Understanding Hazardous Substances

What are Hazardous Substances?

Hazardous substances are materials that can cause harm to humans, animals, or the environment. These substances can be found in many forms, such as chemicals, gases, liquids, and solids, and can be used in various industries, including manufacturing, construction, and agriculture.

Examples of hazardous substances include asbestos, lead, mercury, and pesticides. Exposure to these substances can lead to various health problems, including respiratory issues, cancer, and neurological damage.

How To Determine if a Substance is Hazardous

It’s important to know if a substance is hazardous before handling it. Some common signs of dangerous substances include warning labels, Safety Data Sheets (SDS), and pictograms.

• Warning labels are often found on hazardous products and include information such as the type of hazard, precautions for handling the substance, and first aid measures.

• SDS provides more detailed information about a substance’s hazards, including its physical and chemical properties, health effects, and safety precautions.

• Pictograms are symbols used to visually represent the hazards of a substance, such as a flame for a flammable substance or a skull and crossbones for a toxic substance.

If you are unsure if a substance is hazardous, it’s best to err on the side of caution and assume it is until you can confirm otherwise.

How Are They Regulated?

Various government agencies and laws regulate hazardous substances to protect public health and the environment. The Occupational Safety and Health Administration (OSHA) sets standards for workplace exposure to dangerous substances, while the Environmental Protection Agency (EPA) regulates the storage, transportation, and disposal of hazardous materials.

The EPA also enforces the Toxic Substances Control Act (TSCA), which requires companies to report on and test the safety of new chemicals before they are introduced to the market. Meanwhile, the Resource Conservation and Recovery Act (RCRA) regulates hazardous waste generation, transportation, treatment, storage, and disposal.

In addition, the Department of Transportation (DOT) regulates the transportation of hazardous materials, including labeling and packaging requirements. The Food and Drug Administration (FDA) also regulates dangerous substances in food and drugs to ensure they are safe for consumption.

State and local governments may also have regulations for hazardous substances, such as requirements for reporting spills or releases and restrictions on using specific chemicals.

In Australia, Safe Work Australia's workplace exposure limits (WEL) list sets the highest airborne concentration allowed for hundreds of hazardous substances, including dusts, fumes and vapors. From December 1, 2026, it replaces the old workplace exposure standards.

Classifications

The Australian Dangerous Goods (ADG) Code identifies nine categories of hazardous materials. Materials are classified based on their physical and chemical properties, as well as the potential risks they pose.

Class 1: Explosives

Explosives are materials that can cause the sudden and violent release of energy, resulting in an explosion. This class includes various materials, from fireworks and ammunition to industrial explosives used in mining and demolition.

Transportation and storage of explosives require special precautions and regulations to ensure safety, including proper labeling, packaging, and handling procedures.

Class 2: Flammable Gases

Flammable gases can ignite quickly, causing explosions or fires. Examples of combustible gases include propane, butane, and methane. Various industries use these gases, such as welding, heating, and cooking.

Class 3: Flammable Liquids

Liquids that have the potential to ignite in the presence of a source of ignition are categorized as flammable substances. Vehicles, generators, and outdoor power equipment commonly use these power sources.

Class 4: Flammable Solids

Flammable solids are materials that have the potential to ignite on their own or produce combustible gases when exposed to water. The combustion of flammable solids can lead to the emission of hazardous gases.

Class 5: Oxidizing Substances

These substances can release oxygen and support combustion, making them extremely dangerous if improperly handled. Oxidizing substances can be found in various industries, including chemical manufacturing, mining, and transportation. They’re often used as catalysts or chemical reactions to produce other substances.

Class 6: Substances Toxic to People

Class 6 is categorized into two sub-divisions based on the ADG code:

• Toxic substances – Can cause death, serious injury, or harm to human health through ingestion, inhalation, or skin contact

• Infectious substances – May contain pathogens, such as micro-organisms like bacteria, viruses, rickettsiae, parasites, fungi, and other agents like prions that can potentially cause diseases in humans or animals

Class 7: Radioactive Material

These materials emit ionizing radiation, which can cause damage to living cells and tissues. Radioactive materials are used in medical facilities, research labs, and nuclear power plants.

Class 8: Corrosive Substances

They are chemicals that can cause damage to living tissue or other materials upon contact, such as skin, eyes, and metals. Examples of corrosive substances include acids, bases, and certain cleaning products. These substances can cause severe burns, respiratory problems, and other health hazards if not handled properly.

Class 9: Miscellaneous Waste

This category encompasses a wide range of hazardous substances that don’t fit into any other specific category. It includes items such as batteries, pesticides, and asbestos-containing materials. The proper disposal of class 9 hazardous waste is crucial for human and environmental health.

Health Effects of Hazardous Substances

The health impacts of hazardous substances vary based on the specific type and the amount of exposure, including concentration and duration. Exposure to a dangerous substance can occur through inhalation, skin or eye contact, or ingestion. Possible health effects may include:

• poisoning;

• nausea and vomiting;

• headache;

• skin rashes, such as dermatitis;

• chemical burns;

• congenital disabilities;

• disorders of the lung, kidney, or liver; and

• nervous system disorders.

Applying Labels and Safety Data Sheets for Hazardous Substances

Employers are responsible for providing employees with access to Safety Data Sheets for all hazardous substances used in the workplace and maintaining a central register of such chemicals.

Warning labels on hazardous substances must comply with the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) or other methods outlined by the Occupational Safety & Health Administration (OSHA). It would also be beneficial to use signs and symbols compliant with ISO 7000.

Recommended guidelines for warning labels on hazardous substances include:

• Hazard pictograms

• Signal words (such as danger and warning)

• Hazard statements (such as fatal if swallowed)

• Precautionary statements (such as wearing protective gloves)

To classify and communicate chemical hazards internationally, the Global Harmonized System (GHS) uses pictograms, terminology, and data on chemical labels.

The Safety Data Sheet also provides essential details on safe product handling, which include:

• Impacts on health

• Safety precautions

• Guidelines for safe storage

• First aid instructions for emergencies

• Contact numbers for additional information

Reducing Exposure to these Substances

Recommendations for decreasing contact with dangerous materials at work consist of the following:

• Use non-hazardous materials whenever possible.

• Substitute less hazardous alternatives for hazardous substances (for example, use detergent instead of chlorinated solvent for cleaning).

• Separate hazardous substances from non-hazardous substances.

• Purge or ventilate storage areas separately from other work areas.

• Train employees thoroughly in handling and safety procedures.

• Make sure Personal Protection Equipment (PPE), such as gloves, goggles, and respirators, is available.

• Track the level of hazardous substances in the air and environment at the workplace with adequate monitoring equipment.

• Consult regularly with employees to maintain and improve existing safety practices.

Keeping Written Records for these Substances

OSHA requires recording hazardous substances at work, including:

• Risk assessment details

• Air and environment test results, if applicable

• Employee health monitoring details, if applicable

• Detailed records of all employees exposed to scheduled carcinogens