FIELD C 

 Column 1 1 



SOLVENT OR VEHICLE 



Organization 



The items of Field C are solvents and vehicles which have been encountered during the period 

 of CBCC coding. The list has been found generally adequate, but there remain 11 symbols (exclusive 

 of zone punches which may be used alone) available for additions. For this edition, the solvents have 

 been arranged by alphabetical sequence. 



Only liquids (or solids such as fats, with melting points fairly close to room temperature) have 

 been included in Field C. Solids (charcoal, Bentonite, talcum, solid foods, etc. ) are considered 

 merely "fillers", are assumed to be inert, and are not materials that can "carry" the test compound to 

 or into the test organism in the same sense that liquid materials are "carriers". The fact that the test 

 compound may be diluted by a solid "filler" is indicated by appropriate coding in Field A rather than 

 Field C and in the written abstract of the Code Sheet. 



General Use 



Solvents or vehicles are expressed in Field C. The purpose of the field is not primarily to 

 record the solubility property of the test compound (which information is more appropriate on the 

 chemistry records), but to record the material in which the compound is distributed. By virtue of being 

 the material "carrying" the test compound to or into the test organism, the solvent or vehicle used and 

 its relative efficiency may be most significant in the outcome of a test. 



Specific Directions and Explanations 



1. The test compound in a non-living host or host environment coded in Field J 



When the test compound is dissolved or suspended in a culture medium or solution coded in 

 Field J as the test environment, it is not necessary to code anything in Field C. 



As a result of such applications to the habitat or culture medium coded in Field J, the test 

 compound diffuses through the host and reaches the test organism in a lower concentration than that 

 applied to the host. If the concentration after such dilution is known , that is preferably the dosage 

 coded in Fields M and N. For coding of this dosage and Field C, consult Fields M and N, Specific 

 Directions and Explanations section, Division 7. 



2. Solvent MIXTURES; solvents and VEHICLES; STOCK SOLUTION solvents; solvents 

 EVAPORATED to leave residues of the test compound 



If more than one solvent is present (e. g. , 95% alcohol and 5% water or 75% acetone and 

 25% alcohol), one of the following procedures is used: 



(a) When solvent mixtures are present, do not attempt to code any specific solvent. Code 

 "mixture", Symbol A 



(b) When both a solvent and a vehicle occur (as in emulsions, in which a compound is dis- 

 solved in a solvent which is emulsified in the vehicle), code the continuous phase, i. e. , the vehicle 

 (the substance that "carries" the compound and its solvent to or into the test organism), in Field C. 

 The actual solvent of the test compound is to be recorded in the written abstract portion of Field C. 



(c) Compounds are frequently dissolved in alcohol, acetone, or other solvent to provide a 

 stock solution from which a given dilution is made with water, particularly in tests with aquatic 

 organisms (fish, snails, etc. ). In such cases, the aqueous diluent is coded in Field C, with 

 Symbol R. 



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