Dangerous?

Well, the smell might be lingering, but you will live!
It's certainly better to not throw it down the drain and it's also better to not breath it in, but it is not that bad if you would smell it a few times. Give it one or two times using the shower andit is gone.

I find the developer doesn't emit odors, especially compared to the stop bath.

I wouldn't worry.

Perhaps something in the drain, soap, hair, bacteria, spit, whatever got excited and said, "I'm gonna stink for you!" Maybe clean the shower drain? Or dump the stuff down the sink?

I'm just worried that it will make us ill. I'm also slightly worried about absorbing it through skin, quite a bit spilt over my hand, I tried to wash it straight away. Can that do anything?

No danger there!
You off course shouldn't bath in it. But some over your hand or a bit of smell is part of the darkroom experience. Don't worry that much about it. I had it over my hand often, putting the liquids in bigger containers to bring it away. Just wash the hand with soap, no issue.

Oh thank you, Dennis. I've never done it on my own before... only at university.

While you most likely have nothing to worry about, not all chemicals are the same and some can cause problems, though usually not typical developers and fixers. I would take the time to look up the MSDS's for the chemicals you are using and skim through them.

You can also always pick up a box of nitrile gloves for $4 and where them while developing if you are concerned.

If you want to do some fun experiments, have a look at the following fun ways of experimenting with developing your film:
Developing with coffee or Vitamin C: http://www.digitaltruth.com/data/caffenol.php
Have a look on the forums of photo.net. There has been a lot of discussion on this one. Red wine and washing soda is good fun as well...

Thanks Tim - I looked them up for the Ilfostop and Ilford Microphen. They seemed okay, from what I can see...

Beth,

Photo chemicals are mainly water. The developer solution contains a mild alkaline that sets the pH high. The developer itself is a derivative of benzene. The other constituents are in trace amounts. The major harm, photo waste like human waste, has an oxygen demand. As it travels along the sewer it absorbs oxygen. So you added the demand of about one person visiting and using your bathroom.

The stop bath is vinegar about the same strength as table vinegar. The fixer is also vinegar plus a salt of sodium or ammonium. No worry its main effect is also oxygen demand.

Now the municipalities don’t like sliver. A trace will be found in spent fixer. They don’t like it because it is a heavy metal and heavy metals are presumed to be toxic. The toxicity of heavy metals cannot be disputed however the silver, in this case readily converts to silver sulfide. This happens after the stuff travels about a kilometer. If it does not convert in the sewer it will be converted in the treatment plant. The good news is silver sulfide is inert.

As to you and your family’s health, the main cause of distress is contact dermatitis. A rash some people surfer that comes from constituents of the developer. Color developer is most likely to cause. Once affected, you will unlikely need to stay away forever. Happily this is infrequent.