FIELD T-2 

 Columns 58, 59, 60, and 61 



of the test animal. When Symbol 1142 is used, however, the specific side effects should be designated 

 in the written abstract of Field T-2. 



In spite of the general restriction for coding a side effect (as defined above), specifically and 

 with a separate code line, the CBCC may occasionally make exception when the toxic symptom treated 

 or produced seems to be a particularly significant response to the chemical or when the symptom's 

 response, when treated by the test compound, seems especially significant. 



When the compound produces death (Symbol 11, 111, or 112), there are frequently more or less 

 severe toxic manifestations immediately prior to the actual death (i. e. , symptoms related to and 

 accompanying death). The coding of such death-accompanying responses would require, for each, a 

 separate code line, or several separate code lines, in addition to the line coding death itself. The 

 CBCC prepares only one code line, the line for the lethal response. Any responses that typically 

 accompany the death due to the specific test compound are to be included in the written abstract of 

 Field T-2 of that line coding the death of the organism. 



9. Symbol 12; viability 



Symbol 12 has had a checkered career in the CBCC Code, partly due to the confusion arising 

 from the fact that both an organism's "viability" and its "survival of lethal pathology" are associated 

 with death which treatment with a test compound can affect (delaying, speeding, or preventing death's 

 occurrence). For this reason, there has been a tendency to attempt coding both of these with a single 

 symbol, Symbol 12. Reference should be made to the discussion of survival of lethal pathology, 

 Symbols 1753, 1754, 1621, and 1631, in Division 13. The term, "viability", is not used to express 

 an organism's survival of pathology, but describes an organism's ability to survive normal environ- 

 mental conditions. For example, the term is applied commonly to plant seeds in describing their ability 

 to survive seed dormancy and germination under normal conditions. The effect of chemical treatment on 

 viability is most frequently in terms of a percentage increase in number of organisms (as seeds or 

 spores, e. g. ) growing or persisting when treated, though it might conceivably be in terms of increase 

 in duration of survival time. For example, chemically treated seeds might germinate in a higher pro- 

 portion or they might withstand storage longer without losing viability. 



An organism's viability might conceivably be regarded as analogous to that of surviving a path- 

 ology in that low viability which is responsive to treatment can be reasoned to be due to some detri- 

 mental environmental factor (etiological to a pathological state) which chemical treatment can affect. 

 Nevertheless, it has seemed more reasonable to circumvent the technicality of a somewhat artificial 

 association of pathology with "viability" by coding in Field E the organism treated with the test 

 compound and coding Field T-2 with the term viability which, in the restricted sense defined in the 

 Code, implies only the organism's ability to survive under normal conditions . When the organism is 

 described as exposed to some specific, named factor which proves lethal to the organism when unpro- 

 tected by treatment with the test compound (even one of the normal environmental factors such as heat, 

 cold, radiation, drying, moisture, low O2, etc., in excess ), its ability to survive should not be coded 

 by Symbol 12, but the pathology associated with the specified detrimental factor should be coded in 

 Field E and the effect of the test compound on the death of the organism due to the specific detrimental 

 factor should be coded by Symbol 1621, 1631, 1753, or 1754. If the effect of the test compound is 

 preventive of the pathology rather than effecting death due to the pathology , use a symbol of the 178- 

 series. 



10. Symbols 131 and 132; coding of REDUCTION OF INFESTATIONS BY ARTHROPODA due to test 

 compounds 



Tests in which application of the test compound is made to an infestation of arthropods on their 

 living host presented such a consistent coding problem that finally a special series of symbols has 

 been provided for coding the data. The special aspects of these tests which made the results seem 

 unsuitable for being coded with symbols of the 11--, 17--, or 18-- series will be reviewed briefly. 



First, the test compound's reduction of the arthropods is frequently not actually known to be 

 due to death of the insects; especially in field tests, the reduction might have been the result of 

 repellent action. A second aspect is the fact that so little control is afforded by the method whereby 

 application is made to a population (infestation) of arthropods en masse that the data offer little 



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