Volatile Organic Compounds
Summary
Volatile organic compounds (VOCs) are a group of organic chemicals that readily evaporate into the air at ambient temperatures. VOCs are commonly associated with fuel, solvents, industrial chemicals and waste products and are frequently encountered in contaminated land and groundwater investigations.
Due to their volatility and mobility, VOCs can migrate through soil, groundwater and air, creating potential risks to human health and indoor environments.
Definition
Volatile organic compounds are carbon-based chemicals that have a high vapour pressure, allowing them to easily transition from liquid or solid form into vapour. Common VOCs include petroleum hydrocarbons, chlorinated solvents and aromatic compounds such as benzene.
In environmental assessments, VOCs are typically analysed in soil, groundwater, soil vapour or indoor air to assess contamination and exposure pathways.
Why VOCs Matter
From a health perspective, exposure to VOCs can occur through inhalation of vapours, direct contact with contaminated media or ingestion of contaminated water. Some VOCs are toxic, carcinogenic or associated with acute health effects at elevated concentrations.
From a contaminated land perspective, VOCs are particularly important because they can migrate away from the source area and enter buildings through vapour intrusion pathways. This can create risks even where soil contamination appears limited.
VOCs also present regulatory and planning challenges. Their presence can trigger requirements for further investigation, vapour risk assessment, remediation or long-term management. Failure to identify VOCs early can result in unexpected constraints during development or occupation.
Common Sources of VOC Contamination
VOCs are commonly associated with:
Service stations and fuel storage facilities
Industrial and manufacturing activities
Dry cleaning and solvent use
Chemical storage and waste disposal
Landfills and waste-filled land
Understanding site history is critical for identifying potential VOC risks.
When VOCs Are Typically Assessed
Assessment of VOCs is commonly required where:
A Preliminary or Detailed Site Investigation is undertaken
Petroleum or solvent contamination is suspected
Groundwater contamination is identified
Development is proposed on contaminated land
Vapour intrusion risk needs to be assessed
Environmental due diligence identifies VOC-related risk
Assessment may involve soil, groundwater, vapour or indoor air sampling.
Legislative and Regulatory Context
VOCs are assessed under contaminated land and environmental protection frameworks.
In New South Wales, VOCs are commonly assessed in accordance with EPA guidance and industry criteria as part of contaminated land investigations, vapour assessments and development approvals. Similar regulatory expectations apply across Australia.
Regulators expect VOC assessments to consider both direct exposure and vapour migration pathways.
How We Can Help
Confluence Environmental assesses VOCs as part of contaminated land, groundwater and vapour risk investigations.
Our services typically include:
Identification of potential VOC sources and pathways
Soil, groundwater and vapour sampling
Interpretation of results against applicable criteria
Assessment of vapour intrusion risk
Advice on remediation or management options
Reporting to support planning and regulatory review
We focus on providing clear, defensible assessments aligned with site-specific risk.
Related Terms and Concepts
Contaminated Land
Underground Petroleum Storage System
Petroleum Hydrocarbons
Groundwater Sampling
Soil Vapour Assessment
Environmental Site Assessment
Site Remediation