I am more concern about the vapours as the travel size one I have consume very little power

Very interesting. I do not know how cross-national aviation laws work, but I'm sure if CX wants to travel to USA they need to honor FAA rules, and I am told specifically that FAA has ruled any pax that requires the use of CPAP MUST BE ALLOWED TO DO SO on board any plane, no airline can discriminate against a pax that requires the assistance of CPAP as long as the model of CPAP they have has the sticker or documentation that is "FAA-approved."

Sleep Apnea is a seriously thing, pax with Severe Obstructive Sleep Apnea are even at risk of death if they don't use their CPAP regularly.

At least in the context in which you reference, incorrect.

Wow, something needed to be fixed or at least talked about. One nation allowing CPAP and another nation does not.

Just flew back on 889. Used CPAP without question asked. I did however got preclearance from MPO.

Since there is no organization that can dictate regulations to all countries, it will remain a country-by-country issue.

As per the link provided by Bob7032 and our operations manual:

-For CPAP devices; get preclearance 48hrs before hand to avoid issues.

CPAP device details:
-If flying to/from the US, the device must have a manufacturer's label stating the device is FAA approved. All FAA approved devices will be automatically accepted on any/all flights in the CX network.
-Devices without an FAA approved manufacture's label, but on the CX approved list (call reservations for this) will be accepted only on flights that do not go to/from the US.
-All other devices not falling under the above will require assessment and approval from CX engineering prior to use (and will only be allowed on flights not involving the US, once again)

Usage:
-Stowed for taxi/takeoff/landing etc, like any electronic device.
-May be used with in-seat power sockets, with the note that these are not guaranteed to provide enough current nor be 100% serviceable on 100% of the aircraft. Sockets are the multiplug type fitted to all long haul config aircraft in every seat, supporting US,UK,AUS,Euro etc plug types.
-May be used in conjunction with a humidifier function assuming that it's a closed-circuit type - ie, no visible vapour (take note correctioncx)

Recommendations:
Get a battery powered FAA approved unit, call 48hrs before hand and you'll always be good.

Hose head
 

I used a CPAP machine on literally dozens of CX business and first class flights over a period of many years without incident. Last year, late at night on a flight to HKG from YVR in business, a flight attendant shook me awake and told me I could not use the device and demanded I immediately turn it off. She stood over me waiting and was quite agitated and loud, getting in my face and waking up other passengers. This was embarrassing and unnecessary. I eventually told her I was fine without her watching me, to leave me alone and to have the senior flight attendant come over for a chat. Much apologising ensued.

Still, the experience put me off using CPAP while flying, which I'm sure has led to my fellow passengers being inconvenienced by snoring. I looked into getting permission to use CPAP onboard, but it appeared to be an onerous amount of paperwork for each flight. I also dreaded being shaken awake by another FA. The rules, such as they are, are obviously not well known or always applied equally by the crew.

CX seems to have modified it's rules on CPAP recently and now suggests getting a "FREMEC" card that allows me to fly without getting advance clearance. All I need to do, apparently, is get a form filled in by my doctor once, then a card will be issued allowing me to use CPAP onboard.

Any hose-heads out there who have applied for a FREMEC and are willing to share their experiences? Please tell me you don't have the FA come over at the start of the flight and treat your medical condition like ordering a special meal: "Hello Mr. X. I have you down as a sleep apnea passenger. Will you be using any devices today?"

Any other pointers on CPAP use while flying CX?

Thanks in advance.

Also, what's the big deal that airlines want to regulate usage? Too loud? Not the case as many CPAPs are ultra quiet. A risk of explosion? Again not the case. Too much power drain? Maybe, but on a modern heavy plane with much power to spare? Why the antagonistic attitude towards CPAPs?

Potential for fire and/or electrical interference.

That's a good question. Certainly no more fire and electrical interference risk than any of the other gadgets people bring on board. At least I'm not using my CPAP during take off and landing. I've seen people babbling away on their cell phones and pounding out text messages as the plane rolls down the runway.

Anyone out there who has used the FREMEC option? Still interested to know if it alleviates the need for a call to CX before each flight.

As a medical device especially designed for people sleeping at night with no wifi/bluetooth capabilities CPAP has the least fire and electrical interference then dozens of electronic gadgets people bring on the plane nowadays. If this is truly the reason it's one of the most ignorant reason ever.

I think they want advance information to be able to ensure in-seat power instead of risking having to move someone.

While that may be your opinion, it is inconsistent with general aviation safety protocols.

CPAP machines have motors. iPads don't. Motors create electrical interference as a byproduct of their operation. Motors are also more likely to create sparks, shorts, and create a fire risk.

If you have an FAA approved machine, it has been checked to ensure it is shielded and safe for aviation use. Just because a CPAP has not created a problem in the past is not the test for aviation safety. The device must be certified that it has been tested and is safe.