As long as you don't have any open wounds and used reasonable protection i.e gloves, I think you should be ok. Just be sure to get scrubbed when you're finished. I have done similar in the past and not suffered.
Coolant will usually last about a year I think? But I don't know of many companies that change coolant in a machine yearly due to the cost of disposal. It usually gets done when it really needs it. It also depends how often it is being used. If it is left to sit, then the bacteria gets a chance to grow.