Hissing?

I have had my bp for about 3 weeks now and last night while I was sleeping he tipped over his water dish. He's in a sterelite tub which i keep at 90 and 80. The humidity is always a little on the high side (65-70ish usually, i lower it if it goes higher) but this morning when I got up to check on him because of the water dish it was about 85% humidity. I don't know how long it had been but I let it air out a bit, wiped down his hide and switched his substrate out. I just fed him and he's been sort of hissing... it's more like sighing. I guess I'm wondering how soon I should worry about RI or if it's a digesting thing or something. Thanks!!

85% humidity for 4 to 8 hours is is not going to give him an RI.

More than likely you are hearing him just breath heavily. It sounds like a hiss but isn't as long as one and typically isn't repeated consecutively like a his. Think of it as a grunt or groan but with no pain or anger behind it.