Chemical and Physical Papers. 37 



STANDARDIZATION OF INSECTICIDES AND 

 DISINFECTANTS. 



> By L. E. Sayre. 



AT the last annual meeting of this Academy the writer presented 

 a brief review of the commercial insecticides, and referred to 

 federal regulation No. 16, which requires certain ingredients of 

 these compounds to be declared. Prominent among the constituents 

 affected by this regulation is that of arsenic and any of its com- 

 binations. 



Inasmuch as this class of agents, and those closely related, the 

 bactericides (disinfectants), have come under the regulation af- 

 fecting standards, I have thought it wise to present to this Academy 

 in compact form the present legal status, so to speak, of these two 

 classes of agents, so that we shall have for reference in our report 

 of proceedings reliable data concerning them. In order to do this 

 I may have to revise and add to what was stated on this subject in 

 a paper presented to this Academy last year. 



In the first place, it should be stated regarding insecticides, that 

 insecticides other than arsenical combinations and fungicides con- 

 taining inert substances which do not prevent, destroy, repel or 

 mitigate insects or fungi, must bear a statement on the label of the 

 name and percentage of each inert substance therein, unless the 

 name and percentage of each active ingredient of the article is 

 plainly and correctly stated, in which case it will be sufficient to 

 state on the label that the article contains l^inert substances, giving 

 correct percentage thereof. 



The enactment of the federal law has naturally drawn much at- 

 tention to the subject of the relative value of fumigants, sprays 

 and powders acting as insecticides, and recent investigation of 

 these in our own laboratory has shown that our opinions must be 

 revised as to relative toxicity of members of this class. For ex- 

 ample, it was believed at one time that formaldehyde ranked in the 

 first class among these agents. Actual experiments, however, in- 

 dicate that it is quite low in activity; for instance, it has one-tenth 

 the power of sulphur dioxide. 



For our work on insecticides, "Bell jar experiments" were car- 

 ried out, such as described by Hamilton and Lowe.^ This ap- 

 paratus ie so constructed as to make possible the measuring of 



1. See Journal of the American Public Health Association, 1911. 



