Odour is a mixture of gases in the air that we can smell. Odour is also a kind of pollution, and there are laws about managing it.

What causes odour

Your business can produce odour across many different activities, for example: 

• storing and handling raw materials 
• during processing  
• in the waste, products or by-products from your business.  

Examples of businesses that need to manage odour include: 

• landfills 
• coffee roasters 
• bakeries 
• organic waste or compost facilities 
• animal processing facilities. For example, rendering facilities and abattoirs 
• breweries 
• sewage and wastewater treatment facilities 
• spray painters and powder coaters 
• plastic moulders. 

Why eliminating or reducing odour is important

When not appropriately managed, odour can impact the environment and community in many ways. This includes: 

• local amenity and enjoyment 
• human health and wellbeing
• ecosystems and biodiversity. 

As a business, eliminating or reducing the risks of harm from odour in a structured way will help you: 

• meet community expectations 
• prevent harm to human health and the environment 
• comply with your environmental duties and obligations. 

Not eliminating or reducing your environmental risk means you could face cleanup costs, lost work time, legal fees, fines and criminal charges. 

Odour and your duties

Businesses must make sure that any odour from their activities or premises doesn’t impact the local community. This includes being responsible for contractors or tradespeople they may hire. 

There are laws about odour that cover air pollution and air quality. The primary aim of these laws is to create an atmosphere that is free from offensive odours.

Assessing odour

Offensive odour interferes with people’s normal enjoyment or use of the environment.  It can cause people to feel revolted, disgusted, upset, or annoyed. Odour is subjective and varies in its perception from person to person.

To help you assess the risk of offensive odour, EPA has published guidance for assessing odour (publication 1883). 

Who is this guidance for?

• The government
• The planning sector
• Practitioners and specialists.

These stakeholders need to understand offensive odours and their association with development proposals, investigations or studies where an odour assessment is required.  'Risk assessment' relates to whether the risk of harm can be understood through the assessment framework. 

Why is this useful?

Our Guidance for assessing odour provides information on how to assess the risk posed by odour emission sources, and to understand the receiving environment where effects might occur. It focuses on the assessment of odour under the provisions of the Act, including the General Environmental Duty (GED). The GED requires all Victorians to take reasonable precautions to avoid hazards causing harm.

This publication provides guidance on:

• Odour assessment framework
• What to include in assessment reports
• How to make odour assessment decisions in the presence of uncertainty
• Industrial odors categories, odour descriptions, and odour assessment templates. 

How does odour assessment work?

The guidance describes 3 levels of odour assessment. Progression through each level of assessment depends on the scale or complexity of each scenario. These can be performed in sequence. That is, if lower levels of assessment show that the activity is low risk for odour, there is no need to proceed to the higher levels of assessment.

Level 1 assessment

This is a “gateway assessment” and includes tests for:

• Cumulative sources consideration.
• Duration of emissions.
• Wind direction.
• Minor odour emission sources.

Level 2 assessment

This consists of two tools. These are the cumulative effects test and the source-pathway-receiving environment tool. The cumulative effects test takes into consideration the effects of various odour sources. These odour sources group into three categories:

• Dispersed industries.
• Different clustered industries.
• Clusters of similar industries.

The source-pathway-receiving environment tool gives guidance on determining the level of hazard posed by:

• The odour source.
• The effectiveness of the exposure pathway.
• The sensitivity of the receiving environment. 

Furthermore, this tool enables the calculation of a risk score.  Depending on this score and the quality of the evidence used, the risk assessment can identify further steps to take in reducing this risk or assessing the issue further.

Level 3 assessment

This provides detailed risk assessment tools for issues that are complex. It can also be used where the other levels of assessment have been exhausted. This is when there is not enough evidence gained from the other two levels to establish what the odour risk is.  The value of a risk assessment is enhanced if there are various independent lines of evidence that support each other. 

Other assessment tools

It is not a step-by-step process, and our guidance lists several different tools which may be used to assess odour. The tools include:

• Comparisons with similar operations or case studies.
• Risk assessment using field odour surveillance data.
• Complaint assessment.
• Odour complaint case study.
• Community odour surveys/questionnaires and odour diaries.
• The use of dispersion modelling.

Resources on odour control

• Learn what the law says about odour 
• Read about common types of odour controls
• Read about site planning and management
• Download guidance for assessing odour (publication 1883)