Various types of solder have been developed that do not contain colophony (which is a well known cause of occupational asthma).
There have been a small number of cases of occupational asthma to these, although they are still considered to be an improvement.
Please see the subcategories on the right for specific types on non colophony solder. Please note that the linked references search for the word "Solder" where the words "Colophony" and "Resin" are not present. This will include some results for solder containing colophony (apologies).