FIELD O 

 Column 49 



being continuous and is coded by Symbol 2. A continuous administration is exemplified by the method 

 in which a regulated volume and concentration of test compound flows over a period of time into the 

 venous circulation through a syringe fixed (i. e. , by single application) in a vein. An administration 

 is also continuous when bacteria, fungi, animal larvae, etc. , are grown in or on a habitat or medium 

 which has been impregnated with, dipped in, or painted with the test compound. An application of the 

 test compound in a paste or ointment to plant or animal parts, when the concentration remains relatively 

 constant over a considerable period of time, may also be properly considered as continuous and coded 

 with Symbol 2 in Field O. 



5. Two or more frequencies of administration during a single test 



If the frequency of administration is varied during the period of a single test , there is posed the 

 problem of deciding which of these frequencies to code, since only one can be coded. It would be conven- 

 ient in such a case to have a series of columns for coding each frequency in sequence or at least a 

 symbol for Column 49 which would represent frequency variance. Lacking these, the coder must be 

 responsible for making the most intelligent choice relative to the specific situation, as in the similar 

 situation in Fields M and N when the dosage size varies in a single test (see the first paragraph, 

 Division 11, Specific Directions and Explanations, for Fields M and N). The legend of the series of 

 frequencies should be included in the written abstract portion of Field O. 



6. Persistence of residue data: definition; coding in Field U; coding in Field O 



The expression, "persistence of residue", is used to refer to the length of the period over which 

 a test compound, applied once to an environment or host, retains potency to produce a given specific 

 action on a test organism. To determine persistence of residue, a series of exposures of the test organ- 

 ism (i. e. , a series of tests) are made, separated by appropriate intervals, each being merely to determine 

 whether the test compound residue is still capable of producing the action on the newly- exposed test 

 organism after the period since the previous test. 



This persistence of potency of a residue is not itself a biological action of a test compound, but 

 is instead a specific characteristic of the chemical, related directly to, or representing, its physical 

 properties. (The CBCC has not devised a code for physical properties. Such a code would include this 

 duration of potency, a characteristic that would fall in the same category as "stability" of compounds, 

 "stability in the presence of light", "resistance to oxidation", "boiling point", etc. Such properties 

 are not recorded in Field T-2 as if they were specific actions nor is there any other special coding area 

 provided for them. ) 



The CBCC has nevertheless made exception for indicating this one property, persistence of 

 potency, inasmuch as its importance seems to justify it. From the data of tests demonstrating persist- 

 ence, the CBCC extracts the information about the biological action demonstrated by the first exposure 

 of the test organism to the test compound residue. (Data from only that first test are coded; information 

 on the effectiveness of the test compound upon any subsequent exposures of the test organism to the 

 same residue are not coded. ) However, the entire period of time over which the residue was shown to 

 be effective (i. e. , persistence of the residue) is recorded in Field U (Column 66) of the same code line 

 that records the data from the first exposure. When this information is recorded in Field U, Symbol * 

 is always coded in Column 66 to indicate that the coding of that field is not duration of action in a 

 single test, but is the period of persistence of a residue. 



In a test demonstrating the action of a residue of the test compound ( whether or not the test is 

 one of a series demonstrating persistence of the residue), the test organism is ordinarily exposed to 

 the concentration in the residue for a measurable period of time. Therefore, the administration is coded 

 in Field O as being continuous (Symbol 2) and the duration of this exposure is coded in Field P. The 

 time between the introduction of the test organism to the residue and the reading of the initial result is 

 coded in Field V. (See also Field U, Specific Directions and Explanations Division 4. ) 



7. Sequence of administration of test compound and secondary compound 



This second use of Field O is with Symbols 0, #, and * (IBM zone punches 0, 11, and 12). 

 (Since these symbols can be used independently of the symbols for frequency of administration of the 

 test compound [Symbols 1 through 9], the single column of Field O can contain both types of information. 

 In other words, any of Symbols 0, #, or * can be coded in Field O along with any of Symbols 1 through 9. ) 



97 



