How long does Smoke's gas canister last for?

How long does the damaging gas last for? Would be helpful for to know as the particles still exist when it's no longer damaging and to know when to start gassing a near the end of the round.

Solution 1:

Short and sweet: the gas lingers for about 10 seconds from detonation until there is almost no visible smoke left. As long as there is some smoke, it will do damage.

So I went and did a bit of testing myself in the Smoke situation level and my findings are as follows:

(I did a few tests of two different methods because human error). Every attempt done was on hitting the middle mouse button to detonate the smoke grenade at the same exact time (as best I could) as I began counting or began the stop watch.

Counting out loud (1 Elephant):

1. 9 seconds
2. ~ 9.5 seconds
3. 9 seconds
4. ~ 9.5 seconds
5. ~ 9.5 seconds

Counting using a stop watch:

1. 9.8 seconds
2. 9.6 seconds
3. 10 seconds
4. 10.1 seconds
5. 9.7 seconds
6. 9.9 seconds
7. 10.1 seconds

From this I feel safe concluding that his smoke lingers from detonation (till there is no visible smoke left) for about 10 seconds. I feel safer using the stop watch numbers as a judgement considering it's a bit more accurate than me counting about elephants out loud.