I'm not a doctor, but from what I understand the only exposure you need to worry about would be from the actual urine discharge for up to 8 hours after BCG instillation into the bladder. Most seem to recommend pouring bleach into the toilet for up to 8 hours after BCG therapy and using disposable rubber gloves. I myself (while going through BCG therapy) made sure I had a restroom I did not share with anyone else for 12 hours or so, kept it locked (so no children could be exposed or the dog couldn't drink out of the toilet), and made sure I wiped it down with clorox bleach and made sure to add bleach into the toilet for 15 minutes before flushing to kill off any residual BCG.
The guidelines I have seen also restrict sexual intercourse with someone who has had BCG therapy for 48 hours and suggest using a condom for the duration of BCG treatment and up to a month after.
Its mostly all just precautionary and I do not think the risk of infecting others is too great, but better safe than sorry. I mean us patients are being exposed by having the stuff poured and retained into our bladder for two hours and its very rare that the patient ends up getting an infection from BCG.
Chris A.
Diagnosed T1G3 - 3/01/06
37 yo, Seattle, WA