On Sunday, July 19, while many were viewing the world’s most watched sporting event, a concerned group of Hamilton residents hosted a community information session and discussion about the impacts of industrial pollution and soot in Hamilton. Soot is a constant concern for Hamilton residents who live near the industrial north end, but during the first week of July a larger area of the city was impacted. The soot even reached the homes of some Hamilton mountain residents.

The incident is being investigated and it is currently unknown if a company will be identified and fined.

What is known is that it’s not acceptable for residents to be exposed to industrial fallout in their communities. Industrial air pollution has been an issue for decades in Hamilton and it’s time to clean up Hamilton’s air for good. Here are some of the themes that were discussed by community members during the meeting on Sunday:

1. What is soot? Where does it come from?
   1. What's The Grime
   2. Site Specific Standards
2. How to report soot and/or irregular industrial pollution.
3. What can we do to minimize the impact of soot and air pollution?
4. Recent History and Initiatives
   1. 2024 Soot Incident
   2. 2025 Soot Study Motion and 2026 Report
   3. Environment Hamilton Clean Steel Campaign
5. Experiences - Community Liaison Committees
6. Experiences - Soot Sampling
7. Other relevant soot info and projects
8. More Resources

1. What is soot? Where does it come from?

Soot is a byproduct of the incomplete burning of organic (carbon-containing) materials.

In Hamilton there are many industrial facilities that burn carbon-based compounds. The largest is ArcelorMittal Dofasco, which is an integrated steel mill that features a coke plant to process coal and blast furnaces where the coke is used to melt iron ore and make steel. Stelco (owned by Cleveland Cliffs) also has a coke plant, but no longer produces steel from blast furnaces (the Lake Erie Stelco location does). Smaller facilities like Rain Carbon (coal tar) and Birla Carbon (carbon black) make use of industrial carbon-based byproducts to produce their own products.

Other causes of soot in Hamilton include road dust (especially from large trucks), freight trains, traffic exhaust, and fugitive dust that the wind can blow off storage piles at industrial sites. Industries often spray water on their storage piles, but extreme heat caused by climate change increases the evaporation of water which can lead to more dust.

1.1. What's The Grime

Environment Hamilton partnered with researchers at McMaster University to conduct a study called “What’s The Grime?”. Between November 2024 and November 2025, researchers and volunteers placed soot collection kits at 50 locations in Hamilton neighbourhoods. They found that the chemical profile of the soot closely matched the profile of industrial emissions and that this was especially true for communities located closer to the industrial area.

1.2. Site Specific Standards

The Ontario Ministry of Environment, Conservation, and Parks (MECP) issues site-specific standards and/or technical standards for industrial facilities based on economic or technical feasibility.

Site-specific standards are exemptions from Ontario’s baseline/general air quality standards and act as an upper pollution limit for specific industrial facilities. They expire and get reviewed every 5 or 10 years. Technical standards are also exemptions from Ontario’s baseline air quality standards. Technical standards set requirements with respect to equipment and upper pollution level limits for all facilities in a particular industrial sector and have no set time period for expiry.

The following Hamilton facilities have active or expired site-specific standards or technical standards in place for their air pollution emissions. These facilities are key sources of soot.

Note: if viewing on a mobile device, you may need to rotate the screen to view all table columns.

• Sources: we used information from a 2023 Public Health Staff report and double checked the Environmental Registry of Ontario database.

Extra Note on Site-Specific Standards

For many facilities in Hamilton, the site-specific standards have expired, which means these facilities are out of compliance with Ontario’s air quality laws. Instead of requiring applications for new site-specific standards, the MECP has accepted abatement plans. Abatement plans are supposed to recommend steps that a company will take to prevent discharges of contaminants from resulting in a contravention of Ontario’s air quality standards, but facilities in Hamilton with expired site-specific standards are not preventing discharges of contaminants that contravene Ontario’s baseline air quality standards.

Since abatement plans are not submitted for public comment and review there is a severe lack of transparency and accountability with respect to how air quality is currently being regulated in Hamilton (as well as other communities in Ontario).

2. How to report soot and/or irregular industrial pollution

• MECP Hamilton District Office
  • Tel: (905) 521-7650
• MECP Spills Action Centre
  • Tel: 1-866-663-8477
  • Email photos to: [email protected]
  • Or fill out the online pollution and spills reporting tool at the following link: https://report-pollution.ene.gov.on.ca/
• Contact industry directly:
  • ArcelorMittal Dofasco
    • Tel: 905-548-7200 x0
    • Email: [email protected]
  • Stelco
    • Tel: 905-528-2511 x2268
    • Email: [email protected]
  • Rain Carbon
    • Tel: 905-544-2891
    • Email: [email protected]
  • Birla Carbon
    • Tel: 905-544-3343
    • Contact form submission page: https://www.birlacarbon.com/contact-us/

Important pieces of information to include in your report are:

• The date and time of the incident
• The location of the incident (more specific is better)
• The type of weather conditions
• How you and/or the environment is affected by the incident
• A description of what you are reporting and accompanying photos
  • E.g. discoloured smoke plumes (such as very dark plumes or colours aside from white and dark grey)
  • E.g. larger than usual smokestack plumes
  • E.g. soot prevalence at your home or in your community

For more details see: environmenthamilton.org/air_quality

3. What can we do to minimize the impact of soot and air pollution?

• Clean soot from surfaces:
  • Be mindful of oral exposure.
  • Skin exposure to soot is not an urgent situation, but it is good to clean it off.
    • Soot can often smear when you try to wipe it instead of clearing from your skin or a surface.
    • Residents report that household soaps such as dish detergent can remove soot more effectively than usual shower and bath soaps.
      
      
• Use an air purifier:
  • MERV 13, HEPA, or higher filter rating is recommended, but anything is better than none.
  • Homemade filters can be just as good or even better than air purifiers that you can purchase at the store. See the link below for a guide to make one.
    • https://cleanaircrew.org/boxfanfilterfaq/.
  • See this guide if you are considering buying an air purifier rather than make your own.
    • Choose only air purifiers that have mechanical filtration (particulate filter media). Watch out for ionizers that can produce hazardous ozone.

• Hold industries accountable:
  • Make reports.
  • Take pictures of what you are wiping.
  • It may not feel like much, but it does have an impact when industry and the ministry receive reports from residents, especially when they receive many reports at once.
  • In response to reports when a specific site is identified, employees will investigate operating conditions and find a problem that can be fixed to bring operations back to normal.
    
    
• Longer term, advocate for fossil-fuel-free industry and better pollution controls:
  • The only way to completely remove the hazard is to clean up the source.
  • We need governments to pursue a fossil-fuel-free industrial strategy and a clean energy transition program for workers whose jobs may be impacted. The billion dollar companies won’t do it unless they are forced to do it.
  • If interested, you can sign up at environmenthamilton.org/steel to get more involved with our advocacy efforts. Someone from our team will get in touch with you after you sign up.

4. Recent History and Initiatives

4.1. 2024 Soot Incident

In 2024, Hamilton residents in some neighbourhoods experienced a similar incident where soot was much more noticeable than usual. The following text comes from a Hamilton Public Health report written after the incident:

“In 2024, residents in Wards 2, 3, and 4 submitted complaints regarding black fallout in their neighbourhoods to the Ministry of Environment, Conservation and Parks.

Accordingly, from February to October 2024, the Ministry of Environment, Conservation and Parks sampled and analysed black fallout where a complaint was received in City of Hamilton Wards 2, 3, and 4 with a total of 54 samples collected.

The samples were analyzed for coal, coke, kish/magnetite, minerals, biological matters, synthetic fibres, graphite and others. A majority of the samples showed traces to nondetectable concentrations of various analytes tested. However, 16 sample locations revealed detectable concentrations of coal, coke, magnetite, minerals and biological matters.”

The MECP never made the full results of this report publicly available. We are pushing for the report written for the latest soot incident to be made public once the investigation is complete.

It’s important to note that the MECP does point-in-time sampling during irregular emission incidents to try and identify the specific facility that has caused the pollution. One drawback of this type of sampling is that the samples are not always large enough for laboratory analysis, which is part of the reason only 16 out of 54 samples came back positive (although 16 out of 54 is still concerning).

The “What’s the Grime?” study sampled over a period of three months to one year. This sampling method yields larger and better samples for lab analysis but the long sampling period means it cannot be used to investigate unique incidents at individual facilities.

4.2. 2025 Soot Study Motion and 2026 Report

In March 2025, the Ward 3 and 4 City Councillor offices brought forward a motion at the Board of Health to direct Public Health Services' staff to work with a third party vendor to develop a feasibility study with options to perform particulate matter (black soot) residue sampling and testing in Wards 2, 3 and 4 in the city of Hamilton. This was moved in response to the poor MECP reporting of the 2024 soot incident.

Public Health staff found a third party contractor in September of 2025 and the feasibility study was not presented to the Board of Health until May 2026 (along with a staff report). The study was lacking important details. Community members delegated at the Board of Health meeting in May and June 2026 expressing concern that the engineering firm lacked the competency to do proper testing to help residents and that if the proposals outlined in the feasibility study were implemented, it would not provide the community with useful information. For example, the firm wrote that it would sample particulate matter in the air with a collection method used to sample gases.

To ensure funds are spent in a way that helps residents, the Board of Health decided to consider alternative options before moving forward with a soot study.

4.3. Environment Hamilton Clean Steel Campaign

Environment Hamilton is closely monitoring progress (or lack thereof) on the coal phase-out project announced by ArcelorMittal Dofasco and the Government of Canada in 2021. The Government of Canada and Government of Ontario pledged $450M and $500M towards this project, respectively.

We are also monitoring pollution impacts of other local steel industry facilities and advocating for a clean energy transition that supports workers. If you care about the environmental impact of the steel industry, sign up at the link here to stay up to date and get more involved.

Click here for a timeline of events regarding ArcelorMittal Dofasco’s 2021 coal phase-out announcement.

On June 22, the City of Hamilton Board of Health passed a motion requesting the province to reject ArcelorMittal Dofasco’s pending application to renew its Environmental Compliance Approval (ECA) for air pollution. The Board also requested better air quality monitoring around Dofasco’s fence line and reaffirmed its opposition to special air pollution permissions granted by the Ontario Ministry of Environment, Conservation, and Parks (MECP) for industrial facilities. As long as ArcelorMittal Dofasco is operating under an abatement plan instead of meeting an air quality standard, new environmental compliance approvals should not be granted. It is good that members of the Board of Health unanimously agreed. More here: https://www.environmenthamilton.org/steelupdate-2026-07-09.

5. Experiences - Community Liaison Committees

Some of Hamilton’s largest industrial sources of air pollution are required to hold quarterly Community Liaison Committee meetings that are open for any resident to attend. Residents can voice concerns directly to company staff at these meetings.

You can find more information to attend the Stelco and Dofasco community liaison committee meetings at the links HERE (Stelco) and HERE (Dofasco).

Some community information session attendees had extensive experience attending community liaison committee meetings. These were their tips:

• Don’t be afraid to ask questions.
• Don’t be afraid to voice concerns.
• Speak from the heart.
• Attend in-person if you can (Dofasco and Rain Carbon do hybrid meetings, Stelco meetings are currently fully online).
• It helps when more people attend.

6. Experiences - Soot Sampling

A community member noted that when you report soot at your home to the MECP, the MECP could contact you so that they can come and sample it. Residents can ask for the results of their sample. You do not need to file a freedom of information (FOI) request to get the results of a soot sample taken at your home.

7. Other relevant soot info and projects

Government Inaction

There is a long history of the Ontario Government being complacent on air quality no matter which political party holds power.

In 2009, the provincial Liberal government agreed to address the issue of cumulative air pollution in response to consistent advocacy by members of the Aamjiwnaang First Nation. In Ontario, the pollution from an industrial facility is considered in isolation from the other industrial facilities that may exist next to it and so the combined impact of all industrial facilities on residents is not considered.

A cumulative effects policy was not introduced until 2017 and it was extremely limited. It only applies to Hamilton and Sarnia, only for air emissions of benzene and benzo[a]pyrene, and only for new facilities or expansions.

The provincial government was supposed to review the policy after two years but still has not. The Canadian Environmental Law Association has filed a request for review in collaboration with a member of Aamjiwnaang First Nation and Environment Hamilton.

Another program introduced by the provincial liberal government was the Environmental Activity and Sector registry. It was introduced in 2010 to streamline the environmental approvals process for smaller industrial facilities that are lower risk and undertake less complex operations. This policy makes it more difficult to hold smaller facilities accountable:

• There are no up-front reviews by MECP staff.
• There is no public oversight as these approvals are exempt from the Environmental Bill of Rights public notice, comment and appeal provisions.

Passive Air Quality Study

In 2022 and 2023 Environment Hamilton partnered with the Dr. Matthew Adams U of T research group to conduct Hamilton's largest passive air quality study. The study found that everyone in the City of Hamilton is affected by air pollution and that the impact increases for folks living closer to the north end industrial area. For more information you can view the page linked here.

8. More Resources

Facebook groups: 

• Citizens Against Pollution
  • Communicates quarterly community liaison committee meetings and a place to share smoke stack photos in the event of irregular emissions.
• Hamilton Residents for Clean Air
  • Created just before the community information session took place.
  • Community members who want to take action and reduce air pollution in Hamilton.

Industrial Air Quality Tracking:

• Hamilton Air Monitoring Network (HAMN)

Environment Hamilton StackWatch tips and pollution reporting information:

• https://www.environmenthamilton.org/air_quality