What is odour?

Odour is the sensation when receptors in the nose are stimulated. The human nose is sensitive, with approximately 400 types of scent receptors, and can detect smells at very low concentrations.

Individual responses to odour are subjective – an odour that is pleasant to one person may not be to another. Smelling an odour is not a reliable way to tell whether it could affect a person’s health. Whether you experience a health effect depends on the substance that is causing the odour, intensity, how long the odour lasts in the environment and whether you have sensitivity to a particular odour.

Most odours do not pose a health risk, but exposure to some can lead to headaches, nausea and other symptoms.

When the government gets involved

The Environmental Protection Act (EPA) gives the Ministry of the Environment and Climate Change the authority to respond to odour concerns under the following three circumstances:

  • there is reason to believe that a discharge into the environment is causing or could cause harm to the natural environment or a person, a loss of enjoyment of the normal use of property, or interferes with the normal conduct of business (Section 14 of the EPA)
  • if a discharge released into air from an industrial, commercial or other source exceeds a standard. There are standards for some odorous contaminants, set out in Ontario Regulation 419/05 – Local Air Quality
  • most industrial facilities require an Environmental Compliance Approval (ECA). This puts strict requirements on how these facilities operate in order to protect the environment. Depending on the type of facility, the ECA may include specific requirements to control odour. The ministry inspects facilities that are required to have an ECA

Reporting an odour

If you experience an offensive odour in your community, record it in a daily journal. This information will help the ministry assess whether action needs to be taken.
Your journal should describe the following:

  1. quality of the odour: if the odour is offensive, please describe using descriptors such as fragrant, sweet, oily, paint, solvent, septic, rotten, medicinal, musky or musty
  2. intensity: this is rated on a scale from one to five. Is the odour very weak (1), weak, distinct, strong, or intolerable (5)?
  3. frequency: how often is the smell present? Once during the day or more? Note the days as well as the time
  4. duration: how long does the smell last? Be precise in describing the duration
  5. weather conditions: was it windy? If so, in what direction was the wind blowing (e.g. south)? Were the winds calm, moderate, breezy or strong? Was it sunny, cloudy or raining? What is the temperature?
  6. source: where do you think the odour is coming from? Why?
  7. how is the odour affecting you?

If you believe an odour is affecting your health or the environment, you can contact your local district office of the Ministry of the Environment and Climate Change. You may also wish to contact the company that you believe may be responsible for the odour.

Odours from spills

Sometimes an odour may be due to a spill from a pollutant such as gasoline, chemical acids, sewage and dust, into the natural environment from a structure, vehicle or other container. If you believe that an odour you are experiencing is from a spill, you can report it to the Ministry of the Environment and Climate Change Spills Action Centre (SAC) by calling:

1-800-268-6060 (toll-free, province-wide, 24/7)
416-325-3000 (Toronto area)
1-855-515-2759 (TTY)

Odours from farms or other agricultural operations

If you believe that you are being impacted by odour from a nearby farm or agricultural operation, you may wish to speak with the farmer whose operation is believed to be creating the odour. Many complaints are resolved this way.

If the complaint is not resolved, you can seek assistance from the local Municipal Agricultural Advisory Committee or the municipality. If further mediation is still needed, you can call the Ontario Ministry of Agriculture, Food and Rural Affairs Agricultural Information Contact Centre at 1-877-424-1300. Staff will arrange for an agricultural engineer or environmental specialist to contact the parties and facilitate a conflict resolution process.

The Farming and Food Production Protection Act (FFPPA) protects farmers against complaints made by neighbours about nuisance disturbances such as odour if the farmer is following normal farm practices. For more information on the FFPPA and responding to nuisance complaints, please read the factsheet: The Farming and Food Production Protection Act (FFPPA) and Nuisance Complaints.

Responding to odour complaints

In order for the ministry to take action, an environmental officer should reasonably believe that action to control the odour is necessary. The environmental officer will assess:

  • the magnitude of the odour: how significant is the smell?
  • the location of the odour: is it coming from a fixed location or is it mobile?
  • the source of the odour
  • the substance or the process causing the odour
  • if from a facility: does the facility have the proper ministry approvals?
  • if from a facility: is the smell related to normal operation of the facility or from a spill?

With this knowledge and information from the community, the ministry may require the facility to take steps to manage or control the odour.

When your local government gets involved

There may be sources of nuisance odours in your community that do not cause health impacts, such as those from some commercial operations (e.g. restaurants). The Ontario Municipal Act gives municipalities the authority to regulate nuisance odours. Municipalities also have bylaws that govern zoning, operational permits, licences and waste handling (which may be a source of odour). Contact your city hall or municipality for more information about these bylaws.

If you have health concerns

If you have health concerns as a result of exposure to odour, please contact your local public health unit. It may be helpful to provide the health unit with information that you track in your journal.