What Are Hazardous Chemicals?

What Are Hazardous Chemicals

Hazardous Chemicals

Under the WHS Regulations, a hazardous chemical is any substance, mixture or article that satisfies the criteria of one or more Globally Harmonised System of Classification and Labelling of Chemicals (GHS) hazard classes, including a classification in Schedule 6 of the WHS Regulations.

However, some hazard classes and categories of the GHS are excluded by the WHS Regulations. See Appendix A for the definition of ‘hazardous chemical’ and other terms used in this Code.

Most substances and mixtures that are dangerous goods under the ADG Code are hazardous chemicals, except those that have only radioactive hazards (class 7 dangerous goods), infectious substances (division 6.2) and most class 9 (miscellaneous) dangerous goods.

A comparison of dangerous goods classifications under the ADG code with those under the GHS is provided in Appendix B.

In relation to chemicals, a hazard is a set of inherent properties of the substance, mixture, article or process that may cause adverse effects to organisms or the environment.

There are two broad types of hazards associated with hazardous chemicals which may present an immediate or long-term injury or illness to people. These are:

  • Health hazards – These are properties of a chemical that have the potential to cause adverse health effects. Exposure usually occurs through inhalation, skin contact or ingestion. Adverse health effects can be acute (short-term) or chronic (long-term). Typical acute health effects include headaches, nausea or vomiting and skin corrosion, while chronic health effects include asthma, dermatitis, nerve damage or cancer.
  • Physicochemical hazards – These are physical or chemical properties of the substance, mixture or article that pose risks to workers other than health risks, as they do not occur as a consequence of the biological interaction of the chemical with people. They arise through inappropriate handling or use and can often result in injury to people and/or damage to property as a result of the intrinsic physical hazard. Examples of physicochemical hazards include flammable, corrosive, explosive, chemically reactive and oxidising chemicals.

Many chemicals have both health and physicochemical hazards.

Health Effects Of Ethylene Oxide Chemical

Who has health and safety duties in relation to hazardous chemicals?

Under the WHS Act, a person conducting a business or undertaking has the primary duty to ensure, so far as is reasonably practicable, that the health and safety of workers and other persons are not put at risk from work carried out as part of the conduct of the business or undertaking. This includes ensuring the safe use, handling and storage of substances.

The WHS Regulations include specific duties for a person conducting a business or undertaking to manage the risks to health and safety associated with using, handling, generating and storing hazardous chemicals at a workplace. The duties include:

  • Correct Labelling Of Containers And Pipework, Using Warning Placards And Outer Warning Placards And Displaying Of Safety Signs
  • Maintaining A Register And Manifest (Where Relevant) Of Hazardous Chemicals And Providing Notification To The Regulator Of Manifest Quantities If Required
  • Identifying Risk Of Physical Or Chemical Reaction Of Hazardous Chemicals And Ensuring The Stability Of Hazardous Chemicals
  • Ensuring That Exposure Standards Are Not Exceeded
  • Provision Of Health Monitoring To Workers
  • Provision Of Information, Training, Instruction And Supervision To Workers
  • Provision Of Spill Containment System For Hazardous Chemicals If Necessary
  • Obtaining The Current Safety Data Sheet (Sds) From The Manufacturer, Importer Or Supplier Of The Chemical
  • Controlling Ignition Sources And Accumulation Of Flammable And Combustible Substances
  • Provision And Availability Of Fire Protection, Fire Fighting Equipment And Emergency And Safety Equipment
  • Preparing An Emergency Plan If The Quantity Of A Class Of Hazardous Chemical At A Workplace
  • Exceeds The Manifest Quantity For That Hazardous Chemical
  • Stability And Support Of Containers For Bulk Hazardous Chemicals Including Pipework And Attachments
  • Decommissioning Of Underground Storage And Handling Systems
  • Notifying The Regulator As Soon As Practicable Of Abandoned Tanks In Certain Circumstances

The WHS Regulations contain prohibitions or restrictions on certain hazardous chemicals (e.g. certain carcinogens) except in specified circumstances and a restriction on the age of a person who can supply hazardous chemicals.

There are also duties relating to the building, operation and management of pipelines used for the transfer of hazardous chemicals.

Designers, manufacturers, importers and suppliers of substances must also ensure, so far as is reasonably practicable, that the substance they design, manufacture, import or supply is without risks to health and safety. Under the WHS Regulations, manufacturers and importers must correctly classify hazardous chemicals.

The WHS Regulations also impose duties on importers, manufacturers and suppliers relating to the preparation of safety data sheets (SDS), the disclosure of ingredients, packing, labelling and supply of hazardous chemicals.

Officers, such as company directors, have a duty to exercise due diligence to ensure that the business or undertaking complies with the WHS Act and Regulations. This includes taking reasonable steps to ensure that the business or undertaking has and uses appropriate resources and processes to eliminate or minimise risks that arise from hazardous chemicals at the workplace.

Workers have a duty to take reasonable care for their own health and safety and must not adversely affect the health and safety of other persons. Workers must comply with any reasonable instruction and cooperate with any reasonable policy or procedure relating to the use, handling and storage of hazardous chemicals at the workplace.

What is required to manage the risks associated with hazardous chemicals?

A person conducting a business or undertaking must manage risks associated with using, handling, generating or storing of hazardous chemicals at a workplace. In order to manage risk under the WHS Regulations, a duty holder must:

a) identify reasonably foreseeable hazards that could give rise to the risk

b) eliminate the risk so far as is reasonably practicable

c) if it is not reasonably practicable to eliminate the risk – minimise the risk so far as is reasonably practicable by implementing control measures in accordance with the hierarchy of risk control

d) maintain the implemented control measure so that it remains effective

e) review, and if necessary revise all risk control measures so as to maintain, so far as is reasonably practicable, a work environment that is without risks to health and safety

This Code provides guidance on how to manage the risks associated with hazardous chemicals in the workplace by following a systematic process that involves:

  • identifying hazards
  • if necessary, assessing the risks associated with these hazards
  • eliminating or minimising the risks of implementing and maintaining control measures
  • reviewing control measures to ensure they are effective.

When managing the risks, regard must be had to the following factors:

The hazardous properties of the hazardous chemical

Any potentially hazardous reaction (chemical or physical) between the hazardous chemical and another substance or mixture, including a substance that may be generated by the reaction

The nature of the work to be carried out with the hazardous chemical

  • any structure, plant or system of work that: is used in the use, handling, generation or storage of the hazardous chemical
  • could interact with the hazardous chemical at the workplace.

Guidance on the general risk management process is available in the Code of Practice: How to Manage Work Health and Safety Risks.


The WHS Act requires that you consult, so far as is reasonably practicable, with workers who carry out work for you who are (or are likely to be) directly affected by a work health and safety matter.

If the workers are represented by a health and safety representative, the consultation must involve that representative.

Health and safety representatives must have access to relevant information on matters that can affect the health and safety of workers, for example, hazardous chemicals register and data from monitoring airborne contaminants. Consultation with workers and their health and safety representatives is a critical step of managing work health and safety risks. Consulting with and involving workers in the risk management process can assist in ensuring that safety instructions and safe work practices are complied with.


The WHS Act requires that you consult, co-operate and co-ordinate activities with all other persons who have a work health or safety duty in relation to the same matter, so far as is reasonably practicable.

Sometimes you may share responsibility for a health and safety matter with other business operators who are involved in the same activities or who share the same workplace. In these situations, you should exchange information to find out who is doing what and work together in a co-operative and co-ordinated way so that all risks are eliminated or minimised as far as reasonably practicable.

For example, if you engage a contractor to carry out cleaning at your workplace that involves the use of chemicals, you should find out what is being used, whether there are any hazards associated with the chemicals and how the risks will be controlled.

This might, for example, include jointly preparing a risk assessment for the chemicals being used, how they will be handled and measures that should be taken to eliminate or minimise exposure. After the risk assessment has been prepared, it is important for all duty holders to co-operate and co-ordinate activities with each other to implement the control measures.

Further guidance on consultation is available in the Code of Practice: Work Health and Safety Consultation, Co-operation and Co-ordination.

Chemical Safety Quiz

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