TORONTO - The NFL and the CFL may have different rules and play different styles of football but they follow a similar protocol when it comes to inflating balls.

It's a touchy subject in the NFL these days as "Deflategate" continues to rage less than a week before New England and Seattle meet in the Super Bowl. The controversy centres around whether underinflated footballs used by the Patriots in their 45-7 AFC title win over Indianapolis gave them an unfair advantage.

While their size specifications differ slightly, footballs in both leagues must be inflated to between 12.5 and 13.5 pounds per square inch and be checked by officials prior to the game.

At least 18 footballs are used per CFL game. The two teams provide six apiece that are stamped with their name and used exclusively by each on offence. These balls must be approved by the referee, who will decide if they meet "new-ball standards."

The home team also provides at least six new and unmarked balls that both teams will use on kickoffs, punts, convert and field-goal attempts. The home squad must also have a sufficient supply of additional kicking balls available if needed.

In the visitor runs out of offensive balls, it uses kicking footballs for the remainder of the game when on offence.

Both teams present their footballs to the referee at least 90 minutes before kickoff. Additional ones can be provided afterwards but must meet new-ball standards to be used in games.

Once the officials get the footballs, they measure them and check the air using an electronic pressure gauge before approving them for play. When balls are in the officials' possession, teams can't access them except for normal, on-field play.

During games, the league has four ball handlers on the sideline and the balls are kept in bags under the control of the sideline staff.

And like the NFL, any CFL team using an illegal football or altering one during a game is subject to fine or suspension.