There's at least 2 dozen UK species that are capable of biting a human (i.e. actually piercing human skin), including the larger house spiders, big garden spiders (the ones with the 'cross' pattern, above), woodlouse spider, and water spider, basically any of the larger species. However, they generally won't bite unless they have no option - the one that bit me was in my slipper, and bit my toe when I put my bare foot in and trapped it, crushing its leg in the process. What else could it do?
None of them are remotely dangerous though, unless you happen to be allergic. Woodlouse spider is the only one I would hesitate to handle because it has huge armour-piercing fangs and is much more aggressive than most UK species, but that is still pretty placid on a global scale. Spider venom is usually 10 times less toxic to a mammal than an insect, so by the time you factor in the volume of venom they can inject relative to your body size, you see that it is remarkable that any species could do any harm at all.
In the USA, the species Tegenaria agrestis (which occurs in the UK, including Scotland) is reported to have a potentially dangerous bite, and is referred to as the Aggressive House Spider, but that is suspected to be a misinterpretation of agrestis rather than any reflection on its behaviour. There are no reports of anyone in the UK ever having been bitten by one, let alone harmed by one.
Carry on throwing them out. You won't get bitten. But be warned - they come straight back in!
