Although the new Hi-viz rules in France aren't due to be enforced until Jan next year, the necessity to carry a disposable breathalyser will be live from 1st July this year.
Alcohol is a factor in more French accidents than speed is, but generally involves those extreme offenders who are 2 or 3 times over the limit. The French limit is 50mg per 100ml of blood, as opposed to our UK 80mg level, so it is remarkably easy to be over the limit with perhaps one drink, dependant on circumstance.
Obviously not drinking at all before riding, is the best practise, but now you will be penalised regardless of alcohol consumption, but rather the carrying of something to test whether or not you are over the limit! Even T-Totallers are going to fall foul of this one.
The fine will be 11 Euros so is clearly just an income stream as compliance can be checked in association with any other offence or stop and check situation. The units themselves can be bought for about 2 Euros and will be available at ports and on ferries.
Bear in mind, many of these new laws affecting motoring in France may be in jeopardy anyway, depending on the results of the elections that will be running in April. The opposition are aware just how unpopular they are and may well overthrow them before they are enacted.
If you are planning a trip this summer, please remember that as things stand, compulsory headlight use exists, as does carrying a set of spare bulbs and you should probably ride on the right.... The 4 reflective stickers on your helmet is a rule that has been in for about 10 years, but I've never heard of a case of the police enforcing it for non-French Nationals.