FIELD U 

 Columns 65 and 66 



B. The CBCC, however, has made a special provision for recording this time period (though 

 not an evaluation based on the time period) over which a test compound has been demon- 

 strated to retain its ability to produce a given response: IN THE SAME CODE LINE 

 DESCRIBING AND EVALUATING THE FIRST TEST (OF THE SERIES DEMONSTRATING THE 

 PERSISTENCE OF ACTIVITY OF THE RESIDUE), THE PERSISTENCE OF ACTIVITY OF THE 

 RESIDUE (I. E. , THE PERIOD FROM THE TIME OF APPLICATION TO THE SUBSTRATE TO 

 THE TIME OF THE LAST TEST IN WHICH THE TEST COMPOUND PRODUCED A RESPONSE 

 IN A TEST ORGANISM) IS CODED IN FIELD U . Inasmuch as this value is essentially 

 accessory to the rest of the coded information of that code line and is never related to 

 the evaluation coded in Fields W, X, and Y, it is necessary to distinguish it from the 

 more conventional use of Field U (see Divisions 1, 2, and 3, above); this is accomplished 

 by coding the Symbol * (i. e. , the 12 zone punch) in Column 66 of Field U with the persis- 

 tence of activity of residue value. 



Since the persistence of activity of a residue is only accessory information, the code line 

 represents only the action of the test compound on the test organism, and for this reason 

 Field X can be used only to evaluate that test organism's response and is never used to 

 evaluate the test compound's persistence. Therefore, if the author compares the test 

 compound's persistence as a residue to a standard compound's persistence as a residue, 

 this comparison can never be coded but the information should be included in the written 

 abstract. An attempt should not be made to use Criterion 03 or 04 nor to code this standard 

 compound in Field D, since this would be interpreted as stating that the secondary compound 

 was a standard for the effect coded in Fields T- 1 and T-2 rather than a standard for persis- 

 tence of a residue. (See also Division 6 of the Specific Directions and Explanations for Field O. 



5. Coding of persistence of activity of a residue when the measure is in terms other than time 



Occasionally, the durability of a residue of a test compound may be tested by treating it 

 repeatedly with any of the physical factors to which it might normally be exposed. Thus, the residue 

 might be repeatedly rinsed with water (simulating exposure to rain, tide, spray, etc. ) or radiated 

 (simulating exposure to sunlight), etc. The results are subsequently expressed, not in terms of time, 

 but as the number of washings or the amount of light, etc. , necessary to reduce the chemical's activity. 

 Thus, such persistence of activity of a residue can not be coded in Field U, for lack of suitable code 

 expressions; nevertheless, Field U should be used for the purpose of recording these data by coding 

 the field with Symbol * only and explaining by the written abstract the test compound's endurance of 

 the treatment. 



6. Choice of scales and ranges for coding in Field U 



Appropriate selection of scales in Field U has already been specially discussed for coding 

 alterations in survival time (Division 2, above). 



For coding durations of action, time to specific action, time to death, and persistence of 

 activity of a residue (Divisions 1, 3, and 4, above) care should similarly be exercised in selecting 

 appropriate scales. The explanation of selection of scales for Field P (Division 1 of the Specific 

 Directions and Explanations section for Field P) applies equally to selection of scales in Field U and 

 reference should be made to that discussion. 



When a time value is given in terms of an indefinite range of values (e. g. , "the ability of the 

 test compound to cause a specific effect persisted for one to two months"), code an average value (in 

 the example given, 6 weeks). 



A Field U time value may be expressed only as a general range (e. g. , "the response lasts from 

 'X' to 'Y' hours"). In particular, the range, 24-48 hours seems so common that the question has 

 frequently arisen as to how to code it. It is recommended that it be coded by the symbol representing 

 >24 hours through 48 hours rather than to double code in Field U both the symbols for > 12 through 24 

 and >24 through 48. 



164 - 



