Posted on October 27, 2017 (updated: June 20, 2019)

Statement — Ecojustice reacts: Sulphur dioxide air quality standard to be updated for first time in 43 years

TORONTO — Ecojustice commends the Ontario government’s decision to finally update its sulphur dioxide air quality standard to a level that protects human health, but calls for a faster phase-in and province-wide application.

“We commend the Minister on moving forward with a proposal to reduce Ontario’s sulphur dioxide standard by 85 per cent. But the government must act swiftly to bring the new standard into force to protect public health across the province,” said Dr. Elaine MacDonald, Healthy Communities program director at Ecojustice.

Air quality standards in Ontario are used to regulate industrial emissions to protect local communities.

Ontario is proposing a 5-year grace period before the updated one-hour and annual standards apply to industrial emissions. In 2016, Ontario held meetings with stakeholders and committed to updating the 43-year-old standard by the end of the year, but efforts had stalled up until now under heavy industry lobbying.

The proposal also clarifies how the standard will apply to various operating conditions at facilities  including industrial flaring.

“Five years is far too long to wait given the seriousness of the public health threat posed by sulphur dioxide. Facilities throughout Ontario must be held to the health-based standard sooner,” MacDonald said.

Elevated concentrations of sulphur dioxide are known to cause respiratory and cardiovascular distress, particularly in vulnerable populations including children and people with asthma. Respiratory distress from sulphur dioxide exposure can occur very rapidly, even within a few minutes.

The proposed update will bring the current Ontario one-hour standard from 690 µg/m3  (microgram per cubic metre of air) to 100 µg/m3, representing an over six-fold reduction. This would place Ontario’s sulphur dioxide standard at a level Health Canada has identified as sufficient to protect public health including vulnerable individuals. Ontario is also proposing a non-binding 10 minute criteria of 180 μg/m3 and a binding annual standard of 10 μg/m3 to protect crops and vegetation.

The old, poorly enforced sulphur dioxide standard has troubled Sarnia’s Chemical Valley and Aamjiwnaang First Nation, where residents are frequently exposed to sulphur dioxide  and other pollutants from multiple refineries and petrochemical plants. A high number of community members suffer from respiratory conditions like asthma, and regulations don’t protect them from the multiple intense exposures because each facility is given permits without considering the cumulative emissions in the area.

This year Ada Lockridge of Aamjiwnaang First Nation, represented by Ecojustice, took the MOECC to court for delaying its review of how it regulates cumulative emissions.  

In a separate application, Ecojustice is helping Vanessa Gray, also of Aamjiwnaang First Nation, call on Ontario to  investigate a major flaring incident at Imperial Oil in February 2017.

“Flaring of acid gases by refineries and petrochemical plants is an intense source of sulphur dioxide emissions in Chemical Valley that must be subject to the revised standard. Pollution emissions from flaring are poorly regulated by Ontario despite the high risks to local communities,” MacDonald said.

“Updating the standard for sulphur dioxide shows the Ministry is finally on the right track, and we look forward to similar progress on the issue of cumulative emissions and regulation of flaring.”

Last week Aamjiwnaang’s Chief and Council issued a statement that they were “deeply concerned” that delays in updating the sulphur dioxide standard were failing to protect their community’s health and environment.

In a report released this week, Environmental Commissioner of Ontario Dianne Saxe called upon the government to take action and improve the regulation of pollution in Chemical Valley and to update the sulphur dioxide standard.

“Updating our pollution and toxics laws and empowering communities to participate in decision-making will go a long way toward protecting our environment and making Canada a more just and equitable place to live,” MacDonald said.


A recent exposé by Global News, the Toronto Star, and the National Observer used documents obtained by Ecojustice, and uncovered more than 500 excess pollution incidents in a two year period. Of those 500 incidents, more than 100 were related to flaring.

In the wake of the joint news investigation, calls for action in Chemical Valley have been issued by several Canadian politicians, including Green Party Leader Elizabeth May, Ontario NDP Leader Andrea Horwath, NDP environment critic Linda Duncan, Federal Health Minister Ginette Petitpas Taylor, Ontario PC Leader Patrick Brown, and Environment Minister Catherine McKenna.

Diseases caused by pollution are “the largest environmental cause of disease and premature death in the world today,” according to the internationally renowned Lancet Commission. Diseases caused by pollution led to about nine million deaths in 2015 alone — that’s three times more deaths than malaria, tuberculosis and AIDS combined.

In Canada, the number of pollution-related deaths are staggering. 7,700 of us die each year from poor air quality alone. The annual cost of air pollution and the health effects caused by exposure to toxics together, are estimated to be in the tens of billions of dollars.

Several environmental groups, including Ecojustice, Environmental Defence, David Suzuki Foundation, Canadian Association of Physicians for the Environment, and Equiterre are calling for enforceable national air quality standards under the Canadian Environmental Protection Act.


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