Toxic gases are necessary for a range of applications including energy production, wastewater treatment, petrochemical processing and manufacturing. However, the chemical and physical properties of these gases must be managed to ensure a safe working environment. In this post, we'll be looking at toxic gas in the workplace. We’ll be explaining why these common substances — such as sulphur dioxide and carbon monoxide — need to be properly controlled to ensure safety.
Is Toxic Gas Classed as a Dangerous Good?
Handling hazardous chemicals and dangerous goods is just part of the normal working day for countless businesses and sectors. When dealing with gases, it's essential that you are aware of the properties, hazards and controls necessary for that chemical.
Gases in the workplace post both physical and chemical risks.
Toxic gases in the workplace are just part of the compressed gases classified as 'dangerous goods'. The divisions of Class 2 dangerous goods include:
Division 2.1 Flammable Gas
These substances must be isolated from sources of ignition to ensure there is no fire or explosion risk. Class 2.1 Flammable Gases can also have toxic properties, which can pose harm to the staff who are working with them.
Division 2.2 Non-Flammable, Non-Toxic Gas
Not to be confused with a non-hazardous chemical, Division 2.2 gases can still create hazards. Some Class 2.2 Gases can pose an asphyxiation risk, as they displace oxygen in the air. Some gases can be reactive and oxidising, which causes or contributes to the combustion of other material.
Division 2.3 Toxic Gas
Toxic gases pose a threat to human health due to the hazardous properties of the gas. Many toxic gases are also corrosive, which can create acute or fatal injuries if the gases are inhaled or make contact with the skin.
REMEMBER: All compressed gas in cylinders pose a physical hazard, due to the size and weight of the cylinder - and the risks associated with a rapid release of gas due to mishandling, accidents during industrial processes, equipment failure, inappropriate storage or the overheating of cylinders.
Identifying Toxic Gases
To determine if your gas cylinders contain a Class 2.3 Toxic Gas, you must refer to the individual safety data sheet (SDS) for each product onsite.
Correctly identifying your toxic gases is the first step in understanding and controlling their hazards.
Some particular sections of your SDS to pay attention to when identifying the dangerous goods class of your chemical includes Section 1: identification and Section 14: transport information.
REMEMBER: Your safety data sheet contains all the chemical and physical hazards of your gas, as well as the first aid measures, safe storage and handling practices, emergency information and more.
Division 2.3 Toxic Gas Examples
Some types of toxic gas often used in the workplace include:
- Anhydrous ammonia
- Carbon dioxide
- Chlorine
- Hydrogen sulphide
- Nitrogen dioxide
- Sulphur dioxide
Toxic Gas Exposure
As a poisonous gas, Class 2.3 substances can harm humans, animals and wildlife if they're exposed to the chemical. Therefore, controlling these gases in the workplace is important for site safety, as well as the health of the surrounding community and natural environment.
There have been many instances where an uncontrolled release of toxic gas has caused nearby workers and other personnel to succumb to toxic exposure. When released in small amounts, this gas can cause harm to your workforce - however, if you're keeping bulk supplies of toxic gas in a workplace, the effects of the accidental release can be devastating for nearby communities.
Health Effects
If staff are exposed to toxic gas inhalation, it can create a range of health issues. Acute exposure can also result in fatalities.
Toxic gases can affect people through these exposure routes:
- Inhalation - breathing in a gas that has been accidentally released from the cylinder, due to a broken valve, dropping of the cylinder or other means. Inhaled gases can be lethal.
- Contact with skin or eyes - if gases come into contact with the eyes or skin, the toxic substances can penetrate the tissue and make their way into the blood stream.
Some serious health problems related to acute toxic gas exposure include:
- Airflow obstruction
- Acute upper airway inflammation
- Bronchiectasis
- Delayed pulmonary edema
According to the Australian Institute of Health and Welfare (AIHW), gases and vapours contributed to 17% of the accidental poisoning hospitalisations from 2020-2021 for non-pharmaceutical substances. This figure compares with 5% of accidental poisoning related to pesticides and 10% related to alcohol.
While not all of these hospitalisations are due to Class 2.3 gases (as other types of gases — such as flammable gases — may also have toxic properties), toxic gases pose a real risk to workers who are tasked with handling, transporting and storing the cylinders.
Controlling Division 2.3 Gas Dangers
When considering both the chemical properties and physical properties of toxic gases, you can see the importance of ensuring you have the correct hazard control methods in place.
Some key controls for compressed toxic gas cylinders include:
- Keep compliant gas cages and gas stores to minimise chemical and physical risks
- Prevent theft, misuse or vandalism by locking the gas cage and implementing additional security measures, such as fencing that’s secured against unauthorised access
- Understand the chemical incompatibilities of your gases and implementing dangerous goods segregation to control the risk
- Keep all Class 2.3 gases away from other gas cylinders
- Separate gases from protected and public places
- Ensure all staff use and maintain the PPE, as required in the safety data sheet
- If toxic gas cylinders are not in use, they should be fitted with a gas-tight outlet cap or plug.
- Use a gas trolley or lifting device that offers cylinder restraints when moving cylinders
- Keep cylinders upright
- Regularly inspect cylinder valves for damage
- Store toxic gases outside where possible to reduce risk of toxic gas inhalation exposure and poisoning
- Create a well-ventilated space for storage and handling of toxic gases (see the Australian Standard 4332 to learn more about compliant ventilation systems for gases)
- Monitor airborne contaminants to ensure that levels comply with the workplace exposure standards
- Avoid environments with extreme heat or sources of heat (such as welding equipment) which may overheat the cylinder and cause it to rapidly release
- Develop regular inspections and safety audits to make sure gas handling and storage procedures are being followed
- Maintain the correct dangerous goods and hazard signage for storage areas
Like to learn more about chemical segregation?
Avoiding Toxic Gas Inhalation Injury
One of the most important and simple ways that you can reduce the likelihood of toxic gas inhalation is by making sure your cylinders are secured, upright and safe. This can be achieved with the installation and maintenance of a compliant gas cage.
To learn more about toxic gas safety, you can access our helpful eBook. Gas Cylinder Storage: Compliance and Safety Requirements references the requirements of the Australian Standard AS 4332 to explain where to store your cylinders, how to segregate incompatible gases and how to handle the chemicals safely. Get your copy now to find out more.
