (shown in two parts) and identify the nine sections of information.

[Left half of MSDS sheet shown below]

[ Right half of MSDS sheet shown below]




2004 CDLI