STANDARDIZATION OF DISINFECTANTS 

 Table V 



251 



Valuable information regarding the comparative toxicity of 

 many substances used as disinfectants may be obtained from 

 a study of the comparative medicinal doses. For example, the 

 medicinal doses of phenol, betol, resorcinol and corrosive sub- 

 limate are i grain, 3 grains, 4 grains and J^o grain respectively. 

 These doses are practically'in proportion to the toxicity of the 

 substances named and stating the dosage in the terms of the 

 phenol toxicity coefi&cient as proposed by Hale, we would get the 

 following results: 



Plienol 100.00 



Betol 33-3° 



Resorcinol 25 00 



Corrosive sub 3000 . 00 



As a rule, however, the exact composition of many of the 

 proprietary disinfectants is either not made known to the users 

 or is not disclosed by the manufacturers and in such cases the 

 only thing to be done in order to ascertain whether or not the 

 claims of the manufacturers are correct, is to make tests as above 

 outlined. However, in cases where the composition of the dis- 

 infectant is definitely known, whether a simple or compound 

 substance, its comparative toxicity can be determined by as- 

 certaining the toxicity of the several ingredients and rating in 

 comparison with the standard, namely, pure phenol. 



