I have had a discussion with Air Canada about medical reasons for being unable to wear a mask and how to obtain an official exemption that would help avoid conflicts with gate agents, check-in agents and FAs. I mentioned previously that the mask policy on board is de facto weakly enforced if at all, however in my experience the gate and check-in agents are more strict.

I have a respiratory problem that makes long periods of wearing a mask difficult/impossible. A few minutes to get checked in or boarded is fine, but sitting for 4+ hours on a plane with the mask on 100% of the time isn't possible. So far I've been able to avoid major conflicts, but if the day comes that this policy is strictly enforced, I wanted to arrange an official exemption.

If you read the AC CleanCare+ FAQ, they explain as follows:

"This requirement applies to all customers except for children under the age of 6 or customers who have a medical condition preventing them from wearing such a covering. This exemption will need to be verified and approved by Air Canada in advance through a medical certificate or Air Canada Fitness to Fly form. Click herefor more details on how to submit."

The issue with the "Fitness to Fly" form is that it lists a whole bunch of different medical conditions and your doctor is supposed to fill out whatever section applies to you with very specific information. However the "Chronic Pulmonary Condition" section is primarily focused on people who need oxygen to fly or can't walk long distances, and makes no mention of masks. I've told AC that this form isn't well suited to obtaining an exemption to the mask requirement and they should consider updating it. Their reply was the following:

"Please note, you may provide us with a doctor’s letter indicating the condition that prevents you from wearing a mask.

A doctor’s letter is valid for 1 year.

You may email us your letter, with your flight information, and we will add the approval to your booking."

I was impressed that they replied in under 24 hours. So I will obtain said doctor's letter and see what happens.