AGCO requires Ontario races to stop at AQHI 7 or higher
Source: AGCO (Ontario)
The Alcohol and Gaming Commission of Ontario says associations must cancel or postpone official workouts, qualifiers and races when the Air Quality Health Index reaches 7 or more, based on the nearest Environment Canada monitoring station. Races must also be cancelled when a specified extreme temperature is reached; associations identify their weather source for other measurements each season.
The thresholds require racetracks to cancel or postpone events under specified air-quality and temperature conditions.