I put 1.5ml in a litre (think I used to use 5ml in a litre, but erred on caution!), done the deed & surveyed constantly, completely flea free this morning, remember a couple of year ago, I treated 5 or 6 terriers with not a lot of ventilation, had a bit of a funny turn!
Yeh could be out of date, got a bit of old stock of various rodenticide/insecticide, just use it for my own place/friends now, still active.
Ill get onto an allround tablet from the vet.