Ive had that a few times over the years with Bal bond even when Ive have got a new container and first opened it and have not diluted it with water its not a nice smell ,priming the customers bathroom it travels through the house and you have to explain its not you .Once sbr has been mixed with water does it then have a time scale before it goes off. Reason im asking is I normally premix my sbr into 5l bottles 3:1 and when I opened a bottle yesterday it smelt like rotten egg so didnt use it. Anyone had any problems like this?