The main ingredient in Timbor, borax, is mined as a crystal (above) of nearly pure sodium borate. Borax has many commercial uses including water softening, flame retardent, glass additive, and as an insecticide/fungicide.
Timbor Specimen Label (pdf file)
A specimen label is the official product label that contains all of the information required for registration in the US and instructions for use.
Boric Acid Factsheet (pdf file)
The National Pesticide Telecommunications Network (NPTN) factsheet for the active ingredient in Timbor.