Know the poisons information centres (13 11 26) in Australia, 0800 764 766 in New Zealand). Read the first aid advice before you begin, it is not a lot of use after the event.
Eye contamination is best assisted by flushing with plenty of fresh water. If some product is swalloed, drink water to dilute the contents but do not make the patient vomit (it may do more damage on its way back). In all cases get to medical help quickly. If anyone is having breathing difficulties call an ambulance.