TOXICOLOGY AND APPLIED PHARMACOLOGY 19, 276-360 (1971)



### Study of Intra- and Interlaboratory Variability in the Results of Rabbit Eye and Skin Irritation Tests

CARROLS.WEIL ANDROBERT A. SCALA
Mellon Institute, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213,

and Esso Research and Engineering Company, Medical Research Division, Linden, 

### Nen, Jersqv07036
Received October 12, 1970 

### Studyof Intra- andInterlaboratory Variability in theResults of Rabbit EyeandSkinIrritation Tests. WEIL, 

### C.S.,andSCALA, 

### R.A. (1971).Toxicol. Appl. Pharmacol. 

### 19,276-360. Twenty-five laboratories

supplied datafor a joint studyofthevariability oftestresults.Eachlaboratorywastotestskin andeyeirritation byareference andbyanonreference

methodfor eachof 12materials.
Thereliability andreproducibility ofexperimental findingsaresub.ject totheinfluenceof theparticular procedureemployedin conducting thetestaswellasto variability among thescientists

who interpret the results.Many laboratories oftoxicology haveattained a degreeof internal consistencythrough theuseoftheir own uniqueexperimental designs. There is little information on the consistency of resultsamong laboratories, eachof which hasuseditsown design.Most ofthe available data referto the acuteoral test. A fundamental question is whether these individualized procedures are more or less reliable in the measurementof effect than an arbitrary or reference procedure. The promulgation of suchfixed methodsby government regulatory agencies implies that reliability and reproducibility are attained only by standardization. This assumption
wastestedfor the acuteoral testin acooperative study reported by Weil and Wright (1967).They found noneedfor suchstandardtechniquesandconcludedthat competent laboratories will generally bein good agreementeventhough methodsmayvary. Since Draize’s initial publication (Draize et al., 1944)of methodsfor studying skin and mucousmembraneirritants, there havebeenmanyreports of methodsfor eyeand skin testing; interpretations ofthe resultsof suchtests;interspecies comparisons;and, for eye irritants, aseriesof color platesto aidin gradingresponses. A selected

bibliography of suchpapersaccompaniesthis study. Among the criteria for inclusion were reports of methodology in man or experimental animalsandthe resultsof studieson cosmeticproductsandtopical drugs.Specifically excludedwerestudiesonsensitization, clinical casereports, and screeningstudiesof industrial chemicals. No publishedreport hasbeenfound which contains data on eyeand skinirritation from referencematerialsusingreferenceandnonreferenceprocedures.A collaborative program wassetupto examinethesevariablesinasizablenumberofestablishedlaboratories; the presentreport describestheresultsof theseinter- andintralaboratory comparisons. 276INTERLABORATORY EYE AND SKIN COMPARISONS 

### 277

METHODS After apreliminary survey of potentially interestedinvestigators,it wasagreedto test eyeand skinirritation by a referenceand anonreferencemethod, the latter beingthe methodcommonly usedin eachindividual laboratory. Invitations weresentto over50 laboratories in the United States,Canada,and England to join in the program. This original list included governmental, consulting, food, chemical, cosmetics, and toiletries laboratories known to conduct eyeandskinirritation testingonexperimental animals.Thirty-one laboratories acceptedand25provided data in at leastaportion of the program. Theparticipating laboratoriesarelistedinTable 1alongwith atabulation by laboratory type showingto which phaseof the collaborative program eachcontributed data. The listing in Table 1isalphabetical. However, eachlaboratory wasranTABLE 1 LABORATORIES THAT PARTICIPATED IN THE COLLABORATIVE EYE AND SKIN IRRITATION TEST PROGRAM 

### Type” Laboratory
C I I T T T G T I I G C I C C C C C C T I G T T C AME, Inc.

AmericanCyanamidCompany Atlas ChemicalIndustries,Inc. AppliedBiologicalSciences Laboratories,Inc. Avon Products,Inc. Bristol-Myers Products Bureauof OccupationalSafetyandHealth, DHEW, PHS Colgate-Palmolive

Company TheDow Chemical

Company Eastman Kodak Company Food andDrug Directorate, DNHW, Canada Food andDrug Research Laboratories,Inc. GeneralFoodsCorporation Gulf SouthResearch

Institute HazletonLaboratories,Inc. Hill Top Research,

Inc. HuntingdonResearch

Centre,England IndustrialBio-TestLaboratories,Inc. International Research

andDevelopmentCorporation LeverBrothersCompany Mellon Institute; Carnegie-MellonUniversity Pesticides

RegulationDivision, USDA, ARC The Procter& GambleCompany Revlon Research

Center,Inc. WARF Institute, Inc. Eye test

NonReference reference Skin test

NonReference reference nSymbol Type oflaboratory method method method method C Consultant 9 6 8 6 I Food or industrial chemical 6 5 6 6 T Toilet goods and cosmetics I 5 5 5 G Governmental 2 1 3 2 24 li 22 19

### 278 WEIL AND SCALA



### domly assigned

acodenumberwhich hasbeenusedin thetabulation anddiscussion of the data. An adhocSteeringCommittee’ preparedthereferencemethodsfor eyeandskintesting.Thelaboratories wereurgedto follow preciselytheprocedures.Practical considerations precluded any attempt to control the sourceof the experimental animals.
A. ReferenceMethodfor Eye Irritation Test Animals. Six malealbino rabbits in good health, weighing at least2.0kg each,were usedfor eachmaterial. The eyeswerefree of defectsand irritation, and 24hr prior to application oftestmaterialtheeyeswerestainedwith anaqueous57;solution ofsodium fluorescein. The stain was allowed to contact the eyesfor 20 set and wasflushed thoroughly with distilled water at room temperature, The eyeswerethen examinedfor possiblecornea1

lesionsnot otherwisevisible. Three left and 3right eyeswereusedfor eachsample.Theanimalswerehousedsinglyandfreeof anyextraneousmaterial which might causeirritation. Application. Thelower lid waspulledawayfrom theeyeto form acupinto which 0.1 ml of materialwasinstilled. Thelid washeldopenfor afewseconds, then raisedto close with the upper lid. The 2 lids wereheld gently together for a few secondsbefore the animal wasreleased.The eyeswerenot washedfollowing instillation. Scoringanderaluation. Theeyeswereexaminedandthe degreeof irritation recorded at 1,24, and 72hr and 7 days after application of the sample.Observations on any animalwerediscontinuedafter24or 72hr if the eyes werefreeof irritation. Fluorescein stainingwasdoneat 24and72hr and7daysontheeyesof animalsnot previously negative. The grading of eye irritation wasaccording to the scaleof Draize et al. (1944). Injuries suchaspannus, keratoconus, and sloughing of cornea1epithelium were not included in the Draize systemandwererecorded separately.The scalefor scoring irritation and a data sheetfor onesampleare included in the appendix.
B. ReferenceMethod,for Skin Irritation Test Animals. Eight malealbino rabbits in good health and weighingat least2.0kg each
wereusedfor eachgroup of 4materials. Immediately prior to applying the materials the hair wasremoved from the backsofthe animalswith electric clippersin suchaway asto avoid abrasions.Theclipped areawaswideenoughto accommodate4gauzepads without overlapping. The animalswereplacedinrestraint atthetime thematerialswere applied and they remainedimmobilized during the 24-hr exposureperiod. Application. Four gauzepatches,each 1”x 1” cut from nonsterile, 12-ply material,
werefixed to the application siteson eachanimal by meansof l/2-inch adhesivetape applied in the shapeof an X. The testmaterial wasapplied by injecting 0.5 ml from a syringeandneedleinto theestimatedcenterofthegauzepad. Uniform contact ofsample with skinwasensuredby pressingthe padfirmly againsttheskinwith thethumb. Four materialswereappliedto theintact skinof 8rabbits according to thefollowing scheme, which permits variation of actual sites:

Rabbitnumbers 1,2 3,4 56 7,8 

### Compounds 12 21 34 43 34 43 12 21 ’ The membership of the Steering Committee was Steven Carson, Kenneth J. Olson, Donaid L. Opdyke, Robert A. Scala, Fred H. Snyder, and Carrol S. Weil.INTERLABORATORY EYE AND SKIN COMPARISONS 279



### Thus compound 1wasin position 1for rabbits 1and2,in position 2for rabbits 3and4, etc. The trunk of eachrabbit waswrappedwith an impervious Saranfilm suppliedby the Dow ChemicalCompany and heldin placelongitudinally with tape. The covering
waslooseenoughto permit insertion of 4fingersofthe hand horizontally betweenthe cuff and the animal. The endsof the covering wereleft open. Scot-&q and evaluation. 

### Twenty-four hr after application the patcheswereremoved, and30minlatertheskinsites examined.Theexamination wasrepeated48hrlater (72hr after application). Scoring of the reactions wasbasedon the amount of erythema, edema, and necrosis found. Necrosis was defined in this instance as “chemical denaturation of tissuesufficiently severeto result in fibrotic replacement(scartissue). Superficial escharwhich heals without scarisnot classifiedasnecrosis.”The skin reaction scores

of eachanimalineachcategory at24and72hr after application wereadded. The total scorefor all 8rabbitswasdivided by 16to yield aPrimary Irritation (PI) score for agivenmaterial. The scoringscale andasample

scoresheet

areinthe appendix.

C. Nonreference Methods 

### Eachlaboratory wasalsoaskedto testthematerialsaccordingto theproceduresthey usedroutinely for eyeandskinirritation. In reporting thosedata, thelaboratories were requested

to provide information onspecies andstrainof animal,sex,ageand/or weight range,method of application, scaleof irritation response,scoreassigned to any given response,

andany other pertinent data. Samples testedby thesenonreferencemethods
were to be ranked by the laboratory on the basisof their irritation with the most irritating given arank of 1,the next mostirritating arank of 2,etc. A similarranking
wasto bemadebyeachlaboratory for eyeandskindatausingthereferencemethods.

D. Statistical Procedures 

### Generally, nonparametric procedures were usedfor inter- or intralaboratory (or between-sample)

comparisons.Median scores for eyeinjury or primary irritation scores for skinirritation wereranked, usually assigningarank of 1for the mostsevere,2 for the next most severe,

. . . and N for the leastseverereaction. Theseranks were then summed for eachlaboratory (or for eachsample).The significanceofthesums of ranks
wascompared to the limits calculated by the method presentedby Thompson and Willke (1963). In therepeattestsin 2laboratories, theresultsofthe2techniciansin eachlaboratory
werecomparedbythesignedrank sumtest(Wilcoxon etal., 

### 1963).TheSpearmanrank correlation coefficient was usedto intercompare results of the reference and nonreferenceprocedures(Snedecorand Cochran, 1967).

E. Mater& 

### Initially 12materials,primarily constituentsof cosmetics, wereselected

for inclusion in the study. As the collaborative testingprogressed,it wasclearthat somematerials
were completely nonirritating. This lack of irritancy would reduce the power of the collaborative testto discriminatebetweenmethodsor laboratoriesonthebasis of irritation scores.

Therefore, 4of theoriginal materialsweredropped and4industrial chemicalsof pretestedirritancy wereaddedto the program. Each test material wasfrom a

### 280 WEIL AND SCALA



### single lot, and aliquots were repacked and shipped under code from asingle point to all participants. The materials used and the identifying code are listed in Table 2. Samples B, C, D, and H were later dropped as nonreactive and replaced by Samples M, N, 0, and P. The identification of the samples was not available to the participants.

TABLE 2

MATERIALS USED IN COLLABORATIVE EYE AND SKIN IRRITATION TESTS



### Code Material

A B C D E F G H I J K L M N 0 P 

### Ethanol,95“/‘, Propyleneglycol Formaldehyde,27: Glycerin Isopropylmyristate Triethanolaminelaurylsulfate, 467;aqueous Creamperoxide,20volume Aluminum chlorhydroxide, 50 %aqueous Triethanolamine Ethoxylated lauryl alcohol Decaethoxyoleylether Linoleicdiethanolamide n-Butyl alcohol Methyl ethyl ketone Methyl isobutylketone Ethyleneglycolmonoethylether

RESULTS

A. Low-Differentiating Materials It wasnoted, whentheresultsfrom thefirst group of laboratories hadbeenreceived, that somematerialshadaconsistently low order of eyeand/or skinirritation reaction. Thislack of irritation wasnot surprising,onreconsideration, asthe initial 12materials
werechosen,asstatedbefore,to betypical ofthoseusedbythecosmeticortoilet-goods industries.The datafrom alllaboratories tendedto agreeonthese,andtheir inclusion in the correlations resulted in significant correlations that often disappearedif their resultswereremoved (Tables56and57,for example).At first theresultsof B, C, D, and H wereremoved. Later E, I, and0 for theeyeaswell asA and Pfor the skintestswere deleted.Thelatter 3for theeyetestor 2for theskintestarethecompoundsstill included inthe9uer.sus

12materialsfor theeyetestandthe 10versus12materialsfor theskintest compared in Tables56 and 57; the resultswill be discussed in Section E. The eyeandskin reactionson thereferencetests,found in eachlaboratory for these low-differentiating materials, arepresentedin Table 62.Theseprimarily negative data
werenot includedinthemajority ofthesucceeding comparisonsanddiscussions.TABLE 3

EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH 95 “,I ETHANOL (MATERIAL A)

24 Hr-rabbit number

- 72 Hr-rabbit number 7 Days-rabbit number Median Laboratory No. 1 2 3 45 6 12 3 4 5 6 I

--__ 

### - --___ - __--- 63 25 65 8 51 25 65 6 47 49 59 4 66 19 9 19 55 57 38 4 10 26 28 24 40 50 50 14 48 16 21 38 17 29 39 15 59 20 13 8 37 35 37 36 19 11 41 15 25 32 20 18 33 23 4 24 55 45 30 9 14 14 40 18 35 37 15 7 37 17 4 4 37 37 37 0 6 30 4 0 19 33 35 2 16 9 9 4 23 15 23 11 19 8 17 2 28 5 0 35.5 10 31 0 0 28 15 22 12 2 39 23 9 13 17 21 39 43 41 0 63 19 19 36 2 9 22 15 38 9 16 15 0 9 9 9 5 23 13 2 8 9 7 13 6 100 4 40 7 2 2 26 7 17 21 8 22 2 4 4 6 9 43 43 6 6 16 0 11 64 2 0 0 2 2 0 10 0 6 2 0 0 2 0 029 0 0 4 0 0 49 29 38 59 41 1 23 49 41 4 32 30 62 14 40 58 38 12 39 44 39 25 39 35 35 9 37 35 30 31 25 26 30 22 13 35 15 13 0 12 2 23 15 18 28 16 19 21 25 18 22 22 19 I1 19 11 27 24 15 17 21 7 2 11 15 10 33 18 22 27 20 15 18 2 26 4 4 5 27 8 8 21 9 9 II 30 4 6 6 19 12 4 4 8 5 4 0 61 2 57 2 24 2 38 0 59 6 9 4 13 15 7 0 9 0 50 0 31 4 17 2 0 0 2 0 59 53 110 0 7 0 2 4 14 0 2 2 7 0 0 0 0 0 0 0 2 3 4 5 6 24 Hr 72 Hr 7 Days

-.~~~ ~__ ~- ~..____ 10 I1 30 2 32 50 38 10.5 57 0 0 0 29 48 19 1 0 4 5 0 2 46.5 24 2 12 0 0 0 22 45 29.5 0 21 6 6 2 13 39 17.5 6 2 2 9 7 2 36 17 3 5 10 0 29 0 31 20.5 7.5 0 0 0 0 0 30 14 0 44 0 0 2 0 25 8 0 4 2 2 0 74 24.5 5 2 4 4 0 2 4 23.5 9 4 2 2 4 0 6 22 14 2 0 2.5 0 0 0 20.5 5 0 0 4 12 2 2 20.5 10.5 2 57 59 0 57 57 17 42 57 0 35 16 33 110 17 18.5 24.5 0 5 5 5 5 17 9 5 0 0 0 2 0 16.5 7.5 0 0 0 49 0 0 15 7 0 0 2 4 4 0 12.5 4 2 0 0 5 10 5 10 6.5 2.5 0 0 0 0 0 5 0 0 0 0 0 0 0 5 0 0 0 0 0 9 0 2 0 0

- __-~- ______- --___ Median of laboratory medians 21.2 9.8 2TABLE 4 td

EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH 46 :,I AQUEOUS TRIETHANOLAMINE LAURYL SULFATE iz (MATERIAL F)

24 Hr-rabbit number 72 Hr-rabbit number 7 Days-rabbit number Laboratory ~ ~~ -~ -~ - ~ .~--- .___ ~_____ ~ -~~- No. 12 3 4 5 6 12 3 4 5 61 2 3 4 56

-~ __.~~~ 21 76 76 80 78 76 74 53 61 21 21 4 70 58 46 54 94 94 62 79 39 46 29 58 65 65 70 63 61 52 57 66 62 14 60 60 58 58 60 60 56 48 58 56 10 42 40 51 51 48 57 35 16 31 26 2 25 54 52 40 48 50 9 50 57 45 7 42 42 46 50 48 50 32 36 51 55 1 57 45 35 55 47 45 47 41 55 43 12 30 41 46 43 59 43 20 66 39 57 22 41 39 30 32 37 34 37 35 35 35 23 33 24 33 29 35 35 12 12 22 24 9 26 32 34 30 34 30 22 32 41 20 31 26 33 28 35 33 28 46 43 28 33 25 23 29 35 27 26 31 11 6 24 13 11 28 25 26 11 33 37 30 11 11 15 27 24 24 14 19 24 24 24 24 9 14 5 19 22 27 31 6 26 2 6 6 29 18 18 21 20 16 17 17 25 23 17 4 16 8 18 14 14 18 18 0 20 16 6 19 15 15 19 19 17 15 15 13 19 17 13 37 12 12 39 18 2 28 2 2 24 24 11 8 31 37 19 12 33 35 31 35 30 17 15 I5 12 19 15 22 33 37 20 8 9 9 8 18 18 11 2 2 20 45 28 66 5 0 0 14 10 24 101 54 2 73 27 9 99 42 54 51 59 28 45 28 24 22 34 56 56 19 36 56 0 54 24 28 33 4 9 4 5 24 18 47 0 16 4 36 0 29 22 51 5 34 36 55 2 7 47 45 27 2 55 39 0 0 59 59 46 82 35 18 55 82 35 30 22 22 28 33 2 12 53 24 0 0 5 7 100 9 22 27 0 59 35 0 2 0 30 30 46 18 11 28 30 30 15 21 0 2 0 2 33 41 37 41 31 2 7 7 55 41 19 14 24 15 4 0 0 0 2 22 0 2 4 31 0 6 14 15 15 42 2 0 33 2 61 110 0 16 4 2 68 41 10 15 8 8 10 15 8 6 48 452 6 0 2 14 2 35 23 55 27 19 28 30 18 22 30 13 39 20 4 6 2 10 30 0 0 16 65 0 4 76 41 7.5 64 58 34.5 64 55.5 28 60 56 45 49.5 27 7 49 46 10 47 43.5 20.5 e 46 46 14.5 B 43 58 50.5 35.5 35 22 % 33 23 6 31 24.5 1 E 30.5 31.5 24 F 28 14 2 27 22.5 19 24 16.5 2 24 6 3 17.5 16 8.5 16 18 10 16 15 8 15.5 14 4 15.5 34 27.5 15 26 9.5 10 15 7

Median of laboratory medians 30.8 26.5 Median

24 Hr 72 Hr 7 Days

9.8

### TABLE 5

EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH 

### 20-VOLUME CREAM PEROXIDE (MATERIAL 

### G)

24 Hr-rabbit number 72Hr--rabbit number 7Days-rabbit number

3 4 5 61234561234 5 

### Median

_.~ ~~ ~-- 6 24 

### Hr 72Hr 7Days No.

- 29 90 63 88 90 79 8 84 86 

### 55 86 82 

### 1 82 86 62 86 55 25 68 79 78 86 90 16 17 79 81 8 85 7 70 70 70 72 40 12 66 64 84 

### 11 90 9 

### 55 61 57 59 59 21 52 56 56 56 54 18 54 69 61.5 54 34 

### 10 59 59 39 43 39 24 41 63 59 35 35 19 48 50 48 70 33 

### 11 37 45 41 

### 51 71 

### 14 56 60 36 56 26 23 

### 11 22 

### 0 53 61 13 57 48 6 

### 0 46 22 21 37 4 55 17 31 51 13 23 53 31 27 21 31 31 66 2 5 26 29 29 26 17 4 

### 0 6 23 23 23 30 30 

### 11 11 11 2 2 

### 0 11 4 23 6 

### _-- .-~ ~-__-~
37 90 38 86 86 80 14 65 24 78 82 82 78 84 47 84 60 86 78 69 37 82 82 78 71 62 84 55 82 2 2 72 72 92 84 4 29 64 68 68 22 2 

### 0 44 

### 110 6 47 49 4 65 45 4 12 43 

### 0 72 64 84 82 92 38 92 82 84 87 97 22 82 14 80 

### 0 84 2 80 7 78 

### 0 12 53 59 53 53 55 12 5 9 7 5 22 42 68 53 70 72 6 49 49 49 49 17 6.5 12.5 15 4.5 2.5 

### 0 24 

### 0 33 8 59 47 37 18 32 31 33 9 31 7 24 57 37 55 55 

### 51 35 53 53 41 

### 51 53 48 48 48 46 

### 50 26 46 42 42 42 42 47 73 71 71 75 75 77 65 67 67 32 26 54 76 34 54 7 46 54 78 12 54 51 

### 0 0 0 45 55 47 2 6 

### 0 45 26 44 22 

### 0 0 42 55 

### 0 4 

### 0 0 7919 9 2 20 

### 0 77 12 5 2 20 26 28 4 18 23 23 19 23 

### 0 6 23 

### 11 29 64 64 64 

### 0 4 

### 10 65 60 60 26 

### 11 37 25 4 11 24 2 21 26 2 25 

### 0 2 21 14 19 16 

### 0 0 17 

### 10 9 12 19 7 4 4 9 17 63 7 2 80504090000 41 0 83.5 83 41 102 83 81 2 72 82 74.5 44 22 82 66 70 

### 1I 80 46 2 97 70 83 60 2 65 47 

### 11 0 58 53 

### 0 0 55 60.5 6 II 54 5.5 19 28 51 32.5 53 53 49 52 20 42 48 47 65 71 46 74 

### 0 44 46 50 27 40 41 45 

### 0 86 36 32 

### 0 58 29 14 15 15 28.5 23 

### 0 0 26 46.5 

### 11 16 26 17.5 15 0 23 15 6 2 11 8 

### 0 0 7 2



### _~~-- -.-

53 

# 2

73.5 37 

# g

22 

# F

11.5 

# $

85.5 

# 5

33.5 

# 8
6 

# 4

49 9.5 

# 2

21.5 53 

# 5

42 

# 74

66 

# 2

49 

# 8
11 5 0 % 8.5
15 

# g

35 

# z

13.5 5 6.5 

### 0

Median of laboratory medians 48.5 46.8 21.8 b2 wTABLE 6 bi EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH P

ETHOXYLATED LAURYL ALCOHOL (MATERIAL J)

Laboratory

__ No. 1

21 59 14 60 4 24 29 41 12 41 2 55 23 38 1 32 10 55 9 30 22 28 31 29 11 31 5 20 8 47 19 43 24 8 25 10 16 21 30 16 7 11 18 2 27 26 13 30 24 Hr-rabbit number 72 Hr-rabbit number

- -__ ~ _. 2 3 4 5 6 12 3 4 5 61 7 Days-rabbit number

-~
____ - 2 3 4 5 6

49 81 83 79 79 30 14 31 36 35 24 5 2 4 5 5 5 58 56 60 58 58 58 36 29 60 58 58 24 4 2 58 29 46 53 57 57 9 51 21 57 77 7 21 5 7 83 85 5 5 36 28 43 71 67 5: 34 32 43 88 108 35 6 9 47 73 88 39 59 41 43 41 33 37 59 59 59 33 22 7 26 55 41 38 4 28 28 52 57 42 0 37 15 100 79 10 0 9 0 35 43 39 39 41 35 35 57 20 43 11 14 37 46 2 41 5 0 5 35 23 48 40 35 23 24 19 29 17 28 2 0 0 0 0 2 26 30 33 35 41 37 24 32 48 20 57 39 7 20 38 7 28 0 34 32 43 37 7 0 26 19 61 43 0 0 21 4 61 31 28 6 33 37 35 33 53 0 35 62 31 22 37 0 33 22 20 26 28 31 33 19 53 74 38 73 33 5 38 38 26 28 18 0 24 28 2 37 28 29 28 41 65 51 34 7 53 66 81 49 37 25 25 27 27 31 18 37 20 29 22 33 9 32 20 36 24 36 45 15 35 2 4 45 11 10 25 11 37 6 4 0 21 0 45 11 43 33 14 9 28 9 43 21 9 5 10 9 14 9 5 0 19 33 37 17 28 35 43 49 61 46 34 33 35 45 86 35 48 21 23 36 15 21 39 43 45 6 4 2 39 37 61 0 2 2 19 23 19 19 17 13 15 19 7 4 23 4 4 0 0 0 16 16 11 13 13 8 32 31 37 41 26 35 54 69 67 49 38 43 11 26 16 14 11 9 11 9 9 14 11 7 4 2 9 7 2 11 11 11 7 13 5 18 18 9 0 23 0 25 25 0 0 25 19 2 17 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12 0 2 4 10 37 37 0 59 63 63 2 0 0 53 48 73 Median

24Hr 72 Hr 7Days

79 30.5 5 58 58 26.5 52 21 6 42 47 41 41 48 24.5 40 49.5 9.5
38.5 28.5 5 35 23.5 2 P 34 34.5 2: 33 32.5 12.5 % 30.5 34 22 28.5 45.5 z

27 28 37.5 c

51 * 26 25.5 28 25 18 5 23.5 15 9 23.5 42 40 21 22.5 19.5 19 14 2 13 36 51.5 12.5 10 5.5 11 13.5 12.5 9.5 0 0 7 48 25

Median of laboratory medians 28.2 29.5 16.0TABLE 7

EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH DECAETHCIXY OLEYL ETHER (MATERIAL K)

24-Hr-rabbit number Laboratory -___ 72-Hr-rabbit number

NO. 12 3 4 5 6 12 3 4 5 6 1

4 29 12 19 14 31 5 16 22 9 24 7 1 10 30 2 13 21 23 11 25 18 8 27 63 99 59 81 79 79 41 0 30 99 37 0 15 41 43 41 14 37 36 63 60 30 8 14 90 49 19 14 63 39 29 45 21 8 10 48 19 70 16 26 43 55 19 17 38 13 24 36 17 8 15 0 28 18 30 62 26 50 18 11 21 60 14 36 0 52 52 8 13 28 28 42 37 12 4 37 52 18 24 18 22 22 26 20 43 39 24 43 41 43 40 30 23 21 21 18 19 19 3.5 26 35 20 70 2 10 10 35 32 35 10 13 2 6 28 60 4 2 21 28 17 10 37 19 17 36 4 8 33 21 0 21 15 13 6 23 17 45 45 43 12 41 41 30 13 13 16 18 11 30 11 13 1: 16 11 16 13 10 13 15 37 15 11 8 11 6 30 13 4 29 42 8 13 13 11 17 22 9 5 22 13 13 13 17 10 13 17 2: 16 3: 1: 6 8 12 15 13 49 4 63 26 17 11 29 9 14 12 14 0 6 12 12 8 12 0 6 2 0 0 12 12 12 10 12 12 4 6 8 4 6 14 9 8 41 22 10 14 10 6 26 6 12 4 10 2 32 6 39 6 10 6 74 6 55 4 10 4 68 6 6 39 8 4 13 0 4 33 17 6 85 2 45 5 8 6 6 12 13 13 28 22 13 10 6 2 6 11 2 6 2 9 56 4 35 8 14 25 4 4 4 4 4 4 5 4 4 4 4 4 0 7 Days-rabbit number Median

105 34 30 30 105 79 39 47 2 0 6 90 39 45 6 8 108 8 110 34 20 24 22 IO 0 8 32 16 4 4 36 2 19 29 19.5 40 4 0 42 42 28 37 55 28 34 43 53 22 42 70 4 63 110 12 21 30.5 0 0 53 55 0 21 9.5 43 2 4 41 6 20 19 41 61 0 0 39 16 42 9 9 14 11 7 14.5 14.5 0 0 0 35 0 14 11 2 2 5 0 0 13 8.5 35 43 23 23 8 13 17.5 II 13 11 4 0 12.5 21.5 2 0 2 2 0 12 5 0 0 0 0 0 12 6 7 4 2 0 0 12 8 4 35 0 2 2 8 8 2 31 2 2 77 7 11.5 6 29 9 9 12 6 13 100 0 0 0 0 4 11.5 0 2 0 0 0 4 4

-- ~~~. 

### - -. 7 Days

32 a 26.5 2 12 9 E
4 $
29 F 41.5 8 37.5 5 1 z m 5 40 10 5
0 i% 2 I? 23 11 8
1 9 0 E
2 z! 3 CA

2 9 0 0

Median of laboratory medians 14.2 15.2 7.0 w

### 286 WEIL AND SCALA

W

m

dTABLE 9

EC EYE-MEDIANS AND SCORESOF INDIVIDUAL RABBITSTREATED WITH IPBCJTYLALCOHOL(MATERIAL M)

24-Hr-rabbit number 72 Hr-rabbit number 7 Days-rabbit number Laboratory ~ ~~___ ~ ____- ._~___. ~~ No. 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 24Hr 72 Hr 7 Days

4 37 77 77 75 83 83 38 38 53 31 31 7 28 37 11 26 4 0 77 34.5 18.5 14 50 60 60 58 52 58 38 42 48 56 58 58 24 19 19 54 44 27 59 52 25.5 31 57 47 9 72 55 55 63 14 4 72 35 30 53 0 0 42 5 0 55 32.5 2.5 2 80 92 4 45 43 57 15 36 4 2 90 82 20 0 0 0 88 9 51 25.5 4.5 10 55 43 6 45 57 59 53 44 4 14 44 47 20 14 - 5 7 20 50 44 14 12 46 46 46 46 39 34 44 66 44 66 35 42 6 8 8 42 55 28 46 44 17 11 35 32 35 35 37 35 31 28 39 4 59 11 2 24 2 0 29 2 35 29.5 2 25 37 33 35 33 35 33 8 33 29 33 28 31 2 26 2 2 2 0 34 30 2 22 37 32 39 32 0 35 35 28 57 30 0 35 2 0 5 6 0 0 33.5 32.5 1 9 32 33 37 35 33 30 15 20 35 16 33 9 5 35 45 0 29 0 33 18 17 29 34 36 32 37 32 30 26 28 26 33 31 24 17 17 17 9.5 0 2 33 27 13 1 45 28 23 28 33 33 60 23 16 14 21 19 24 2 0 0 7 0 30.5 20 1 23 39 29 31 27 26 31 11 5 7 0 0 0 2 0 0 0 0 0 30 2.5 0 27 24 2 24 29 2 28 7 2 29 22 2 4 0 0 0 0 0 0 24 5.5 0 5 25 22 17 22 22 22 20 17 13 16 15 6 7 2 2 2 18 0 22 15.5 2 24 23 21 21 21 19 6 33 31 37 33 33 0 2 2 0 2 0 0 21 33 1 18 26 19 16 17 18 16 6 6 8 23.5 0 1 0 0 0 26 3 1 17.5 6 0.5 13 6 16 16 16 10 16 2 10 12 12 52 10 4 2 2 4 2 2 16 11 2 16 19 8 16 8 14 22 43 2 10 6 26 17 5 0 0 0 37 0 15 13.5 0 19 17 6 45 29 10 0 0 0 4 6 0 0 0 0 2 2 0 0 13.5 0 0 8 15 8 6 10 15 13 26 2 0 6 6 4 0 0 0 0 0 0 11.5 5 0 30 11 9 12 2 2 42 2 0 0 7 0 0 0 0 0 0 0 0 10 0 0 21 6 2 6 0 6 6 6 0 6 2 6 6 0 0 0 0 0 0 6 6 0 7 4 2 0 2 4 2 2 0 0 2 2 2 0 0 0 2 0 2 2 2 0 Median



### - Median of laboratory medians 30.2 19.0 1.5TABLE 10 z 00 EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH METHYL ETHYL KETONE (MATERIAL N)

24 Hr-rabbit number 72 Hr-rabbit number 7 Days-rabbit number Median Laboratory No. 12 3 4 5 6 12 3 4 5 6 12 3 4 5 6 24 Hr 72 Hr 7 Days

14 21 50 48 60 60 60 9 36 36 58 62 21 0 19 19 36 44 0 4 37 41 38 63 63 63 31 11 18 21 20 36 12 10 7 11 0 25 10 46 53 53 16 35 2 14 44 16 9 16 0 0 7 - 7 9 0 12 39 37 46 39 39 39 35 39 57 23 44 44 8 13 13 6 11 23 11 35 33 33 30 23 34 21 26 19 30 4 13 2 21 2 2 2 2 29 38 32 36 23 34 32 30 34 34 23 32 34 4 16 14 2 25 48 2 48 9 63 8 61 16 7 7 37 0 7 9 4 0 5 0 5 5 19 29 35 49 27 20 47 19 2 21 11 2 12 7 0 2 0 0 7 31 57 25 9 27 47 35 18 25 4 4 9 9 0 0 0 0 0 0 22 35 8 35 0 25 35 29 2 35 0 25 33 2 0 0 0 0 0 5 27 27 22 22 20 22 22 13 11 6 13 22 9 7 2 0 6 10 9 29 21 22 18 18 34 20 7 16 9 11 16 14 14 10 0 22 0 24 17 15 21 21 17 17 31 13 19 35 11 4 2 0 2 0 0 0 13 6 14 16 16 16 16 10 10 12 12 10 2 2 2 30 15 13 15 15 15 15 1; 31 19 33 13 8 2 0 2 4 2 2 0 0 2 1 8 18 11 11 11 6 2 2 0 7 2 2 0 0 0 0 0 0 23 9 11 11 29 34 10 0 0 0 12 7 0 0 0 0 2 0 0 25 6 13 8 35 4 13 2 35 2 11 2 4 2 0 0 2 2 0 8 10 4 4 10 20 25 0 0 0 4 15 4 0 0 0 0 0 0 16 8 8 23 8 10 10 2 0 21 4 6 2 0 0 0 0 0 0 21 15 6 10 6 6 6 10 10 12 12 6 6 0 0 0 0 0 0 18 4 12 8 2 6 4 0 0 6 0 2 10 2 0 0 6 1 7 2 2 0 2 0 2 0 2 0 0 0 2 0 0 0 0 0 0 27 2 31 4 2 2 2 0 26 2 0 2 0 0 33 0 0 0 0

--. 55 36 19 52 20.5 10.5 40.5 15 7 39 41.5 12 33 20 2 33 33 15 32 7 4.5 < 32 11.5 1 31 9 0 E
30 27 0 22 13 6.5 fs
21.5 16 12 z 17 16 0 t 16 10 2 15 18.5 1 11 2 0 11 0 0 10.5 3 1 10 2 0 9 3 0 6 10 0 5 0.5 0.5 2 0 0 2 1 0

Median of laboratory medians 19.2 10.8 0.8TABLE 11

EYE-MEDIANS AND SCORES OF INDIVIDUAL RABBITS TREATED WITH ETHYLENE GLYCOL MONOETHYL ETHER (MATERIAL P)

24 Hr-rabbit number 72 Hr-rabbit number Laboratory No. 12 3 4 5 6 12 3 4 5 6

- 4 61 59 63 63 26 26 51 26 14 43 11 7 I 18 47 40 45 64 45 4 35 29 21 41 16 12 39 46 46 44 46 39 25 39 35 35 64 35 14 34 38 26 52 46 46 26 14 19 36 46 34 29 34 21.5 27 36 36 6 4 2 21 22 38 4 22 10 30 20 30 35 32 10 28 13 30 35 30 11 34 26 2 29 6 33 2 35 2 17 4 4 23 27 37 18 27 22 30 17 6 5 0 7 15 31 25 30 25 27 37 9 13 4 13 27 45 0 5 22 17 25 17 29 31 13 6 I1 0 11 11 2 18 9 65 0 32 28 0 0 9 0 5 0 8 10 18 25 6 35 25 0 16 49 0 4 0 10 35 11 14 9 26 28 9 2 2 2 7 9 9 11 15 20 20 32 17 0 0 0 0 25 0 13 32 16 12 17 12 16 56 12 6 6 6 32 18 17 14 17 18 10 10 0 11 1: 4 19 8 4 25 33 15 13 10 37 15 9 15 4 2 16 14 12 12 16 10 4 12 12 12 12 6 2 19 11 11 11 6 13 11 0 0 5 0 9 0 24 11 10 8 10 15 17 0 33 8 2 24 32 27 18 4 7 11 10 21 2 2 2 2 0 2 21 4 4 8 0 0 6 0 0 0 0 0 0 30 2 2 0 4 2 2 0 0 0 0 0 0 7 2 0 0 2 2 0 2 0 0 2 2 0 7 Days-rabbit number

1 2 3 4 5

27 0 6 0 2 2 2 0 0 4 0 0 0 0 0 0 2 0 0 0 0 0 0 0 12 7 0 0 0 12 0 0 21 0 23 18 8 35 28 12 0 9 9 0 0 2 0 4 0 0 0 13 11 11 4 2 2 2 2 2 0 2 0 2 0 4 22 20 0 4 6 0 4 9 0 0 0 5 0 5 54 0 0 0 0 0 0 5 5 0 0 0 10 0 2 0 2 0 1 6 0 6 2 4 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

6 Median

__- 24Hr 72Hr 7 Days

60 20 3.5 2 45 25 0 2 45 35 20.5 42 30 4.5 F
30.5 12.5 1 $ 30 29 6.5 $
27.5 4 2 2 27 6.5 1 * 26 13 2 ? 23.5 11 4 in

23 0 0 21.5 2 0 $ 20 4.5 0 K 18.5 0 0 52 16 9 1 15.5 4 3 8
15 10 0 $ 12 12 0 z 11 0 0 0 10.5 16 0 5
10.5 2 0 4 0 0 2 0 0 1 1 0



### - Median of laboratory medians 20.8 7.8 0 haTABLE 12 MINIMUM-MAXIMUM SCOREFOREYESOF INDIVIDUALRABBITS-% HR REFERENCE PROCEDURE s

Laboratory - -~ - No.” A F G J

14 29 4 12 1 10 31 22 2 9 11 23 25 21 5 19 16 24 7 13 18 8 27 30 Any laboratory 38-58 58-60 26-60 56-60

25-65 58-70 37-90 28-71 3C62 46-94 O-25 9-57 17-44 30-59 1l-90 39-59 23-59 35-57 55-86 2348 9-33 40-57 39-59 26-55 25-55 26-35 13-53 19-33 13-37 30-41 4-79 637 4-100 25-54 &23 4-57 20-37 26-34 12-61 O-43 11-28 1l-37 37-71 2-37 15-35 24-35 &61 35-41 35-39 23-35 68-92 IO-36 9-43 74-80 22-56 49-83 8-27 631 17-29 20-3 1 o-12 15-19 33-70 9-43 15-25 8-18 8-l 10 17-23 13-21 8-37 35-63 8-37 2-36 42-50 40-72 11-26 o-37 2-39 o-57 O-30 o-28 1621 17-62 2-13 O-29 8-18 55-86 247 2-23 14-24 2-66 O-26 2-6 12-19 2-30 8-16

O-100 2-80 o-1 10 O-83 Material

K L

18-62 40-68 14-43 32-53 59-99 24-65 14-63 39-63 10-37 31-59 8-42 4&57 8-52 24-53 lo-35 29-39 449 44-63 lo-37 26-37 6-39 14-39 841 30-39 6-39 1l-37 10-12 32-76 18-26 20-24 17-55 22-53 18-30 19-25 6-23 19-34 1l-30 O-11 o-14 6-39 645 7-16 2-11 2-14 all 4 7-26 13-22 13-25

o-99 O-76 M N P



### - 52-60 21-60 2652 30-37 23-38 636 37-83 37-63 26-63 3446 3746 3946 23-45 6-18 18-64 6-59 2-53 9-35 9-72 9-57 9-37 o-39 o-35 10-35 4-92 8-61 O-65 30-37 18-34 11-32 32-37 23-34 2-34 26-39 9-34 18-37 33-37 4-35 10-37 o-6 6-15 O-8 17-25 2C27 17-31 o-45 20-49 6-l 3 8-22 8-23 4-16 6-23 15-21 8-17 o-4 o-2 o-2 6-16 6-16 12-32 16-26 2-12 10-18 6-15 4-25 6-35 2-29 2-31 4-21 2-42 13-15 O-4

O-83 O-63 O-65 

### - 

### Any material

18-68 6-90 o-99 1l-90 6-86 2-59 8-72 o-79 ,r O-100 F O-61 2-71 % O-61 4-92 8
O-83 $ 6-31 O-70 4-110 6-63 O-72 o-57 o-62 O-86 O-66 O-42

-

aLaboratories ordered by sum of ranks of 24-hr medians as in Table 26.INTERLABORATORY EYE AND SKIN COMPARISONS



### B. Eye Test-Reference Procedure 291

For quantitative comparisons, medians of the scores were calculated for the 6 rabbits treated and read for eye irritation. The scores at 24 hr, at 72 hr, and at 7 days for the individual rabbits as well as the medians of these totals for all 6 rabbits at each time period for materials A, F, G, J, K, L, M, N, and P are presented in Tables 3-l 1for the 24laboratories that participated in the reference eye test. The order, from top to bottom in each table, is inseverity of the median total score at 24hr. Thus in Table 3, Material A, the highest median score at 24 hr was 50 for laboratory 29, and the lowest was 2 for laboratory 8; the results of laboratory 29 were, therefore, presented first and those of laboratory 8 last.
TABLE 13

RANGEOF SCORESFOR EYESOF INDIVIDUAL RABBITS-24-HR REFERENCE PROCEDURE"
Range for material Laboratory No.~

_-~ - 14 29 4. 12 1 IO 31 22 2 9 11 23 25 21 5 19 16 24 7 13 18 8 27 30 20 2 34 4 44 28 8 39

40 12 53 43 29 21 7 15 32 48 25 48 44 41 46 26 27 29 79 20 49 24 12 9 36 22 31 25 27 28 22 12 24 17 20 29 34 17 53 52 30 9 40 14 44 29 63 48 24 11 75 31 25 10 39 35 96 29 23 53 45 19 88 53 17 8 49 43 27 11 7 16 17 26 34 35 33 25 5 11 20 11 61 6 33 9 13 25 4 12 24 26 33 26 4 31 34 6 34 34 2 44 6 9 19 25 12 11 8 4 8 7 12 4 37 34 38 31 45 29 10 10 102 6 12 6 14 15 8 29 28 29 17 15 17 6 34 8 32 15 19 11 4 2 37 37 57 30 14 33 10 10 28 5 45 II 39 9 10 10 29 10 31 45 9 12 9 21 21 10 64 26 0 19 27 29 4 7 28 8 9 12 40 2 J 

### -K L M __- N 

### ___. P

__~~~ 26 30 37 7 46 26 28 25 65 21 32 19 27 8 14 7 12 9 2 20 8 29 17 4

aMaximum minus the minimum (Table 12). bLaboratories ordered by sum of ranks of 24-hr medians asin Table 26.



### Variations amongthesetotal scores for individual rabbitsdiffered considerably inthe different laboratories. The maximum possiblescorefor eyeinjury is 110.At 24hr with materialA, Table3,therangeintotals for individual rabbits was4to 100inlaboratory 2 while atthe same

timeperiod it wasonly 35to 39in laboratory 25and 2to 6in laboratory 30.Similarly, the rangeof 2to 110wasrecordedat 72hr in laboratory 7(Table 3)

### 292 WEIL AND SCALA



### while a range of 0 to 2 was recorded in both laboratories 19and 30. It should be noted that the median for the 72-hr group in laboratory 7was 18.5, relatively unaffected by the maximum score of 110. The arithmetic mean for these 6scores would have been 31. The minimum and maximum scores for each material for each laboratory at the 24-hr reading period are recorded in Table 12. The overall minimums and maximums for each material are presented at the bottom of this table. The smallest range was 0 to 63, for material N. The largest range was 0to 110,the lowest and the highest possible scores, for material G. Some laboratories recorded low and very high scores, e.g., laboratory 2 had scores ranging from 0 to 100 and laboratory 16from 4 to 110. Other laboratories had much smaller ranges, e.g., laboratory 5had no score over 31 and laboratory 30 had
no score over 42.
TABLE 14

RANK AND SUM OF RANKS OF RANGES LISTED IN TABLE 

### 13

Rank of range for material Laboratory No.” A F G J K L M N P

14 15.5 24 13 24 4 6.5 17.5 4 9.5 29 2 10.5 7 4.5 12 1I 19.5 13.5 5 4 7 120 2 4 2 4 9 3 12 11 4 2 16 1 10 13 19.5 21 1 4 8 16.5 15 13.5 6.5 9 15 2 10 12.5 9 23 11.5 8 14 3 2 9.5 31 8 17 10 18 4 5 2 3 7 22 12.5 12.5 3 9 15 20 7 5 11 2 1 4 22 1 2 12.5 1 1 I 9 18.5 18.5 8 4.5 13.5 18.5 19.5 I2 12 11 18.5 6 13 6 10 9 22 16 4 23 15.5 12.5 5 22.5 10 21.5 I2 10 14 25 23.5 10.5 21 13.5 10 8 23.5 6 8 21 5.5 21 13 7.5 23 I 21 19.5 19.5 5 17 7 24 19.5 22 24 17.5 21 16 19 20 23 1I 7.5 7 4 5 7.5 22 16 21 15 1 22.5 19 23 11 13.5 17 24 22 4 18.5 11.5 17 15 10 22 18 7 5.5 18.5 15 17 16 18.5 23.5 23.5 24 13 3 2 6 10 18 3 14.5 17.5 13 18 10 22 9 19.5 6 21.5 14.5 17.5 19.5 8 9 15 16.5 3 20.5 16.5 16 11 6 27 14 I5 4 13.5 24 12.5 8 7.5 15 30 23.5 20 18.5 21 20.5 16.5 6 23.5 23 Sum of ranks

With Without G G

118 105 85 78 52 32b 97.5 95.5 89.5 73 92.5 69.5 74 64 95 92 45.5” 23.5’ 125 II7 104.5 91.5 123 118 124 103 131 118 168 144 107 96 143 142 138 119.5 161.5 146.5 87 81 139.5 130.5 113.5 97 113.5 109.5 172.5 154

aLaboratories ordered by sum of ranks of 24-hr medians as in Table 26. bOutside limits for 8 samples; c(,,.,,~ = 41.8 to 158.2. cOutside limits for 9 samples; c(,,.,,~ = 50.5 to 174.5.



### The ranges 

### arelistedin Table 13.They wereranked for eachmaterial from 1for the largestrangeto 24for thesmallest.Theseranksandtheir sums arepresentedinTable 14. For example,for material A, laboratory 2hadarangeof 96andwasgiven arank of 1, whilelaboratories25and30hadrangesof4; both weregivenranksof23.5. It wasnotedINTERLABORATORY EYE AND SKIN COMPARISONS 

### 293

that unusual results occurred with material G (20-volume cream peroxide). For example,otherthan for G, laboratory 4hadno rankshigherthan 9while the rank for G
was20. Similarly, laboratory 2 ranked 22for G while it ranked 1for 5other samples, and2and4for two others.Therefore, the ranksfor eachlaboratory weresummedwith and without that for material G. The ranks and sumsof ranks for the minimum or maximum scores

arepresented

in Tables15and 16.Again, therank of 1wasgivento the largestabsolutevalue for each,2to thenext largest,etc.A listispresentedinTable 17of the laboratories which had unusually low or high sumsof ranks. A low sumof ranks indicatesgenerally large rangesor high minimumsor maximums.

TABLE 15 RANK, AND SUM OF RANKS, OF MINIMUM SCORE FOR EYES OF ANY

RABBIT-24-HR REFERENCE PROCEDURE’


### Sumof ranks Rankfor sample Laboratory ___~- With Without No.* AFGJKLMNPG G

14 1 2.5 

### 10 1 3 2.5 1 5 2.5 28.5” 18.Y 29 4.5 2.5 6.5 5 6.5 5.5 6.5 3.5 16 56.5 50 4 3 4 22.5 13.5 1 11.5 2 1.5 2.5 61.5 39d 12 8 8.5 16 3 6.5 4 3 1.5 1 51.5 35.5d 1 6 7 2.5 7 11.5 7 9 16 4.5 70.5 68 10 14.5 6 5 6 15 2.5 15.5 21 12.5 98 93 31 4.5 10.5 14 9 15 11.5 12 11.5 12.5 100.5 86.5 22 11.5 8.5 18 17 11.5 9 22.5 23.5 10 131.5 113.5 2 17 12 22.5 18 21.5 1 18 13.5 22.5 146 123.5 9 7 10.5 15 23 11.5 10 6.5 8 8 99.5 84.5 11 13 19 6.5 20 18.5 17 5 3.5 20 122.5 116 23 9.5 13 22.5 4 15 8 8 11.5 4.5 96 73.5 25 2 14 1 12 18.5 19 4 18.5 10 99 98 21 14.5 1 11 2 11.5 5.5 22.5 16 22.5 106.5 95.5 5 I6 23 12.5 8 3 14 10 6.5 6 99 86.5 19 22.5 16 9 13.5 5 13 22.5 6.5 16 124 115 16 9.5 21 17 10 3 15.5 13 13.5 18.5 121 104 24 11.5 21 8 15.5 18.5 15.5 15.5 9 14 128.5 120.5 7 19 5 4 11 9 24 22.5 23.5 22.5 140.5 136.5 13 22.5 24 22.5 23 24 22 15.5 16 7 176.5’ 154 

### 18 22.5 15 12.5 20 18.5 20.5 11 21 10 151 138.5 

### 8 22.5 21 2.5 20 23 23 15.5 18.5 16 162 159.5d 27 19 17 19.5 23 21.5 20.5 19.5 21 18.5 179.5’ 160* 30 19 18 19.5 15.5 8 18 19.5 10 22.5 150 130.5 (1Minimum score from Table 12. bLaboratories ordered by sum of ranks of 24-hr medians asin Table 26. cOutside limits for 9 samples; ~~~~~= 50.5 to 174.5. *Outside limits for 8 samples; o(,,.,,~ = 41.8 to 158.2.



### Thosewith significantly low sums in 1or moreofthese3categorieswereIaboratories 2, 4, 12,and 14,while laboratory 29 had nearly significant minimum and maximum
sums. Oneofthese,laboratory 4,waslow inall 3categories;thuslaboratory 4displayed
atendencyto haveunusuallyhighranges andto havehighminimum andhighmaximum

### 294 WEIL AND SCALA



### scores for thereferenceeyetest.Three ofthelaboratories, 14,12,and29,hadfairly consistently high minimums and maximums while laboratory 2 had high rangesand maximums.

TABLE 16

RANK, AND SUM OF RANKS, OF MAXIMUM SCOREFORANY RABBIT24-HR REFERENCE PROCEDURE,EYES”

Rank for sample Laboratory

_ ~~~

~~~--~~ No.* A F G J K L M N P

14 5 4 16 3 3 2 4 3 4 29 2 3 3.5 2 8 9 13.5 8 9 4 3 1 23 5.5 1 3 2 1 3 12 7 5 3.5 4 2 4.5 6 7 5 1 4 6.5 5.5 8 13.5 6 7.5 19 2 10 15 6.5 17 7 9 7 5 5 11 31 6 15 20 17 5 9 3 4 7 22 11 10 7 14 15 12.5 10.5 9.5 11 2 1 8 24 5.5 6 4.5 1 2 1 9 11 17 14.5 10.5 13.5 15.5 13.5 12 14.5 11 17.5 12.5 9 14 11.5 12.5 13.5 12 13 23 14 15 14.5 12 10 12.5 10.5 12 7 25 9 15 2 16 11.5 15.5 13.5 9.5 7 21 8 2 19 1 22 I 23 21.5 22 5 19 18 22 18 18 21 18 15 16 19 23 21.5 10 10.5 4 9 7.5 6 21 16 20 23.5 1 22 16.5 19.5 20 17 20 24 22 12.5 12 14 19 17 19 18 19 7 13 9 8 20.5 16.5 24 24 24 24 13 11 11 18 19 21 12.5 21 20 14.5 18 17.5 20 13 24 7 22 17 23 18 8 16 23.5 5.5 9 23 23 22 16 11 27 21 19 11 20.5 24 18 16 14 17 30 24 21.5 21 23 20 19.5 9 21.5 23

sMaximum score from Table 12. 0Laboratories ordered by sum of ranks of 24-hr medians as in Table 26. cOutside limits for 9 samples: = 50.5 OL~J,~ to 174.6. dOutside limits for 8 samples; = 41.8 a0.05 to 158.2. Sum of ranks

With Without G G

~___ .-~-~- 44’ 2gd 58 54.5 42.5’ 19.5d 44” 40.5d 72 66.5 82.5 65.5 86 66 100.5 93.5 53 2gd 122 107.5 115.5 106.5 117.5 103 99 97 119.5 100.5 165 143 112.5 102.5 159.5 158.5d 152.5 140.5 163 155 138 120 161.5 148.5 149 143.5 160.5 149.5 182.5’ 161.5d



### At the other extremewerethelaboratories with unusually high sums of ranks, denoting low ranges,minimums, or maximums. As can beseenin Table 17,someof these laboratories were low in 2 or more of the 3 categories,somein only one. None had significantly high sumsfor the range, but laboratories 5 and 30 approached this. Laboratories 8, 13,and 27had unusually high sums(consistently low values)for the minimums and laboratories 16 and 30 had unusual maximums. Furthermore, the maximumsfor laboratories 5, 7, 18,and27werequite high, indicating atrend toward lowerthan usualmaximum scores.Laboratory variability will befurther illustrated in the discussionof median scores.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 295

Many other examplesof unusualvariation in the eyetestresultsmay beseen in the tables. For example,the tendencyfor eyehealingto occur-for thescores at 72hr and 7daysto belowerthan thoseat 24hr-was toward healingin 22of the24laboratories for material A (Table 3). However, the oppositetrend occurred for laboratories 7and 24.The overall mediansfor all laboratories were21.2,9.8, and 2.0at 24hr, at 72hr, andat 7days,respectively. Thosefor laboratory 24for thesesame periodswere 17,42, and 57. Similarly, no healingtrend for material F (Table 4) wasapparent for laboratories 12and24whilelaboratory 21hadmedianscores of 76,41, and7.5. For material L (Table 8)the 24-and48-hr and 7-day medianswere47,64, and76for laboratory 12as opposedto 56, 26.5, and 7 for laboratory 2.

TABLE 17 SIGNIFICANT AND NEAR-SIGNIFICANT SUMSOF RANKSFOR RANGE, MINIMUM,• RMAXIMUM-24-HR REFERENCE PROCEDURE,EYES~



### Range Minimum Maximum Laboratory No.

2 4 14 12 29 

### With Without

G G
45Sb 23.5h 52 32b 

### With Without G G

61.5 39b 28.5b 18.5& 51.5 35.5b 56.5 50 

### With Without G G
53 29b 42.5b 19.5” 44* 28b 44* 40.5b 58 30 172.5 154 182.5b 5 168 165 7 13 176.5b 154 27 179.5b 16Ob 8 159.Sb 18 16



### aNear-significant

=within 10 

### points

ofpertinent

95 %limitslisted. b With G, c10.05

limits = 50.5 to 174.5. 

### WithoutG, a,,05 limits =41.8to 158.2. 161.5b

155

149.5

148.5 158.5’



### -

It mustberecalledthat thesemedianscores arethosefor the 50th percentileof the 6 rabbits usedandfurther that the scorefor eachindividual rabbit isthe sumof 3components.The maximumpossiblescorefor anyeyeatany periodis 110;thisisthesumof the following maximums: cornea-degree of opacity and areainvolved, 80; iris-congestion, injection, etc., 10; and conjunctivae-redness, chemosis,discharge,20. Examplesof how the mediansof the laboratories differed in these3componentsof the total eyescoremaybeseen inTable 18.Heretheresultsofthelaboratoriesarepresented in the order of overall severity of action (seeTable 26), which will bediscussed later. Laboratory 14hadthelowestoverall sumof ranks indicating the highestgeneralreadingsfor severity of action whilelaboratory 30hadthehighestsumof ranks. In Table 18, for material G, different laboratories rated mediancornea1 damagefrom 0(laboratory 2)to 70(laboratory 25). Fifteen laboratories scored5to 10for irisinvolvement, while9 had mediansof 0. Thirteen laboratories had median conjunctival scoresabove 10; I1 had median scoresof 10or below.TABLE 18 s: 09 MEDIAN VALUES FORCORNEA, IRIS, AND CONJUNCTIVA COMPONENTS OFSCORE. REFERENCEMETHOD AT 24-HR READING

Laboratory Material G Material K Material L

No.“ Cornea Iris Conjunctivae Total Cornea Iris Conjunctivae Total Cornea Iris Conjunctivae

14 30 29 60 4 10 12 40 1 60 10 30 31 15 22 15 2 0 9 40 11 30 23 22.5 25 70 21 40 5 5 19 40 16 60 24 30 7 60 13 30 18 30 8 60 27 17.5 30 5 10

7.5 5 10 10 5 5 5 0 5 5 5 0 0 5 0 5 5 0 0 0 10 0 0 6

18 8 14 12 14 7 11 6 13 8 7 11 15 15 8 15 13 10 6 20 13 6 6 46 10

83.5 20 23 60 65 1s 82 0 51 5 28.5 20 29 7.5 7 2.5 58 5 46 0 41 0 82 0 55 0 26 5 48 12.5 80 0 49 0 70 7.5 36 0 50 0 83 0 26 0 11 5 Total

10 9 29 40 10 10 58 5 16 39 20 5 19 43 5 14 79 3s 5 12 52 5 14 34 20 5 16 47 5 10 14 25 5 10 39 0 8 13 40 2.5 10 52.5 0 8 28 20 5 8 32 g 2.5 10 21 20 5 12 32.5 : 0 9 12.5 40 5 13 56 0 12 20 20 0 11 32 : 0 8 8 20 5 12 35 8 0 11 12 20 2.5 14 0 35.5 g

7 7 20 5 10 35 9 0 12 12 22.5 0 14 47.5 5 12 22 5 5 12 22 5 17 32 10 5 15 30 5 17 21 0 5 17 22 5 11 16 0 5 15 21 0 8 14.5 2.5 0 1 5.5 0 12 12 0 0 12 12 0 6 6 5 0 3 10 0 4 4 0 0 4 8 0 4 4 15 0 6 20 0 9 13 5 0 9 14

eLaboratories ordered by sum of ranks of 24-hr mediar,s asin Table 26.TABLE 19

EYE-MEDIAN SCORE-REFERENCE PROCEDURE

Laboratory No. Median scorea at

___~- 24 Hr 12 Hr 7 Days

1 48 19 1 2 15 7 0 4 46.5 24 2 5 12.5 4 2 7 17 18.5 24.5 8 2 0 0 9 31 20.5 7.5 10 17 9 5 11 20.5 10.5 2 12 39 17.5 6 13 24.5 5 2 14 45 29.5 0 16 22 14 2 18 20.5 5 0 19 5 0 0 21 10 6.5 2.5 22 25 8 0
23 23.5 9 4 24 17 42 57 25 36 17 3 21 16.5 7.5 0 29 50 38 10.5 30 5 0 0 31 30 14 0 24 Hr 72 Hr I Days 24 Hr 72 Hr

- 46 49 64 24 47 10 31 49.5 21 43 15.5 60 16 17.5 16 76 35.5 33 15.5 28 24 64 15 30.5 ~-~ ___-~ __~ -~~

46 14.5 82 74.5 46 10 7 2 58 34.5 23 15 6 3 26 17.5 43.5 20.5 70 83 15 7 83 81 24.5 1 58 53 27 7 51 32.5 22.5 19 46 14 58 50.5 65 47 14 4 36 32 56 45 46 50 18 10 80 46 16 8.5 54 5.5 15 8 48 41 41 1.5 55 60.5 35 22 29 14 23 6 41 45 34 27.5 49 52 14 2 82 66 16.5 2 26 46.5 55.5 28 83.5 83 26 9.5 11 8 31.5 24 28.5 23 7 Days 24 Hr 72 Hr

37 35 23.5 0 40 49.5 5 55 21 13.5 26 25.5 85.5 12.5 10 73.5 25 18 6 33 22.5 21.5 34 34.5 66 28 37.5 33.5 41 48 0 7 48 49 58 58 11.5 19 14 9.5 I1 13.5 42 23.5 15 49 79 30.5 8.5 30.5 34 11 38.5 28.5 53 23.5 42 22 21 22.5 35 9.5 0 53 42 41 6.5 13 36 15 28.5 45.5 7 Days

0 9.5 6 28 5.5 5 12.5 24 51 24.5 25 26.5 2 12.5 9 5 22 5 40 19.5 0 41 51.5 27

0 Maximum possible score = 110.TABLE 19-Continued 5
Material

K L M

Median score” at Laboratory

___ ___- -__. .___ No. 24 Hr 72 Hr 7 Days 24 Hr 72 Hr 7 Days 24 Hr 72 Hr 7 Days

1 2 4 5 7 8 9 10 11 12 13 14 16 18 19 21 22 23 24 25 27 29 30 31 

### -

14 11 0 39 44 14.5 30.5 20 1 12.5 21.5 11 56 26.5 7 51 25.5 4.5 79 68 32 52 27 27 77 34.5 18.5 22 42 41.5 22 19.5 28.5 22 15.5 2 14.5 14.5 10 5.5 5.5 3 2 2 0 4 11.5 0 8 15 6.5 11.5 5 0 20 19 5 32 31 20 33 18 17 13 8.5 2 52.5 45.5 18 50 44 14 8 8 3 35 35 21.5 35 29.5 2 34 20 12 47 64 76 46 44 17 12 5 1 12 5 2 16 11 2 29 19.5 4 58 57 37 59 52 25.5 21 30.5 37.5 22 26.5 28 15 13.5 0 6 13 9 10 9 5.5 17.5 6 0.5 32 16 9 30 29.5 10.5 13.5 0 0 12 6 0 47.5 28.5 28 6 6 0 21 9.5 1 32.5 23 20.5 33.5 32.5 1 12 8 2 35.5 35.5 24.5 30 2.5 0 16 42 40 21 17 9 21 33 I 7 11.5 2 35 35 26.5 34 30 2 4 4 0 20 21 0 24 5.5 0 39 45 26.5 43 39.5 37 33 27 13 13 17.5 23 14 9.5 19 10 0 0 28 37 29 42 33 29 55 32.5 2.5 N P

-__

24Hr 72Hr 7 Days 24 Hr 72Hr



### -~. ~~ 11 2 32 7 52 20.5 22 13 2 0 10 2 21.5 16 40.5 15 33 20 39 41.5 16 10 55 36 9 3 5 0.5 32 11.5 6 10 30 27 11 0 17 16 10.5 3 2 1 33 33 15 18.5 31 9 0 45 25

4.5 23 0 10.5 61 20 6.5 23.5 11 0 1 1 0 21.5 2 12 18.5 0 7 20 4.5 2 27.5 4 12 45 35 2 16 9 19 42 30 0 12 12 0.5 15.5 4 1 11 0 0 4 0 0 30 29 0 27 6.5 0 10.5 16 1 15 10 0 10.5 2 15 30.5 12.5 0 2 0 0 26 13 7 Days

0 0 3.5 4 0 < 0 0 $

0 2 5
20.5 x 1 $ * 4.5 0 3 0 0 6.5 1 0 0 0 1 0 2

aMaximum possible score = 110.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 299

For material K, 11laboratories had median scores of 0 for cornea1 damage at 24 hr, while laboratory 4scored 60for this. Thirteen laboratories had 0for iris injury; 11rated
some discernible damage to the iris. Sixteen laboratories found iris damage from material L, 8 found none; 14 had conjunctival scores above 10; 10 laboratories had medians below 10.

TABLE 20

EYE-RANKS AND SUMS OF RANKS-24-HR MEDIAN



### Laboratory No. Material

A F 

### G J K L M N P 

### With Without G G

1 2 8 3.5 8 13 8 12 16.5 2.5 73.5 70 2 19 6 24 6 16 2 4 7.5 11 95.5 71.5 4 3 2.5 22 3 1 4 1 2 1 39.5” 17.5” 5 20 16.5 20.5 14 7 16.5 15 11 10 130.5 110 7 16 7 6 21 12 24 24 23.5 24 157.5 151.5 8 24 24 2 15 23.5 23 21 19 12 163.5 161.5* 9 7 12 8 10 10 13.5 10.5 12 14 97.0 89 10 16 5 11 9 14.5 3 5 3 13 79.5 68.5 11 13.5 15 14.5 13 20 10.5 7 5.5 7 106.0 91.5 12 5 9 7 5 3 6 6 4 2.5 47.5” 40.5* 13 10 21.5 17 24 18 21 18 14 15 158.5 141.5 14 4 4 14.5 2 5 1 2 1 4 37.5” 23* 16 12 19.5 5 19 8.5 16.5 19 20 18 137.5 132.5 18 13.5 18 10 22 22 22 17 22 16 162.5 152.5 19 22.5 19.5 13 16.5 4 15 20 7.5 19 137.0 124 21 21 1 9 

### 1 18 5 23 21 22 121.0 112 22 9 10 18 

### 11 8.5 12 9 10 6 93.5 75.5 23 11 11 16 7 18 9 13 16.5 8 109.5 93.5 24 16 21.5 12 16.5 11 18 16 13 20.5 144.5 132.5 25 6 14 3.5 18 21 10.5 8 18 17 116.0 112.5 27 18 16.5 20.5 23 23.5 19 14 23.5 20.5 178.5” 158 29 1 2.5 1 4 2 7 10.5 5.5 5 38.5” 37.5* 30 22.5 23 23 20 14.5 20 22 15 23 183.0” 160* 31 8 13 19 12 6 13.5 3 9 9 92.5 73.5 

### Sumof ranks

aOutside limits; q,.05 = 50.5 to 174.6. bOutside limits; CQ.,,~

= 41.8 to 158.2.



### The medianscores

arerecordedin Table 19for eyeinjury for eachofthe 24laboratoriesfor the9pertinent materialsfor the 3timeperiodsin which reactionswerenoted. Thesemedians

wererankedin Tables20,21, and22for eachsample at eachtimeperiod from 1for the highestscore,2 for the next highest,and soforth. The coefficientsof rank correlation, all positive, betweenmedianscores for eachof the laboratoriesfor the9materialsat the3readingperiodsaregiven inthe accompanying tabulation.

### 300 WEIL AND SCALA



### Material

- A F G 

### J K L M N P 24-Hr

7&r 24-Hr

OS. 

### 7-day 72-HI

7-Y& Median of median scores;

all the laboratories

24 72 Hr Hr 7

Days

0.764” 0.298 

### 0.753” 0.363 0.772“ 0.558 0.467 0.015 0.736” 0.631 0.802b 0.577 0.832* 0.842’ 0.799” 0.745” 0.678” 0.702” 0.584 21.2 9.8 2.0 0.776” 30.8 26.5 9.8 0.814’ 48.5 46.8 21.8 0.661 28.2 29.5 16.0 0.888* 14.2 15.2 7.0 0.643 32.8 27.8 20.2 0.829’ 30.2 19.0 1.5 0.632 19.2 10.8 0.8 0.662 20.8 7.8 0.0

nTwo-tailed critical valuesfor 0.05> P > 0.01 = 0.666. 

### b Two-tailed

criticalvalues

for 0.01 >P > 0.001 = 0.798. 

### c Two-tailed

criticalvalues

forP -e0.001 = 0.892.



### Thesecorrelations indicate that 

### with some materials, e.g., M, N, and P, readings at 24 hr would be sufficient. The later readings, at72 hr and at 7days, werewell correlated with the 24-hr readings. Note that at 7daysthe overall median scoresfor M, N, and P
wereclose to zero. For 8ofthe 9materials (all but J),the 72-hr readings werecorrelated with those at24hr. Note that, generally, the coefficients of correlation betweenthe 7-day and 72-hr readings were asgreat asor greater than those between the 7-day and 24-hr readings. With the good correlation between scores at 24 and at 72 hr, there does not appear to be sufficient reason to read the reactions at 72 hr. Generally, the ranking of materials, within any laboratory, wassimilar whether the 24-hr median or the median of all 3periods wasused. In 19of the 24 laboratories using the reference procedure, significant rank correlation occurred (Table 56). In the 5 laboratories with nonsignificant correlation, only 2, laboratories 5 and 18,were quite low. Various reasons for this can be determined on scrutiny of the data on individual samples. For example, the trend for increased injury with time for material K in laboratory 5wasabnormal, compared to most other laboratories, and wasalso aprime
reason for the poor intralaboratory correlation between 24-hr median and median of medians. The ranks for each laboratory were summed for the 9 pertinent samples, aswell as for these without material G (for the reasons previously discussed). Tables 20, 21, 22, and 23 give these ranks and their sums at 24hr, at 72hr, at7days, and for the median of the scoresfor these3time periods. The statistically significant sums (P c 0.05) and those close to significance-arbitrarily selected assum of ranks within 10points ofthe critical
sums-are presented in Table 24. Laboratories 12, 14, and 29 had consistently low sums of ranks at all time periods, while laboratory 4 had avery low sum of ranks only at 24 hr. This indicates that this latter laboratory recorded unusually high eyeinjury scoresat24 hr, but that their scores at 48 hr and at 7days were not unusual compared to the scores reported by the other laboratories.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 301

Similarly, laboratory 27 had consistently high sums of ranks at all time periods, indicating low eye injury scores. Similar trends were apparent for laboratories 8 and 18, while laboratory 7was close to significance and laboratory 30 was statistically significant only at 24 hr; laboratory 13 approached significance only in the median of the medians category.

TABLE 21

EYE-RANKS AND SUMS OF RANKS-72-HR MEDIAN



### Sumofranks

Material Laboratorv -.-.-----___- ~~
___ With Without

A F G J K L M N P 

### G G

- No.

1 6 5.5 4 15 17 4 12 19.5 4 87.0 83.0 2 17 5.5 24 2 7 14.5 11 16 22 119.0 95.0 4 4 1.5 20 18 1 13 4 5 5 71.5 51.5 5 21 24 19 14 3.5 18 14 11 10 134.5 115.5 7 7 7 1.5 23 13 23 22 23.5 19 139.0 137.5 8 23 20.5 3 19 15.5 20 20 19.5 17.5 158.0 155.0 9 5 14 8 16.5 10 10 13 8.5 22 107.0 99.0 10 13.5 12 16 10 19 3 2.5 10 14 100.0 84.0 11 12 16 5 8 20.5 7.5 9 6 15.5 99.5 94.5 12 8 1.5 11.5 3.5 8 1 2.5 I 1 38.0” 26.5b 13 19.5 22.5 17 3.5 23 24 16 13.5 12 151.0 134.0 14 3 3 10 I 9 2 1 2 2 33.0” 23.0b 16 10.5 17 14 21 6 14.5 15 17.5 9 124.5 110.5 18 19.5 19 23 22 14 22 17.5 22 15.5 174.5 151.5 19 23 20.5 11.5 20 12 11 23.5 12 22 155.5 144.0 21 18 8 7 12 22 12 17.5 13.5 22 132.0 125.0 22 15 9 21 11 18 16 6.5 4 3 103.5 82.5 23 13.5 15 15 13 20.5 6 21 23.5 13 140.5 125.5 24 1 10 9 7 3.5 19 5 8.5 6 69.0 60.0 25 9 22.5 6 16.5 15.5 7.5 8 17.5 11 113.5 107.5 27 16 18 13 24 24 17 19 21 17.5 169.5 156.5 29 2 4 1.5 5 2 5 10 3 8 40.5” 39.0b 30 23 13 22 9 11 21 23.5 7 22 151.5 129.5 31 10.5 11 18 6 5 9 6.5 15 7 88.0 70.0

’ Outside limits; Q.,,~ = 50.5 to 174.6. bOutside limits; CQ.~~

= 41.8 to 158.2.



### All of the laboratories that showedsignificant or near-significant divergenceon the medianbasis(Table 24) alsoshowedsignificant or near-significant divergence on the range, minimum, or maximum basis(Table 17).While 3 additional outlying laboratoriesareinthe latter table, thebestmethod of discrimination of divergent laboratories ison the basisof their medians. Themedianscores

(for anymaterialineachlaboratory) that werethelowestorhighest
arepresented,along with the medianof the medians,in Table 25.As with the range

### 302 WEIL AND SCALA



### betweenindividual rabbits, previously discussed, the rangein medianreadingsin some laboratories wasextremely low. For example, the range from the maximum to minimummediansfor laboratory 5wasonly 4(from 22to 26)ascontrastedto arangeof 81 (from 2to 83)for the mediansof laboratory 8. The rangefor 75‘4 of the laboratories
was30or more; therefore, thoselaboratories that hadsmallrangesin samplemedians, especiallylaboratories 5, 30, and 22, were unusual.

TABLE 22

EYE-RANKS AND SUMS OF RANKS-Y-DAY MEDIAN



### Laboratory No. A F G J K L M N P With Without G G

1 15 10 9 23.5 22.5 16 14 19 18 

### 147.0 138.0 2 20 11.5 23.5 15 9 19 7 8 18 

### 131.0 107.5 4 12 3 22 17 4 8 2 5 5 78.0 56.0 5 12 21 15 5 1 5 10.5 7 4 80.5 65.5 7 2 8 1 18 10 22 20.5 19 18 118.5 117.5 8 20 17.5 2 20 22.5 20 20.5 19 18 159.5 157.5 9 4 24 21 13.5 13 13 3.5 3.5 18 113.5 92.5 10 6 17.5 13 10 17 15 5 6 18 107.5 94.5 11 12 9 3 2 15 11 10.5 9.5 7.5 79.5 76.5 12 5 1 11 9 8 1 3.5 3.5 1 43.0” 32.0b 13 12 20 23.5 8 19.5 23 10.5 9.5 10 136.0 112.5 14 20 2 6.5 7 14 2.5 1 1 3 57.0 50.5 16 12 11.5 16 22 3 6.5 20.5 19 18 128.5 112.5 18 20 14 18 13.5 11.5 21 16 13 6 133.0 115.0 19 20 15 8 16 11.5 17 20.5 11.5 18 137.5 129.5 21 9 16 6.5 20 22.5 6.5 20.5 19 18 138.0 131.5 22 20 7 19 11 19.5 12 14 19 2 123.5 104.5 23 7 19 17 20 17 10 20.5 19 10 139.5 122.5 24 1 5 4.5 4 2 18 14 19 18 85.5 81.0 25 8 22.5 12 12 17 9 10.5 11.5 18 120.5 108.5 27 20 22.5 10 23.5 22.5 24 20.5 19 18 180.0” 170.0b 29 3 4 4.5 3 6 2.5 6 2 10 41.0” 36.5b 30 20 13 20 1 7 14 20.5 19 18 132.5 112.5 31 20 6 14 6 5 4 8 19 7.5 89.5 75.5 

### Material Sumofranks

0Outside limits; OL~.~~

= 50.5 to 174.6. bOutside limits; o(o.~~

= 41.8 to 158.2.



### Also presentedinTable25arethematerialsassociated with minimum,maximum, and median values for each laboratory. It is notable that, in 15 of the 24 laboratories, material G was the material associatedwith their maximum median. Contrariwise, material G wasthe minimum for laboratories 2and 4. In 13laboratories, materialsK and/or N wereranked minimum. However, they wererankedmaximum bylaboratories 4and30.Consistencyin theability to discerntherelative degreeofirritancy ofmaterials isimportant if the testisto beuseful. The data in Table 25 clearly indicate that, withINTERLABORATORY EYE AND SKIN COMPARISONS 

### 303

TABLE 23
EYE-RANKS AND SUM OF RANKS-MEDIAN OF MEDIANS Sum of ranks Laboratory

__ Material
-__- ~- With Without No. AFGJKLMNPG G

1 6 5.5 4 14 14 5 12 18 4 82.5 78.5 2 17 5.5 24 4.5 13 14.5 10 15 20 123.5 99.5 4 4 1 20 16.5 1 13 4 5 5 69.5 49.5 5 21 24 19 13 2 17 14 11 9 130.0 11l.U 7 7 7 1.5 22 12 23 22 24 19 137.5 136.0 8 24 23 3 18 23.5 22 20 19 17 169.5 166.5* 9 5 13 8 15 8 10 13 7.5 21 100.5 92.5 10 13.5 12 16 8 17 3 3 9.5 14 96.0 80.0 11 12 15 5.5 6 18.5 7.5 8 6 15.5 94.0 88.5 12 8 4 11.5 3 6 1 2 1 1 37.5” 26.0* 13 19.5 21.5 17 23 22 24 16 13 12 168.0 151.0 14 3 2 10 1 7 2 1 2 2 30.0” 20.0* 16 10.5 17.5 13 20 4 14.5 15 16.5 8 119.0 106.0 18 19.5 17.5 22 21 16 21 17.5 21 15.5 171.0 149.0 19 22.5 19.5 11.5 19 11 11 23 12 22 151.5 140.0 21 18 8 7 9.5 21 12 17.5 23 23 139.0 132.0 22 15 9 21 9.5 15 16 5.5 4 3 98.0 77.0 23 13.5 14 14 11.5 18.5 6 21 22 13 133.5 119.5 24 1 11 9 4.5 10 19 11 7.5 10 83.0 74.0 25 9 21.5 5.5 16.5 20 7.5 7 16.5 11 114.5 109.0 27 16 16 15 24 23.5 18 19 20 18 169.5 154.5 29 2 3 1.5 2 3 4 9 3 7 34.5” 33.p 30 22.5 19.5 23 7 9 20 24 9.5 24 158.5 135.5 31 10.5 10 18 11.5 5 9 5.5 14 6 89.5 71.5
’ Outside limits; ao.05= 50.5 to 174.6. *Outside limits; ~,.~s= 41.8 to 158.2. TABLE 24

SIGNIFICANT AND NEAR-SIGNIFICANT SUMS OF RANKS FOR

MEDIAN SCORE-EYE REFERENCE TE.W
Median of 24-Hr 48-Hr 7-Day medians ____- --~ Laboratory With Without With Without With Without With Without No. G G G G G G G G
33.0* 23.0* .~ 14 37.5* 23.0* 57.0 50.5 30.0* 20.0* 29 38.5* 37.5* 40.5b 39.0* 41.0* 36.5* 34.5* 33.0* 4 39.5* 17.5b 51.5 12 47.56 40.5* 38.0* 26.5* 43.0* 32.0* 37.5* 26.0b ~__ ~- 13 .___ 168.0 151.0 7 151.5 18 152.5 174.5 151.5 171.0 149.0 8 161.5” 148.2 157.5 169.5 166.5* 27 178.5* 158 169.5 156.5 180.0b 170.0b 169.5 154.5 30 183.0* 160.0*
’ Near-significant = within IOpoints of pertinent 95% limits listed. bWith G; czo.05

limits = 50.5 to 174.5. Without G; cz0,05 limits =41.8 to 158.2.

### 304 WEIL AND SCALA



### this test, certain materials are rated severely irritating by some laboratories and relatively non-irritating by others. The intralaboratory ranking of samples will be further discussed in the Results sections D, E, and F. The statistical parameters associated with the ranks of the 24-hr medians are summarized in Table 26. The laboratories are listed in order of lowest to highest sum of ranks, i.e., in order of those that read the highest, or most severe, to those with the lowest, or least severe, reactions. The 25th and 75th percentiles, Qi and Qj, are indications of variability, while the median, Q2, is an efficient measure of the midpoint. These are also presented in Table 26 and in Fig. 1. The measure, semi-interquartile range (SIQR),

TABLE 25
EYE: MAXIMUM-, MEDIAN-, AND MINIMUM-MEDIAN SCORESFORANY MATERIAL, %-HR REFERENCEMETHOD



### Medianscores Materialswith these medianscores Laboratory -~ ~~ -~ -__-
__ No. Maximum Median Minimum Range” Maximum Median Minimum

1 82 32.8 

### 11 71 G 2 56 19 7 49 

### L 4 79 52 23 56 

### K 5 26 22 22 4 

### GL 7 70 7.8 2 68 

### G 8 83 9 2 81 

### G 9 58 26.5 18.5 39.5 

### G 10 52.5 27 13 39.5 

### L 11 46 27 8 38 

### G 12 65 40 34 31 

### G 13 36 13.8 7 29 

### G 14 60 45.5 29 31 

### F 16 80 15.5 9 71 

### G 18 54 10.5 5 49 

### G 19 48 14.8 5 43 

### G 21 79 8 4 75 

### J 22 35.5 29.5 21 14.5 

### F 23 41 25.2 

### 11 30 

### G 24 49 16.5 10.5 38.5 

### G 25 82 18 7 75 

### G 27 26 

### 10 2 24 

### G 29 83.5 36 30.5 53 

### G 30 15 10.5 2 13 

### F,N 31 55 28.5 26 29 

### M J,M N P,A G LN G KLM,N K,L,M,N I,L M,N F+N,L A A+F,N P J,P K F,P K J,A+N K F,K+L J GA K F, M N J,L N F, M A A,M+N P N+P,G K P,A N A+N,K P P,J K P,J N K,M+N P GM P G,J P

4 (Maximum-minimum).
(Q3-Q,)/2, wasextremely largefor somelaboratories; it washigherthan 5for laboratories2,7, and21. For 75%ofthelaboratories the SIQR was4.8orless-the lowerthis measure,the greater the consistency in relative rank for the 9 samplesascompared with the other laboratories. For example, laboratory 4 had the lowestSIQR, 1.2.This laboratory ranked 1to 4on 8of the9samples;material G wasthe outlier. By contrast,TABLE 26 EYE REFERENCEMETHOD PARAMETERS

Laboratory Sum of ranks No. and Web With G Without G

14c 37.5’ 23.0d 29C 38.5’ 37.56 4c 39.5’ 17.F 12T 47.5” 40.5d 1T 73.5 70.0 1oc 79.5 68.5 311 92.5 73.5 22c 93.5 75.5 2G 94.5 71.5 91 97.0 89.5 111 106.0 91.5 23T 109.5 93.5 251 116.0 112.5 21G 121.0 112.0 5c 130.5 110.0 19c 137.0 124.0 16T 137.5 132.5 24T 144.5 132.5 71 157.5 151.5 13T 158.5 141.5 18C 162.5 152.5 8T 163.5 161.5d

271 178.5’ 158.0 20.5 17.2 23.2 3.0 14 to 23.5 3oc 183.0’ 160.0d 22.0 17.5 23.0 2.8 14.5 to 23 

### QZ Median

4.0 1.5 4.0 1.5 2.5 1.0 5.0 3.5 8.0 3.0 9.0 4.0 9.0 7.0 10.0 8.8 7.5 5.0 10.5 9.0 13.0 7.0 11.0 8.5 14.0 7.0 18.0 3.0 15.0 10.5 16.5 10.2 18.0 10.2 16.0 12.5 21.0 9.5 18.0 14.5 18.0 14.8 21.0 13.5

Rank Semi
### Q1 interquartile



### QS range
4.5 1.5 6.2 2.4 3.5 1.2 6.5 1.5 12.5 4.8 13.8 4.9 13.2 3.1 11.5 1.4 17.5 6.2 12.8 1.9 14.8 3.9 16.2 3.8 18.0 5.5 21.5 9.2 18.2 3.8 19.8 4.8 19.2 4.5 19.2 3.4 24.0 7.2 21.2 3.4 22.0 3.6 23.8 5.2 - Range

1 to 14.5 1 to 10.5 1 to 22 2.5 to 9 2 to 16.5 3to16 3 to 19 6to18 2 to 24 7 to 14 5.5 to 20 7to18 3.5 to 21 1 to 23 I to 20.5 4 to 22.5 5 to 20 11 to 21.5 6 to 24 10 to 24 10 to 22 2 to 24 Unusual features

8 of 9 = 4 or less

Ranked 1 to 4 except for G

2=1;4=21ormore

5 samples 21 to 24

All except G ranked 15 to 24; 5 of 9 more than 20

7 of 9 more than 20

aRanks of 24-hr medians. bSeeTable 1. cOutside limits; t(0.05= 50.5 to 174.6. dOutside limits; CQ.~~

= 41.8 to 158.2.306 WEIL AND SCALA



### laboratory 21had aSIQR of 9.2; its rank for 2 samples was 1while for 4 materialsit ranked 21or higher (out ofthe24laboratories and, therefore, the24possibleranks). Thereisno significant correlation betweenrelative sumof ranksfor medianscoreat 24 hr and the SIQR at that time. Ranking the latter, for the 21 laboratories that ran both theeyeandskin tests,from 1for the lab with the largestSIQR to 21for that with the smallest,the coefficient of rank correlation was-0.324. However, the correlation coefficient betweenthe severity-of-action rank and the rank for the sizeof the range between the maximum and minimum scorefor the eyes of individual rabbits was +0.606. Therefore, the laboratories that tendedto readlow in severity of reaction also tended to have lower variability betweenthe readingsfor individual rabbits,

-7T

20-

18-

16-

14L

5 2 

### 12-

10-

abRANK

1 Ql FIRST QUARTILE

2 Qz SECOND QUARTILE 3 43 THIRD QUARTILE 

## 3
1 3 

# ‘1I I I

i ?j ? [I

EYE 

# 1

b-a0 o) FIDUCIAL LIMITS 4 I I I I, I I I I I I I I ,I I I I I 10 2" 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 SUM OF RANKS
FIG. 1.Sum of ranks, median, and variability-Eye, 24-hr reference procedure.



### It isnotable, and probably to beexpected, that the relative position of the laboratories in sumof ranks(or medianscore)wasgenerally unrelated to the type of laboratory. Consultant laboratories (C)werein 3of the4lowestand2ofthe4highestsums of ranks; 38x, of the participating laboratories were C. One toilet goods or cosmetic laboratory (T) wasinthelowestand 1wasinthehighest4; the other highsum-of-ranks laboratory wasafood or industrial chemicalcompany(I). In variability, 3ofthe4lowest SIQRs wereassociatedwith aC and onewith aT 

### laboratory. Two ofthe laboratories with unusually highvariability inrank inrelation to the other laboratories(high SIQRs)
wereI and2weregovernmental (G)-the only 2governmental laboratories amongthe 24participants in the eyetest.INTERLABORATORY EYE AND SKIN COMPARISONS



### C. Skin Test-Reference Procedure 307



### The total irritation scores,asummationof the erythema, edema,and necrosisreactions noted at 24hr plusthoseat 72hr for eachrabbit, of the materials E, F, G, I, J, K, L, M, N, and0 arepresentedinTables27-36. Theorder, from top to bottom ineach table, isin severity of the primary irritation (PI) scorefor that material. The PI isthe average skin irritation scorefor the 8 rabbits usedfor eachmaterial: the higher the score,themoresevere

the reaction. As for theeyetest,therewasconsiderablevariation

TABLE 21
SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH ISOPROPYL MYRISTATE (MATERIAL 

### E)

Laboratory - No. 1 2 3


### 13 2 6 9 2 4 4 8 11 5 6 6 14 3 4 5 

### 5 5 5 5 19 3 3 4 25 2 2 3 8 2 2 3 31 

### 0 0 3 7 2 3 3 9 1 2 2 24 

### 1 2 2 26 1 1 1 12 

### 0 1 2 10 

### 0 1 1 4 

### 0 0 1 22 

### 0 0 0 23 

### 0 0 

### 0 30 

### 0 0 0 18 

### 0 0 0 21 0 

### 0 0 21 

### 0 0 

### 0 Orderedrabbit No.”

4



### -~ 11 8 6 5 5 5 4 3 4 4 3 2 1 2 2 1 1 

### 0 0 0 0 0 -5 6 7

11 15 19 9 9 9 6 7 7 6 7 7 6 6 6 5 6 7 4 5 5 4 4 

### 5
4 5 6 4 4 4 4 4 4 3 3 3 2 3 3 3 3 3 2 2 3 2 2 2 1 1 2 1 1 

### 1
1 1 2 

### 0 0 

### 0 0 0 

### 0 0 0 

### 0 No. with 8 

### necrosis
-b 4b 9 

### 0
7 

### 0
10 

### 0
7 

### 0 8 

### 0 9 1 I 

### 0
8 

### 0
5 

### 0
4 

### 0
4 

### 0 8 

### 0
4 

### 0
4 

### 0
3 

### 0
2 

### 0
4 

### 0 2 0
1 

### 0
1 

### 0 0 0 Primary

irritation score

5.2 3.8 3.1 2.9 2.8 2.6 2.1 1.9 1.9 1.8 1.5 1.2 1.2 1.1 0.9 0.7 0.4 0.4 0.4 0.1 0.1 0.0

’ Rabbits ordered by degree of 

### severityofreaction. b One rabbit died.



### among the laboratories betweenthe total scores for individual rabbits. The minimum andmaximum scorefor eachlaboratory for eachmaterial ispresentedin Table 37and therangebetweenthesescores inTable 38.Thelaboratoriesarelistedin orderof highest to lowestPI score,to bediscussed later. The maximum possible total scorefor arabbit, eitherfor the24-orfor the72-hr reading,isthesumof maximaof 8for erythema, 8for edemaand30for necrosis.All except2ofthelaboratories recordedminimum scores of zero; these2 had minimumsof 1.The maximum scorefor thelaboratories, however, varied considerably-from 6for laboratory 21to 46for 4laboratories: 11, 12, 13,and 14

### 308 WEIL AND SCALA



### With the minimums being practically zero, the ranges of scores are practically synonymous with the maximums (Table 38). These ranges were ranked from 1 to 22, as 22 laboratories participated in the reference skin test; the rank of 1 was given, for each material, to the laboratory with the largest range, 2to the next largest, etc. Therefore, a relatively low sum of ranks indicates consistently high ranges, high variability between minimums and maximums, or high irritation scores.

TABLE 28

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH 46 % AQUEOUS TRIETHANOLAMINE

LAURYL SULFATE (MATERIAL 

### F)

Laboratory - No. 1

12 21 31 31 2 21 13 20 25 4 10 23 23 7 11 6 22 8 14 

### 5 9 6 26 6 8 2 27 5 24 5 19 6 

### 5 6 4 3 7 2 30 

### 1 18 

### 0 21 

### 0 Orderedrabbit No.”

2 3 4 5

29 30 35 43 31 31 31 32 24 25 28 33 23 23 25 28 6 19 20 40 23 24 26 26 13 14 27 28 8 9 10 21 14 15 15 17 6 10 14 18 12 14 15 16 8 9 9 11 6 9 10 11 5 7 8 8 7 8 8 8 6 7 7 8 6 6 7 8 3 4 4 5 2 4 4 4 2 3 3 3 

### 0 0 0 0 

### 0 0 0 0 6 7 

### -__ 46 46 32 33 33 35 34 46 43 43 30 31 28 30 32 36 28 28 20 20 16 16 11 12 11 12 9 10 9 

### 9 8 9 

### 8 8 6 6 5 6 4 4 1 1 0 0 No.

__- 

### with 8 

### necrosis
---__~ ~ 46 8 33 8 38 8 -b 7* 44 6 31 8 30 5 44 4 32 8 22 6 16 0 13 0 13 0 12 0 9 0 10 0 11 0 6 0 6 0 5 0 6 0 0 0 

### Primary

irritation
score
18.5 15.9 14.8 14.2 13.7 13.4 

### 11.1 10.4 9.8 7.2 6.9 4.9 4.6 4.0 3.9 3.8 3.8 2.3 2.1 1.6 0.5 

### 0.0

0 Rabbits ordered by degree of severity of reaction. *One rabbit died.



### The significant, and near-significant, sumsof ranks arepresentedin Table 39. One laboratory, number 13,hadasignificantly low sumof ranks. With 8ofthe 10materials, laboratory 4 ranked 6th or lower of the 22 laboratories. While 3 other laboratories (11,12, and 14)hadnearly significantly low sums of ranks, only one(21)wasat or near significancefor high sum.The rangeswerethe highest,or tied with other laboratories for the highest, for 9 of the 10pertinent materials. Examination of the scoresof the individual rabbits for eachsample,exceptthat for M (Tables27-33,35, and36)shows that laboratory 21had scores of zero for every rabbit for eachof the 9materials. EvenINTERLABORATORY EYE AND SKIN COMPARISONS 

### 309

with material M, only 3 of the 8 spots had minimal reactions, 1. Thus of the 80 spots (10 materials, 8 rabbits each) 77 were completely negative. As mentioned earlier, the total skin irritation scores are the sums of those for erythema, edema, and necrosis. The total scores for the 8rabbits for these 3components at the 2time periods (24 and 72hr) for 2materials, F and K, are presented in Table 40 as an example of the variation between laboratories. The maximum total scores for the 8 rabbits for either time period are 32 for erythema, 32 for edema, and 120 for necrosis.

TABLE 29

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH 20-VOLUME CREAM PEROXIDE (MATERIAL G)



### Laboratory No.

31 13 9 26 12 14 

### 10 11 5 19 8 25 24 23 22 2 4 30 27 7 18 21 1

0 2 2
1 2 2
1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 

### - 2

2 3 2 4 2 2
1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 

### Orderedrabbit No.”

3

5 4 4 5 3 3 2
1 2
1 1 1 0 0 1 0 0 0 0 0 0 0 4 5 6 7

___--~ 6 6 8 19 4 7 

### 10 16 5 5 8 8 5 5 6 6 4 4 5 6 4 4 4 5 2 3 4 4 2 2 3 3 2 2 3 3
1 2 2 4
1 2 2 3
1 1 2 2 1 1 2 2 0 0 1 2 1 1 1 1 0 0 1 

### 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No. with 8 

### necrosis

20 2 -b 2” 8 0 8 0 8 0 7 0 5 0 8 0 4 0 5 1 3 0 3 0 2 0 3 0 2 0
1 0 1 0 1 0 1 0 0 0 0 0 0 0 

### Primary

irritation
score
4.1 3.3 2.6 2.5 2.1 1.9 1.4
1.2 1.1 1.1 0.8 0.6 0.5 0.4 0.4 0.2
0.1 0.1 0.1 0.0 0.0 0.0

a Rabbits ordered by degree of severity of reaction. bOne rabbit died.



### For material F, laboratory 21hadscores of 0, 0,and0andlaboratory 18scores of 1,1, and0at 24hr ascomparedwith 28,25, and85for laboratory 12and 28,26, and80for laboratory 31. Similar variability is apparent at 72 hr and for both time periods for material K. Recovery wasapparent (lower scores) at 72hr in somelaboratories, while others had much more severereaction at the latter than at the former period; e.g., laboratory 23had scores of 0to 75(material F) and0to 120(material K) for necrosis at 24 and 72 hr, respectively. Differences such asthesefor erythema, edema, and necrosis,aswellasfor the2timeperiods,shouldberemembered;theprimary irritation

### 310 WEIL AND SCALA



### scores, to be discussed hereafter, are summations of all of these and, therefore, mask these individual variations. Note also, in Table 40, as well as in Tables 27-36, that many laboratories never recorded scores for necrosis. Therefore, the primary irritation scores are presented in 2 manners-with and without the necrosis component-to indicate whether absence of such scoring affected the interlaboratory ranks.

TABLE 30 SKIN-REFERENCEMETHOD-SCORES OFINDIVIDUAL RABBITSAND PRIMARY IRRITATIONSCORES

WITH TRIETHANOLAMINE (MATERIAL 1)



### Laboratory -~- No. 1

13 2 

### 7 2 23 2 12 

### 1 10 2 26 2 

### 5 0 14 

### 1 19 

### 1 31 

### 0 30 

### 0 8 

### 0 4 

### 1
24 

### 0 11 0 22 

### 1 25 

### 0 9 

### 0 27 

### 0 2 

### 0 18 

### 0 21 

### 0 2

3 2 2 2 2 3 1 

### 1 2 0 0 0 

### 1 0 

### 0 1 0 0 0 

### 0 0 0 Orderedrabbit No.”

3

3 2 2 2 2 3 

### 1 1
2 0 0 I 

### 1 1 0 1 0 0 0 0 0 

### 0 4

8 5 3 2 3 3 2 

### 1
2 0 

### 1 1 1 1 0 1 1 0 0 0 0 0 5

9 5 3 4 4 4 3 3 2 2 

### 1 2 2 2 

### 1 1 1 0 0 0 0 0 6 7 8 No. 

### Primary with irritation necrosis score

22 30 -0 2b 5.5 5 18 19 2 3.6 3 3 15 

### 1 2.1
4 7 

### 10 0 2.0 6 6 6 

### 0 1.9 4 5 6 

### 0 1.9 3 4 5 

### 0 1.2 3 4 5 

### 0 1.2 3 3 4 

### 0 1.2 4 4 6 

### 0 1.0 1 2 9 

### 1 0.9 2 3 4 

### 0 0.8 2 2 3 

### 0 0.8 2 3 3 

### 0 0.8 3 3 5 

### 0 0.8 

### 1 2 3 

### 0 0.7 

### 1 1 3 

### 0 0.4 

### 1 2 2 

### 0 0.3 

### 0 2 2 

### 0 0.2 

### 0 0 

### 0 0 0.0 0 0 

### 0 0 0.0 0 0 

### 0 0 0.0

aRabbits ordered bydegree of severity. bOnerabbitdied.

The PI scores,

with necrosis

included, for eachlaboratory for eachpertinent material
arepresentedin Table 41, and thosewithout necrosisin Table 42. The 8laboratories which never recorded necrosisscoreswere4, 5, 8,9, 21,24,26,and 27.The maximum possiblePI score,including necrosis,is24; that without necrosiswould be 8. While laboratory 21recorded a PI of 0, laboratory 12had a PI of 22.6,both for material L. Elevenlaboratories had PI scores (Table 41)less

than 5for material Fwhile 8ofthe 22 had scores

higherthan 10.Even for the nonnecrosistotals (erythema andedemaonly) (Table 42),laboratory 18hadascoreof 0.5versus 

### 6.4for laboratory 23for F; 4laboratoriesrated L at2.0 

### or lower zwsus 3 

### at 7.2 

### or higher(out of amaximum PI scoreof 8). Note that, with material L, all of the 14laboratories that readnecrosison any sampleINTERLABORATORY EYE AND SKIN COMPARISONS 

### 311

recorded necrosis with this; but no necrosis was recorded in the other 8 laboratories
even with this sample. Ten of the 14 reporting necrosis sawit on all of the 8 rabbits examined (Table 33). Six of the laboratories reported necrosis on half or more of the samples, making the practically completely and unexplainable negative results (no erythema, edema, or necrosis) of laboratory 21 even more remarkable.

TABLE 31
SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH ETHOXYLATED LAURYL ALCOHOL (MATERIAL 

### J)

Ordered rabbit No.” Laboratory __-____ No. - 1 2 3 4 5 6 7 8 

### No. with Primary irritation necrosis score

25 5 6 17 19 19 20 22 23 6 8.2 23 6 IO 13 14 16 19 20 25 6 7.7 14 1 4 6 20 20 21 21 22 5 7.2 

### 13 5 9 9 9 17 18 28 -b 3b 6.8 11 6 7 8 8 9 11 12 25 1 5.4 9 7 9 9 10 11 12 13 13 0 5.2 22 4 4 9 9 10 13 14 15 6 4.9 31 1 2 5 5 5 7 10 11 0 4.3 31 4 6 7 9 14 15 15 22 7 4.3 7 0 1 2 2 4 19 19 21 3 4.2 12 5 6 7 8 9 9 10 13 0 4.2 10 4 5 6 7 7 7 9 12 1 3.6 5 5 5 5 5 6 7 7 9 0 3.1 8 4 5 5 6 6 7 7 7 0 2.9 24 4 5 5 6 6 6 7 8 0 2.9 30 3 3 4 5 6 7 7 7 0 2.6 4 2 3 3 4 4 5 8 10 0 2.4 2 3 3 4 4 4 4 5 7 0 2.1 19 2 3 4 4 4 5 5 6 0 2.1 27 0 2 2 2 4 6 6 9 0 1.9 18 0 1 2 2 2 3 3 5 0 

### 1.1 26 1 1 1 1 2 2 2 3 0 0.8 21 0 0 0 0 0 0 0 0 0 

### 0.0

’ Rabbits ordered by degree of severity. * One rabbit died.


### The ranks and sum of ranks, with and without the necrosis component, arepresented in Tables 43 and 44,with the significant and near-significant sums presented in Table 45. With or without necrosis, laboratories 11, 12, and 14 reported consistently low sums (severe reactions) and laboratories 18 and 21 had high sums (low PI scores). Other laboratories with high sums of ranks were27 and 30 on the with-necrosis basis, and 22 with necrosis excluded. It is notable that while all of those with high sums recorded necrosis on some or all of the samples, 3of the 5with low sums also recognized, and scored, necrosis on 2to 4 of the samples. The collaborative testing procedure clearly indicated that some laboratories consistently rated materials more irritating while other laboratories just asconsistently rated the same materials lessirritating than the ma,jority ofthe participating laboratories.

### 312 WEIL AND SCALA



### The interlaboratory relative sums of ranks of PI, with and without necrosis, are presented in Table 46. The coefficient of rank correlation was higher than +0.85, a statistically significant figure. The laboratories that ranked 1, 2, 3, and 4 with necrosis
scores ranked 1,3,2, and 4 without necrosis; those which ranked 19.5, 19.5,21, and 22 with necrosis ranked 21, 19, 18,and 22, respectively, without scores for necrosis. Thus,
even though some laboratories did not score necrosis on any spot for any material, while at least 1score of necrosis was seen for 8 of the 10samples, those which tended to have high PI scores with necrosis also rated relatively high when scores for necrosis (when present) were subtracted.

TABLE 32

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH DECAETHOXY OLEYL ETHER (MATERIAL K)

- 

### Laboratory - No. I

23 24 31 6 13 11 22 9 14 11 9 9 12 7 26 7 10 6 11 6 7 1 5 5 4 4 2 4 25 4 24 4 19 4 30 4 8 4 18 2 27 0 21 0 2 3 4 5 6 

### 7

25 25 25 25 26 27 16 28 29 29 29 32 12 19 21 21 22 23 10 10 14 15 15 25 12 12 12 13 14 16 9 10 11 11 12 12 9 10 10 10 11 12 7 8 8 8 9 9 6 6 7 8 9 10 6 8 8 8 9 9 2 3 5 5 5 19 6 7 7 8 8 8 5 6 6 7 8 9 5 6 6 7 8 8 4 5 5 6 7 8 4 5 5 6 6 7 4 4 5 5 6 7 4 4 4 5 5 6 4 4 4 5 6 6 2 2 3 3 5 9 1 2 3 5 6 7 0 0 0 0 0 0 

### OrderedrabbitNo.” No. 

### Primary with irritation 8 

### necrosis score

27 8 12.8 32 7 12.6 -b 5b 9.2 25 8 1.7 16 8 6.6 12 0 5.4 14 0 5.2 11 0 4.2 13 0 4.1 11 0 4.1 20 2 3.8 9 0 3.6 9 0 3.4 8 0 3.2 9 0 3.0 7 0 2.8 8 0 2.7 8 0 2.5 6 0 2.4 9 2 2.2 8 0 2.0 0 0 0.0

’ Rabbits ordered by degree of severity. b One rabbit died.



### Certain unexplained anomaliesoccurred which kept somelaboratories from having outlying sumsof ranks. SamplesM, N, 0, and Pweresentto the laboratories several monthslaterthan thefirst 12materials.Therefore, inmostlaboratories which hadcompletedthe first 12,they weretestedlater. Laboratory 13had relative ranksof no higher than 4in samples

A to L, whileit ranked 12to 19.5on M, N, and0 (Tables43and47) resulting inasumof ranksof 69.5(95“/,lower limit is55.1).Laboratory 31hadranksof
nohigherthan 10for the first 12samples, but ranks of 19and 19.5on N and0. For theINTERLABORATORY EYE AND SKIN COMPARISONS 

### 313

first batch of 12samples, byway of contrast, laboratory 18had 6ranks of20 or higher, but ranked 7.5 to 11.5 for M, N, and 0. These differences may have resulted from changes in technicians, in stock of rabbits, in the season of the year, etc.

TABLE 33

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH LINOLEIC DIETHANOLAMIDE (MATERIAL L)

Laboratory Ordered rabbit number” No. Primary

--.-___ ___- with irritation 

### No. 1 2 3 4 5 6 7 8 necrosis score

12 41 45 45 46 46 46 46 46 8 22.6 25 30 35 39 40 41 41 41 42 8 19.3 13 22 27 29 30 36 36 36 -b 7b 15.4 10 20 22 25 26 29 37 41 42 8 15.1 22 25 25 29 30 30 30 31 32 8 14.5 31 29 29 29 29 29 29 29 29 8 14.5 11 12 12 13 33 34 34 44 46 5 14.2 23 14 28 28 29 30 30 30 31 7 13.8 14 17 18 20 20 21 21 25 28 8 10.6 2 17 17 18 18 19 19 21 21 8 9.4 19 10 14 17 18 18 19 26 -= 7’ 8.7 9 15 16 16 16 16 16 16 16 0 7.9 18 9 14 14 15 15 16 16 19 8 7.4 4 IO II 12 13 13 13 13 13 0 6.1 5 9 10 10 11 11 11 12 12 0 5.4 27 8 8 9 10 11 11 11 12 0 5.0 7 1 1 2 6 13 14 20 21 4 4.9 24 8 9 9 10 10 10 10 11 0 4.8 30 6 6 6 7 9 10 13 13 2 4.4 26 6 7 7 8 9 9 11 11 0 4.2 8 3 3 7 8 8 9 10 11 0 3.7 21 0 0 0 0 0 0 0 0 0 0.0

’ Rabbits ordered by degree of severity of reaction. ’ One rabbit died. ’ One rabbit injured in fight; skin not read.



### The statistical parameters associated with the PI scores, including the necrosis component when present, are summarized in Table 47 and Fig. 2. The laboratories are listed in order oflowestto highest sum of ranks, i.e. in order ofthosethat read the highest (most severe)to those with the lowest (least severe) reactions. The 25th and 75th percentiles (Qi and Q& the measures ofvariability (the range and the SIQR), aswell asthe median ranks are included in Table 47. Asfor the eyetest, the SIQR wasquite high for
some laboratories and low for others. The median SIQR for the skin was3.5. Laboratory 21had the lowest SIQR for the skin (0.7) aswell asthe highest SIQR for the eyetest (9.2). The 2 laboratories with the highest skin SIQRs (laboratories 13 and 22), with ranks of 1.5for the skin, ranked 12.5 and 20 of 21 laboratories for the eyetests. These comparative SIQRs and their ranks are presented in Table 48. The coefficient of rank correlation between the eyeand skin SIQR wasnearly zero ($0.00033). Therefore, there

### 314 WEIL AND SCALA



### wasno relationship in relative variability in rank between the laboratories on the eye and on the skin tests. Ordinarily, a low SIQR is more desirable than a high one. It indicates that, for the samples tested, the laboratory consistently had low variability around its median rank; from its 25th to 75th percentiles (Q1 and QJ. However, while this is true for laboratory 

### 21, with a median rank of 21.8 and with aQ, and Qj of 20.6 and 22.0, this laboratory attained these consistently high ranks by scoring a zero PI reaction for almost every 

### rabbit. By contrast, the laboratory with the next smallest skin SIQR, laboratory 24, had PI scoresranging from 0.8 to 4.8.

TABLE 34

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY

IRRITATION SCORES WITH n-BIJTYL ALCOHOL (MATERIAL 

### M)

Laboratory - No. 1

- -____- 12 12 II 8 14 3 10 2 25 2 31 0 31 0 2 0 26 3 23 0 18 0 5 3 4 1 24 0 19 I 9 0 27 0 8 0 7 0 13 0 21 0 30 0 22 0 2

- 12 8 4 3 3 0 12 0 4 I 1 3 2 1 1 

### 0 0 0 0 0 0 0 0 ~- 3 

### -

5

13 14 

### 15 9 10 I1 

### 8 10 

### 13 3 3 5 4 5 8 0 0 0 16 22 24 0 1 1 6 6 7 2 2 2 2 2 2 4 4 4 2 3 4 2 3 3 I 2 2 0 0 I 0 1 2 0 1 

### 1 0 1 

### I 0 0 0 0 0 0 0 0 1 0 0 0 Orderedrabbit No.”

6

- 22 21 14 25 17 0 24 I 8 3 2.5 4 4 3 3 I 3 2 2 0 0 1 1 

### - 7 8

46 46 21 29 14 46 26 34 25 35 0 0 31 32 25 25 9 10 

### 3 24 6 18 5 5 4 4 3 4 3 4 3 12 3 4 2 4 2 2 2 4 0 6 1 

### 2 1 1 

### No. Primary

with irritation necrosis score .~__ ~_ ~~~-~

- 3 11.2 3 7.3 4 7.0 3 6.3 3 6.2 0 5.0 7 5.0 2 3.3 0 3.3 I 2.3 1 2.1 0 2.0 0 1.5 0 1.2 0 1.1 0 1.1 0 0.8 0 0.6 0 0.5 0 0.4 0 0.4 0 0.3 0 0.2

eRabbits ordered by degree of severity of reaction.



### The coefficient of rank correlation between the sum of ranks of PI and the SIQR (Table 47)wasnot significant, +0.401. Nevertheless, the correlation coefficient between rank of sum of ranks ofthe laboratories for relative skin irritation, the PI, and the rank of the sumof ranks of the laboratories for rangeof scores for individual rabbits (pre

### sented in Table 39)was+0.847, avery significant correlation. Thus, the laboratories that tended to have the highest PI also tended to havethe smallest variation between readings
on individual rabbits.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 315

TABLE 35

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH METHYL ETHYL KETONE (MATERIAL 

### N)

Laboratory ~~ No. 1 2 3 4 5 6 7 

### No. Primary with irritation 8 necrosis score

12 4 4 4 6 7 7 8 12 0 3.2 14 4 5 5 5 6 6 8 10 0 3.1 10 0 1 2 2 3 3 13 24 2 3.0 26 2 2 4 4 4 4 6 9 0 2.2 11 0 2 2 3 4 5 6 6 0 1.8 25 0 2 2 2 2 4 5 6 0 1.4 5 1 1 2 2 2 3 4 4 0 1.2 24 0 1 1 2 2 2 2 3 0 0.8 19 0 0 1 1 1 2 2 3 0 0.6 7 0 0 1 1 1 2 2 2 0 0.6 2 0 0 0 0 0 0 1 3 0 0.2 18 0 0 0 0 0 0 0 3 0 0.2 22 0 0 0 0 0 0 1 1 0 0.1 23 0 0 0 0 0 0 1 1 0 0.1 30 0 0 0 0 0 0 1 I 0 0.1 4 0 0 0 0 0 0 0 1 0 0.1 8 0 0 0 0 0 0 0 0 0 0.0 9 0 0 0 0 0 0 0 0 0 0.0 21 0 0 0 0 0 0 0 0 0 0.0 27 0 0 0 0 0 0 0 0 0 0.0 31 0 0 0 0 0 0 0 0 0 0.0 13 0 0 0 0 0 0 0 0 0 0.0 Ordered rabbit No.”

’ Rabbits ordered by degree of severity of reaction.



### D. Intralaboratory SampleRanks 

### The previous sections included discussion ofthe results wherethe relative irritancy of pertinent samples tested wasusedto rank the laboratories. Another aspect ofthesetests isthe manner in which the laboratories ranked the samples. In other words, relatively, do most laboratories rate low-irritating materials differently from those of a higher degree ofirritancy ?Therefore, for each laboratory, the pertinent materials wereranked from 1to N; the rank of 1being assigned to the material with the highest irritation score, 2to that next most irritating, etc. The ranks were summed for each material and are presented for the eyetestsin Tables 49,50, and 51and for the skin testsin Tables 52and 53. Major differences did occur; e.g., laboratories 2 and 4 rated material G asthe least irritating of the 9 materials on the eye while 16 laboratories rated G as the most irritating. The sums of ranks, and designations of deviation from the respective 95%probability limits, are presented in Table 55.With only 9materials for the eyetest (or 8if material G isnot usedin thesetabulations) and with 10for the skin test, lessthan 1ofthese might be expected to be unusually high or low in relative rank if the laboratories did not consistently rate the materials high or low. This expectation was not borne out, however.

### 316 WEIL AND SCALA



### Materials F, G, and L were rated consistently as more irritating to the eyes than the other materials while, in one or more of the various categories, reference or nonreference, materials A, K, N, and P were ranked as relatively nonirritating to the eyes (compared with the other materials tested).

TABLE 36

SKIN-REFERENCE METHOD-SCORES OF INDIVIDUAL RABBITS AND PRIMARY IRRITATION SCORES WITH METHYL ISOBUTYL KETONE (MATERIAL 

### 0)

Ordered rabbit No.” Primary

No. 1 2 3 4

9 7 4 2 3 2 2 2 2 2 2 0 1 1 1 1 0 0 0 0 0 0 0 

### No.

5 

### with irritation 6 7 8 

### necrosis score Laboratory

__

12 6 9 9 11 3 6 6 14 2 2 4 26 2 2 2 24 1 2 3 25 1 2 2 9 0 

### 1 2 18 0 

### 0 1 5 1 

### 1 2 10 0 

### 0 1 30 1 

### 1 1 13 0 

### 0 0 23 0 

### 0 1 7 0 

### 0 1 27 0 

### 0 0 19 0 

### 0 0 8 0 

### 0 0 2 0 

### 0 0 31 0 

### 0 0 31 0 

### 0 0 22 0 

### 0 0 4 0 

### 0 0 21 0 

### 0 0 11 11 11 12 0 4.9 7 8 8 9 0 3.4 6 7 7 8 0 2.5 4 5 5 7 0 1.8 3 3 4 4 0 1.4 2 3 4 5 0 1.3 2 4 4 5 0 1.2 2 2.5 5 7 0 1.2 2 3 3 4 0 1.1 3 3 4 5 0 1.1 2 3 3 3 0 1.0 0 2 3 9 1 0.9 1 2 2 3 0 0.6 1 2 2 2 0 0.6 1 2 2 3 0 0.6 1 1 2 2 0 0.4 1 1 1 2 0 0.3 0 1 2 2 0 0.3 0 0 0 0 0 0.2 0 0 1 4 0 0.2 0 0 1 1 0 0.1 0 0 0 0 0 0.0 0 0 0 0 0 0.0

aRabbits ordered by degree of severity of reaction.



### Similarly, F, L, and K wererelatively irritating and G, I, N, and 0 relatively nonirritating in the skin test. Therefore, the laboratories, on the whole, ranked the materialsmuch more consistently than might havebeenexpectedby chance,if the use ofthesemethodsdid not allow alaboratory to show,by itsown testingfacilities, which material wasrelatively more irritating than the others. Much more agreementon the relative ranking of thesamples bythe laboratories wasfound than ontherelative ranking of the laboratories by the samples (intra- asopposedto interlaboratory ranking). It isinterestingthat material G wasthe mostirritating sampletestedonthe eyebut the leastirritating on the skin (Table 55). Comparisons(Table 54)weremadebetweenthe correlation of therelative irritationTABLE 37

MINIMUM-MAXIMUM SCORE FOR REFERENCE PROCEDURE SKIN TEST-INDIVIDUAL RABBITS

Laboratorv

- No.” E Material

F G I J K L M Any N 0 material

12 14 11 13 10 25 31 23 26 5 9 2 19 24 22 7 8 4 18 30 27 21 Any laboratory O-4

3-10 5-7 2-19 O-4 2-9 O-8 O-4 l-8 5-7 l-4 4-9 3-8 1-4 o-2 2-5 2-7 &3 o-l o-2 O-1 All 0

O-19 21-46 2-8 l-10 5-l 3 7-14 41-46 12-46 4-12 6-12 &46

5-22 2-7 l-5 l-22 11-16 17-28 3-46 4-10 2-8 1-46 6-44 O-8 O-5 6-25 &I1 1246 8-29 O-6 3-9 C46 2046 2-l 6 2-30 5-28 11-23 22-36 e-4 All 0 o-9 O-46 23-31 1-5 2-6 4-12 6-13 20-42 2-34 O-24 o-5 o-42 4-44 o-3 o-3 5-23 4-9 30-42 2-35 O-6 l-5 o-44 31-33 O-20 o-6 l-22 6-32 All 29 o-32 All 0 O-4 o-33 7-30 O-3 2-15 6-25 24-27 14-31 O-24 O-1 o-3 O-30 6-13 1-8 2-6 1-3 7-l 1 611 3-10 2-9 2-7 1-13 6-11 o-4 O-l 5-9 5-9 9-12 3-5 l-4 l-4 o-12 6-16 2-8 O-2 7-13 9-12 15-16 o-12 All 0 o-5 O-16 21-38 o-1 All 0 3-7 4-8 17-21 O-25 o-3 o-2 O-38 6-10 l-5 14 2-6 4-8 l&26 1-4 o-3 O-2 o-26 5-9 o-2 o-3 4-8 4-7 8-11 @4 o-3 l-4 o-11 8-32 o-2 l-3 4-15 9-25 25-32 O-l o-1 o-1 O-32 2-6 All 0 2-19 o-21 l-20 1-21 o-2 o-2 o-2 O-21 2-l 3 o-3 o-4 4-7 4-6 3-11 O-4 All 0 o-2 o-13 3-6 o-1 l-3 2-10 4-9 lo-13 l-4 o-1 All 0 O-13 &6 All 0 All 0 O-5 2-9 9-19 O-18 O-3 O-7 o-19 l-5 Cl o-9 3-7 4-8 6-13 O-2 o-1 l-3 o-13 5-12 O-l O-2 o-9 O-8 8-12 O-4 All 0 o-3 o-12 All 0 All 0 All 0 All 0 All 0 All 0 O-6 All 0 All 0 O-6

O-46 O-20 O-30 O-28 O-32 046 O-46 o-1 2 o-12 

### -

’ Laboratories ordered by sum of ranks for primary irritation as in Table 47.

### 318 WEIL AND SCALA



### rank of the materials in eachlaboratory and the overall interlaboratory rank of the
samematerials. For example, from Table 49for laboratory 4:

Material Rank in Overall rank in

laboratory 4 alllaboratories

A 8 6 

### F 3 2 G 9 1 

### J 5 5 

### K 1 9 L 6.5 3 

### M 2 4 N 6.5 7 

### P 4 8



### TABLE 38

RANGE OF SCORES FOR REFERENCE PROCEDURE SKIN TESTINDIVIDUAL RABBITS’



### Laboratory - No.~ E Rangefor material

F G I J K L M N 

### 0

12 4 25 6 

### 9 8 7 5 34 8 6 14 7 17 5 4 21 4 

### 11 43 6 6 

### 11 2 38 8 4 

### 19 5 34 21 6 6 13 17 26 14 28 23 12 14 4 0 9 10 4 8 4 4 8 7 22 32 24 5 25 7 40 3 3 

### 18 5 12 33 6 4 31 8 2 17 6 

### 21 26 0 32 0 4 23 4 23 3 13 

### 19 3 17 24 1 3 26 7 7 7 4 2 4 5 7 7 5 5 2 5 4 

### 1 4 4 3 2 4 3 9 3 

### 10 6 2 6 3 

### 1 12 0 5 2 5 

### 17 1 0 4 4 4 25 3 2 

### 19 5 4 4 3 4 4 16 3 3 2 24 3 4 2 3 4 3 3 4 3 3 22 2 24 2 2 11 16 7 1 1 1 7 3 4 0 17 21 

### 19 20 2 2 2 8 5 11 3 4 3 2 8 4 0 2 4 3 3 1 2 8 5 7 3 1 0 18 

### 1 6 0 0 5 7 12 

### 18 3 7 30 2 4 1 9 4 4 7 2 1 2 27 1 7 1 2 9 8 4 4 0 3 21 0 0 0 0 0 0 0 6 0 0

nRange = maximum minus the minimum. bLaboratories ordered by sum of ranks for primary irritation as in Table 47.TABLE 39

RANK AND SUM OF RANKS OF RANGES LISTED IN TABLE 38

Rank of range for material Laboratory No.“

12 14 11 13 10 25 31 23 26 5 9 2 19 24 22 7 8 4 18 30 27 21 E F

_-~ .~~ .~__ 10 4 4 7.5 17.5 2 1 3 10 11 4 1 2 21 10 6 4 12.5 17.5 15 13.5 10 7 7.5 7 17.5 13.5 17.5 17.5 5 13.5 17.5 7 9 13.5 20 20.5 14 17.5 17.5 20.5 12.5 22 22 G I

.--__ -... J

5.5 4.5 11 7 9 3 3 9 5.5 2 1 1 9 9 11 12 13 7 1 6 3 12 3 5.5 4 9 21 9 19 17 5.5 16.5 13 17.5 21 17 9 13 17 14.5 13 17 14.5 16.5 8 21 2 3 12 9 20 17.5 16.5 11 21 21 14 17.5 4.5 17 17.5 16.5 9 21 21 22 K

7 14.5 10 4 7 10 1 19 14.5 14.5 19 14.5 14.5 19 3 2 21 10 7 14.5 5 22 L M



### - 14.5 2 9 1 1 8 6 14.5 2 4.5 7.5 3 21.5 4.5 4 7 14.5 11 18.5 20 20 10 16.5 6 5 17.5 18.5 14.5 12 22 3 20 10 14.5 12 17.5 7.5 9 12 20 16.5 14.5 21.5 12 N

2 5 5 19.5 1 5 19.5 14.5 3 7 19.5 9.5 9.5 9.5 14.5 12 19.5 14.5 9.5 14.5 19.5 19.5 0

4 4 4 1 7 9.5 9.5 12.5 7 12.5 7 17 17 12.5 20 17 17 21.5 2 17 12.5 21.5 Sum of

ranks

_~.- 2 64.5 L-4

w 64.0 F 65.0 53.0b s 71.5 5 72.0 89.0 E 93.5 3 100.5 150.0 5 134.0 133.5 w 127.0 2
149.5 c)
133.0 2 111.0 z 139.0 Fl 154.0 z 125.5 152.0 144.0 204.5b

aLaboratories ordered by sum of ranks for primary irritation asin Table 47. dOutside limits; CG,.~~

= 55.1 to 174.9. w 5,TABLE 40 ERYTHEMA, EDEMA, AND NECROSIS COMPONENTS OF TOTAL SCORE FOR MATERIALS F AND K-REFERENCE METHOD, SKIN
Material F Material K

Total score of 8 rabbits for Total score of 8 rabbits for z 0

Erythema Laboratory

____ --- No.” 24Hr 72 Hr
__~~~ ~___ 12 28 30 14 22 20 11 19 20 13 16 21b 10 15 17 25 17 21 31 28 SC 23 30 30 26 25 16 5 13 20 9 28 32 2 19 28 19 14 12 24 17 19 22 16 18 7 9 16 8 23 20 4 13 16 18 1 3 30 7 12 27 13 22 21 0 0 Edema Necrosis

24 Hr 72 Hr 24 Hr

~.__ 85 0 40 20 40 60 80 0 0

E! 65 0 0 25 0 0 0 0 0 0 0 72 Hr

25 13 26 14 17 18 26 15 21 9 23 15 15 14 10 0 15 4 1 0 8 0 

### __28 10 22 27b 15 23 SC 27 17 18 28 0 20 13 3 8 16 4 3 6 21 0 Primary Erythema Edema Necrosis Primary



### - irritation
score 24 Hr

100 50 40 95h 110 80 120 75 0

E”o 110 0 0 75 0 0 0 0 0 0 0 18.5 24

7.2 23 10.4 19 14.2 19 13.4 16 13.7 8 15.9 29 11.1 24 4.9 22 3.8 14 6.9 19 14.8 16 3.8 11 3.9 14 9.8 16 2.1 15 4.6 14 2.3 16 0.5 5 1.6 12 4.0 4 0.0 0 72 Hr 24Hr

~ ____. 23 22 23 26” 20 22 s” 32 24 15 27 15 12 24 22 15 15 19 13 20 14 0 16 10 8 17 14 1 6 6 16 9 10 6 5 0 0 0 I 5 2 1 0 0 irritation 72 Hr 24 Hr 72 Hr score
20 0 6 0 15 0 21b 0 15 0 17 0 SC 65 22 0 10 0 20 0 30 0 15 0 15 0 26 0 0 25 0 0 3 0 14 0 5 0 7 0 14 0 0 0 0 5.2

45 6.6 0 4.1 50b 9.2 0 4.1 0 3.0 s 95 12.5 r

120 12.8 0 4.2 g

E”o 3.6

54 x

F 0 3.2 ?+
0 2.7 0 4.0 60 7.7 30 3.8 0 2.4 0 3.4 10 2.2 0 2.5 0 2.0 0 0.0
’ Laboratories ordered by sum of ranks for primary irritation as in Table 47. bScore is for 7 rabbits as one died or was injured in a fight. c“Large scab obscured any possible reading of erythema or edema at 72 hr.” d“Superficial eschar which healed without scar.”INTERLABORATORY EYE AND SKIN COMPARISONS 

### 321

TABLE 41

SKIN-SCORE OF REFERENCE METHOD (WITH NECROSIS SCORE)



### Laboratory No. E 

### F __ G

2 3.8 14.8 0.2 4 0.7 2.3 

### 0.1 5 2.8 3.8 

### 1.1 7 1.8 2.1 

### 0.0 8 1.9 4.6 0.8 9 

### 1.5 6.9 2.6 

### 10 0.9 13.4 1.4 

### 11 3.1 10.4 1.2 12 

### 1.1 18.5 2.1 

### 13 5.2 14.2 3.3 14 2.9 7.2 1.9 18 

### 0.1 0.5 0.0 19 2.6 3.8 

### 1.1 21 

### 0.0 0.0 0.0 22 0.4 9.8 0.4 23 0.4 

### 11.1 0.4 24 1.2 3.9 

### 0.5 25 2.1 13.7 0.6 26 1.2 4.9 2.5 27 

### 0.1 4.0 

### 0.1 30 0.4 1.6 

### 0.1 31 1.9 15.9 

### 4.1

- Material

1 J

0.0 2.1 0.8 2.4 1.2 3.1 3.6 4.2 0.8 2.9 0.3 5.2 1.9 3.6 0.8 5.4 2.0 4.2 5.5 6.8 1.2 7.2 

### 0.0 1.1 1.2 

### 2.1 0.0 0.0 0.7 4.9 2.1 7.7 0.8 2.9 0.4 8.2 1.9 0.8 0.2 1.9 0.9 2.6 

### 1.0 4.6 

### K L M N 0

3.2 9.4 3.3 0.2 0.3 3.4 6.1 

### 1.5 0.1 0.0 3.6 5.4 2.0 

### 1.2 1.1 3.8 4.9 

### 0.5 0.6 0.6 2.4 3.7 0.6 

### 0.0 0.3 5.4 7.9 

### 1.1 0.0 1.2 4.1 

### 15.1 6.3 3.0 

### 1.1 4.1 14.2 7.3 1.8 3.4 5.2 22.6 11.2 3.2 4.9 9.2 

### 15.1 0.4 0.0 0.9 6.6 

### 10.6 7.0 3.1 2.5 2.2 7.4 2.1 0.2 1.2 2.7 8.7 

### 1.1 0.6 0.4 

### 0.0 0.0 0.4 

### 0.0 0.0 7.7 14.5 0.2 

### 0.1 0.1 12.8 13.8 2.3 

### 0.1 0.6 2.8 4.8 1.2 0.8 0.4 3.0 19.3 6.2 1.4 1.3 4.2 4.2 3.3 2.2 1.8 2.0 

### 5.0 0.8 

### 0.0 0.6 2.5 4.4 0.3 

### 0.1 1.0 12.6 14.5 

### 5.1 0.0 0.2



### The rank correlation coefficient for the preceding text table (page 318) is -0.379. The significance notation in Table 54 is the opposite of that in the other tables in this presentation. Instead of denoting the laboratories that significantly correlated well with the overall intralaboratory ranking of the samples, the laboratories that lacked significant correlation are delineated. Considerable differences were seen, in some laboratories, depending on whether material G was or was not excluded on the reference eye test. For example, laboratories 2 and 31 lacked significant correlation when G was included, but correlated very well without G. While many laboratories on the eye test lacked significant correlation of relative sample irritation with overall irritation ranking; fewer did on the skin test. It is notable that, without G, laboratories 14and 31 had good correlation using the reference eye procedure but lacked significant correlation using their nonreference eye tests. Similarly, laboratory 31 correlated well on the reference but not on the nonreference skin test. The intercorrelations of reference with nonreference tests within each laboratory will be further discussed later. For laboratory 31, however, their nonreference eye and skin tests were considerably different from the reference procedures. Different volumes were used on the eyes in the nonreference procedures, irritation was recorded after uncovered application on the skin, and different grading systems were used for both tests.TABLE 42
SKIN-SCORE OF REFERENCEMETHOD(WITHOUT SCORE FORNECROSIS) ii

Laboratory No. E F G

13 3.4” 6.0” 2.2” 31 1.9 3.4” 1.9” 10 0.9 4.0” 1.4 14 2.9 4.1” 1.9 23 0.4 6.4” 0.4 25 1.8” 4.9” 0.6 7 1.8 2.1 0.0 11 3.1 5.4” 1.2 22 0.4 2.9“ 0.4 2 3.8 3.9” 0.2 12 1.1 6.9” 2.1 18 0.1 0.5 0.0 19 2.6 3.8 0.8” 30 0.4 1.6 0.1

4 0.7 2.3 0.1 5 2.8 3.8 1.1 8 1.9 4.6 0.8 9 1.5 6.9 2.6 24 1.2 3.9 0.5 26 1.2 4.9 2.5 27 0.1 4.0 0.1 21 0.0 0.0 0.0 No. of Material samples

~~~ ___~~ ~~
__ __~~
__ with I J K L M N 0 necrosis

3.7” 4.6” 5.6” 7.2” 1.0 2.6” 2.6” 2.0” 1.9 2.9” 4.1 4.8” 1.2 4.1” 3.8” 5.0” 2.1 4.7” 5.2’ 7.2” 0.4 2.9” 3.0 4.9” 1.8” 1.4” 1.9” 1.8” 0.8 4.4” 4.1 6.8” 0.7 2.1” 2.4” 2.6” 0.0 2.1 3.2 1.9” 2.0 4.2 5.2 7.9” 0.0 1.1 1.6” 2.4” 1.2 2.1 2.7 4.1” 0.6“ 2.6 2.5 3.8”
Laboratories that scored no necrosis



### - - 0.8 2.4 3.4 6.1 1.5 0.1 0.0 1.2 3.1 3.6 5.4 2.0 1.2 1.1 0.8 2.9 2.4 3.7 0.6 0.0 0.3 0.3 5.2 5.4 7.9 1.1 0.0 1.2 0.8 2.9 2.8 4.8 1.2 0.8 1.4 1.9 0.8 4.2 4.2 3.3 2.2 1.8 0.2 1.9 2.0 5.0 0.8 0.0 0.6 0.0 0.0 0.0 0.0 0.4 0.0 0.0 0.4 0.0 0.6” 8 0.5” 0.0 0.2 6 1.9” 1.1” 1.1 5 4.2” 3.1 2.5 5 1.1” 0.1 0.6 5 2.8“ 1.4 1.3 5 0.5 0.6 0.6 4 4.8” 1.8 3.4 4 0.2 0.1 0.1 4 0.9” 0.2 0.3 3 6.9” 3.2 4.9 3 1.2” 0.2 1.2 3 1.1 0.6 0.4 2 0.3 0.1 1.0 2

aNecrosis had been scored on this sample in this laboratory.TABLE 43
SKIN-RANKS AND SUMSOF RANKS OF PRIMARYIRRITATION SCORES(WITH NECROSISSCORE)

Laboratory Material

No. E F G I J K L M

2 2 3 16 21 17.5 14 10 7.5 4 16 18 18 13.5 16 13 14 12 5 5 16.5 9.5 8 12 12 15 11 7 10 19 21 2 9.5 11 17 18 8 8.5 13 11 13.5 13.5 19 21 17 9 11 11 3 18 6 6 12 14.5 10 15 6 7 5.5 11 9.5 3.5 4 11 3 8 8 13.5 5 9.5 7 2 12 14 1 5 4 9.5 7 1 1 13 1 4 2 1 4 3 3.5 19.5 14 4 10 6 8 3 5 9 3 18 20.5 21 21 21 20 20 13 10 19 6 16.5 9.5 8 17.5 17 11 14.5 21 22 22 21 21 22 22 22 19.5 22 18 9 14.5 16 7 4 5.5 22 23 18 7 14.5 3 2 1 8 9 24 12.5 15 13 13.5 13.5 16 18 13 25 7 5 12 17 1 15 2 5 26 12.5 12 4 5.5 21 8 20 7.5 27 20.5 14 18 19 19 21 16 16 30 18 20 18 11 15 18 19 21 31 8.5 2 1 10 8 2 5.5 6 N 0 Sum of ranks

11.5 17.5 120.0 14.5 21.5 156.5 7 9.5 105.5 9.5 14 131.0 19.5 17.5 153.5 19.5 7.5 108.5 3 9.5 74.0 5 2 63.0 1 1 44.5” 19.5 12 69.5 2 3 53.0” 11.5 7.5 165.5 9.5 16 125.5 19.5 21.5 212.5” 14.5 20 130.5 14.5 14 91.0 8 5 127.5 6 6 76.0 4 4 98.5 19.5 14 177.0” 14.5 11 165.5 19.5 19 81.5

aOutside limits; CQ.,,~

= 55.1 to 174.9.

### TABLE 44 E P SKIN-RANKS AND SUMS OF RANKS OF PRIMARY IRRITATION SCORES(WITHOUT SCORE FOR NECROSIS)



### Laboratory No.

13 2 4 3 1 3 

### 1 31 7.5 16 5.5 

### 10 12.5 15 10 

### 15 10.5 7 4.5 9.5 6.5 14 4 9 5.5 8 6 8 23 18 3 14.5 2 2 3.5 25 9.5 6.5 12 17 9.5 12 7 9.5 19 21 6 19 20 

### 11 3 5 8 12.5 4 6.5 22 18 17 14.5 15 16 17.5 2 

### 1 12.5 16 21 16 

### 11 12 

### 14 1.5 4 3 5 3.5 

### 18 20.5 21 21 21 20 21 19 6 14.5 10.5 8 16 14 30 18 20 18 16 12.5 16



### E F G I

-__ 4 16 

### 18 5 5 14.5 8 7.5 8 9 

### 11 1.5 24 12.5 12.5 26 12.5 6.5 27 20.5 10.5 21 22 22 

### Material Sumof No. of samples with 

### J K

10 5

21 17.5 5 2 17 19.5 20 14 1.5 1 18 9.5 14 12 

### L M N

3.5 19.5 19.5 19 17.5 19.5 11.5 7 7 8.5 3 2 3.5 12 14.5 5 9.5 4 14.5 11.5 

### 1 11.5 9.5 15 22 14.5 

### Laboratoriesthat scorednonecrosis

18 12.5 14 

### 10 6 8 14.5 21.5 138.5 9 8 7 9 7 6 6 9.5 81.0 10.5 12.5 9.5 17.5 16 16 19.5 17.5 134.5 1 18 

### 1 2 1.5 12 19.5 7.5 75.0 13 12.5 9.5 13 11.5 9.5 8 5 107.0 2 4.5 21 5 13 4 3 4 75.5 18 19 

### 18 19 8.5 15 19.5 13.5 161.5 21 21 22 22 22 21 19.5 21.5 214.0" 0 

### ranks necrosis

13.5 70.0 8 19 141.5 6 9.5 88.0 5 3 57.0 5 13.5 86.5 5 6 92.5 5 13.5 156.0 4 2 52.0" 4 20 169.0 4 17.5 140.5 3 

### 1 35.5" 3 7.5 171.0 3 16 120.5 2 

### 11 163.0 2



### uOutside limits;q,,05

= 55.1 to 174.9.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 325

TABLE 45
SIGNIFICANT AND NEAR-SIGNIFICANT SUMS OF RANKS FOR RANGE-SKIN REFERENCE TESTY Primary irritation scores Laboratory No. Range Including Excluding No. of samples necrosis component necrosis component with necrosis
13 53.0b 8 14 64.0 53.0b 57.0 5 12 64.5 44.5” 35.5b 3 11 65.0 63.0 52.0b 4
22 169.0 4 18 165.5 171.0 3 30 165.5 2 27 177.0b 0 21 204.5b 212.5b 214.0b 0
’ Near-significant = within 10 points of pertinent 95% limits listed. bq.05 limits = 55.1 to 174.9. TABLE 46
COMPARISON OF RANKS WITH AND WITHOUT NECROSIS-REFERENCE SKIN TEST
Laboratory No. of Sum of ranks

~ Relative rank of lab
No. and samples with With Without With Without type”qb necrosis necrosis necrosis necrosis necrosis .._~~ .~ 12T 14c 111 13T 1oc 251 311 23T 26G 5c 91 2G 19c 24T 22c 71 8T 4c 18C 3oc 271 21G 3 44.5’ 35.5’ 1 1

5 53.0” 57.0 2 3 4 63.0 52.0” 3 7 8 69.5 70.0 4 i 5 74.0 88.0 5 9 5 76.0 92.5 6 10 6 81.5 141.5 7 16 5 91.0 86.5 8 8 0 98.5 75.5 9 6 0 105.5 81.0 10 7 0 108.5 75.0 11 5 3 120.0 140.5 12 15 2 125.5 120.5 13 12 0 127.5 107.0 14 11 4 130.5 169.0 15 20 4 131.0 156.0 16 17 0 153.5 134.5 17 13 0 156.5 138.5 18 14 3 165.5 171.0 19.5 21 2 165.5 163.0 19.5 19 0 177.0” 161.5 21 18 0 212.5” 214.0’ 22 22
Coefficient of rank correlation - Concordance 0.882 0.855 4.67 5.24 - ’ Laboratories ordered by sum of ranks for primary irritation asin Table 47. bSeeTable 1. cOutside limits; ~~~~~= 55.1 to 174.9.

### TABLE 47 

## K m
SKIN REFERENCEMETHOD PARAMETERS 

### Laboratory Sum No. and of type” rank? Q2

Median rank Ql Q3
12T 14c 111 13T 44.5’ 2.5 1.0 7.6

53.0” 4.5 3.0 8.2 63.0 6.0 2.8 8.4 69.5 3.8 1.8 13.9 Semiinterquartile range,SIQR Range
3.3 1to 14 2.6 2to 10 2.8 2to 13.5 6.0 1to 19.5

1oc 74.0 6.5 3.4 9.9 3.2 3to 15 251 76.0 6.0 4.2 12.8 4.3 1to17 311 81.5 7.0 2.0 12.2 5.1 1to 19.5

23T 91.0 8.5 2.8 14.5 26G 98.5 7.8 4.0 14.4 5c 105.5 10.2 7.8 12.8 91 108.5 11.0 6.0 15.4 2G 120.0 12.2 6.4 17.5 19c 125.5 12.8 9.1 16.6 24T 127.5 13.2 11.4 15.2 22c 130.5 14.5 6.6 18.5 71 131.0 12.5 9.5 18.8 8T 153.5 15.2 13.5 19.1 4c 156.5 15.2 13.4 18.0 18C 165.5 20.0 11.1 21.0 3oc 165.5 18.0 13.6 19.2 271 177.0” 18.5 15.5 19.8 21G 212.5” 21.8 20.6 22.0 5.8 1to 18 5.2 4to 21 2.5 5to 16.5 4.7 3to 19.5 5.6 2to 21 3.8 6to 17.5 1.9 5to 18 6.0 4to 22 4.6 2to 21 2.8 8.5to 21 2.3 12to 21.5 5.0 7.5to 21 2.8 11to 21 2.2 14to21 0.7 19.5

to 22 Unusualfeatures No. of 10 samples with necrosis
5of 10ranked 1

7of 10ranked4or less; outsiders = M, N + 0

8of 10ranked10orless; outsiders = N + 0

6of 8ranked20ormore

10of 12--noreaction 5 6 E

E 5 None None None x 3 E 2 None 4 4 None None 3 2

None
’See Table1. b Based onprimaryirritationscores withnecrosis. ‘Outsidelimits;aa.os

=55.1to 174.9.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 327

i-T--1--~ T-T--I I I I I I I I I 1

FIRST QUARTILE Q2 SECOND QUARTILE
THIRD QUARTILE

I SKIN

lc---------ao o5 FiD”ClAL LlMITS - I I I I I I I I I III I I I I I I I 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 SUM OF RANKS FIG. 2. Sum of ranks, median, and variability-Skin reference procedure.

TABLE 48
COMPARISON OF SEMI-INTERQUARTILE RANGE (SIQR) OF REFERENCE EYE AND SKIN TESTS SIQR Rank of SIQR Laboratory Eye Skin Eye Skin No. test test test test
21 9.2 0.7 1 21
7 7.2 4.6 2 8 2 6.2 5.6 3 4 25 5.5 4.3 4 9 8 5.2 2.8 5 14 10 4.9 3.2 6 12 19 4.8 3.8 7 10 11 3.9 2.8 8 14 5 3.8 2.5 9.5 17 23 3.8 5.8 9.5 3 18 3.6 5.0 11 6 13 3.4 6.0 12.5 1.5 24 3.4 1.9 12.5 20 31 3.1 5.1 14 5 27 3.0 2.2 15 19 30 2.8 2.8 16 14 9 1.9 4.7 17 7 12 1.5 3.3 18.5 11 14 1.5 2.6 18.5 16 22 1.4 6.0 20 1.5 4 1.2 2.3 21 18 Coefficient of rank correlation +0.00033

### 328 WEIL AND SCALA



### Laboratories 21 and 26, both governmental laboratories, also lacked significant correlation on their nonreference skin procedures with the overall, all-laboratory, sample ranking by the reference procedure. The reference procedure results of laboratory 21 have been previously discussed in some detail. Laboratory 26, like laboratory 31, discussed above, used uncovered skin and a different scoring system while the nonreference procedure of laboratory 21 was quite similar to the reference test.

TABLE 49 EYE-INTRALABORATORY SAMPLE RANK-L%-HR MEDIAN-REFERENCE METHOD



### Laboratory --~ No. A
-__ 1 2 4 

### 5 I 8 9 

### 10 11 12 13 14 16 18 19 21 22 23 24 25 27 29 30 31 2 3 

### 1 6 8 5 7 9 4

7 3 9 4 8 1 2 5 6 8 3 9 5 1 6.5 2 6.5 4 9 3 1.5 1.5 6.5 6.5 6.5 6.5 4 3 2 

### 1 5 4 6 7.5 7.5 9 9 5.5 1 2 8 7 4 5.5 3 

### 5.5 5.5 1 2.5 8 4 2.5 7 9 8 4 2 6 9 1 3 5 7 8 7 

### 1 5 9 2.5 2.5 4 6 7.5 5 1 6 9 2 3 7.5 4 2 6 1 9 7.5 7.5 4 4 4 7 

### I 6 3.5 9 3.5 2 5 8 2.5 6 1 5 4 2.5 7 9 8 2 3.5 1 6 8 7 3.5 9 5 9 6 1 5 2.5 4 7 2.5 8 6 2 3 1 5 4 7.5 7.5 9 8 1 7 4 9 3 2 5.5 5.5 7 4 

### 1 2 8 3 5 9 6 5.5 8 

### 1 2 7 3.5 3.5 5.5 9 2 5 1 6 9 3 4 8 7 5 2.5 1 7 8 4 2.5 9 6 3 2 1 5 6 4 7.5 7.5 9 8 1.5 6 4.5 4.5 3 7 1.5 9 5 4 6.5 6.5 8 2 

### 1 3 9


### Sumof ranks F G J Material

K

139 93.5 65” 109.5 166” 

### L

___
95.5 

### M N 

### P

-

103.5 149.5 158.5

a Outside limits; Q,.,J~ = 80.5 to 159.5.



### E. NonreferenceversusReferenceProcedures In the previous section, comparisonsweremadeof differencesin somelaboratories betweenranking the severity of irritation of thepertinent samples by the reference(R)
or nonreference (NR) procedure and the overall rank of all laboratories of these materials by the reference procedure. In this section, comparisons will be made between R and NR in each laboratory where both procedures were run. TheseINTERLABORATORY EYE AND SKIN COMPARISONS 

### 329

correlations for each such laboratory are presented in Tables 56 and 57for the eye and skin tests, respectively. As in Table 54, the nonsignificant correlations are delineated, i.e., those where the rank coefficients of correlation were not different from zero.

TABLE 50

EYE-INTRALABORATORY SAMPLE RANK-MEDIAN OF MEDIANSREFERENCE METHOD



### Laboratorv Material

No. - A F G J K L M N P



### 1 7 2 

### 1 5 8 3 6 9 4 

### 2 6.5 

### 1 8 2 5 3 4 6.5 9 4 5 2 9 6 

### 1 4 3 7 8 5 9 8 4 2 

### 1 3 5 6 7 7 3 2 

### 1 5 4 6 7 9 8 8 9 3 

### 1 2 6 4 5 7 8 9 5 3 

### 1 4 6 2 7 8 9 10 7 5 4 3 8 1 2 6 9 I1 7 5 

### 1 2 8 3 4 6 9 12 9 2 3 5 8 

### 1 4 6 7 13 7 2 

### 1 6 9 8 3 4 5 14 8 3 5 

### 1 9 2 4 6 7 16 5.5 4 

### 1 5.5 2 3 7 9 8 18 7 

### 1 3 2 4.5 4.5 6 9 8 19 9 4.5 

### 1 4.5 3 2 7 6 8 21 5 2 

### 1 3 6.5 4 6.5 8 9 22 9 

### 1 7 3 8 6 2 5 4 23 5 4 

### 1 3 6 2 8 9 7 24 2 5 1 3.5 3.5 7.5 6 7.5 9 25 5 6 

### 1 4 8 2 3 9 7 27 4 3 

### 1 9 6 2 5 8 7 29 6 2 

### 1 3 5 4 8 7 9 30 8 3.5 6 

### 1 2 5 7 3.5 9 31 7 3 6 5 4 2 

### 1 9 8

Sum 

### of ranks 155 77” 69" 89.5 131.5 84 120.5 170.5" 183"



### ’ Outside limits;~~~~~

= 80.5 to 159.5.

The correlations werealmostall significant onthe eyeandtheskinproceduresusing 12samples,

ratherthan the9or 10pertinent ones usedinall ofthepreviousdiscussions. Thus, theinclusion of thedata on materialsE, I, and 0 for the eyeand onA and Pfor the skin testsgenerally decreaseddiscrimination betweenreferenceand nonreference proceduresin the laboratories. The 2 and 1nonsignificant correlations, usingall 12 materialsfor eyeand skin comparisons,will not befurther discussed, asmost of the
samelaboratories still had nonsignificant correlations when the data for the lowdifferentiating materialswereremoved.

### 330 WEIL AND SCALA

TABLE 51
EYE-INTRALABORATORY SAMPLE RANK-MEDIAN OF MEDIANS-NONREFERENCE METHOD
Laboratory ____- No.
-_ ._ 1 4 5 7 8 9 10 11 13 14 16 22 24 27 30 31”
___- Sum of ranks 

### - A F G J Material
-____ K L M N P
5.5 2 1 6 2.5 9 9 7 3 8.5 1.5 8.5 9 2 1 5 3 1 5 3 1 9 1 7 8 7 9 8.5 2 5.5 5 2 1 8 4 5 3 4 1 8 3 1 8 5 7 5 1 7 7 4 2 3 6.5 4 7 3 2 5.5 3 3 2 4 4 6 8

1 1 1.5 5 7 8 8 3 8.5 6 2 5 6 3 8

__. ~__ 3.5 5.5

7 2.5 4 5 4 6 4 6.5 2 6 2 4 2 4 1 4 5.5 2 4 7 1 6 6 8 2 5 2 1 4 2 9

5 6 6 8 8 6 6 5 2 9 7 7 9 6 3

-~ 3.5

8 8 6 3 9 9 5 6 5.5 8 9 9 7 9 9

110.5b 50* 68 66 81 54b 74.5 102 114b

a Read only at 24 hr. bOutside limits; CQ.,,~ = 58.9 to 110.1.
TABLE 52
SKIN-INTRALABORATORY SAMPLE RANK-REFERENCE METHOD
Laboratory No.

- 2 4 5 7 8 9 10 11 12 13 14 18 19 21 22 23 24 25 26 27 30 31 -E F

3 1 7 4 5 2 6 5 5 1 6 2 10 2 7 2 10 2 6 2 7 2.5 8 6 4 2 6 6 6.5 2 8.5 3 6.5 2 6 2 9 1 8.5 2 7 4 7 1 Material

G I J K L M N
8.5 10 6 5 2 4 8.5 8 6 3 2 1 5 9 9.5 7.5 4 3 1 6 7.5 10 4 2 3 1 9 7.5 6.5 6.5 3 4 2 8 10 5 9 4 3 1 8 10 8 7 5 4 1 3 6 9 10 4 5 1 3 8 8 9 6 4 1 3 7 7 5 4 3 1 9 10 9 10 2.5 5 1 4 6 9.5 9.5 5 2 1 3 7 7.5 6 5 3 1 7.5 9 6 6 6 6 6 1 6 6.5 5 4 3 1 8 9.5 8.5 6 4 2 1 5 10 10 8.5 3 4 1 6.5 8.5 9 10 3 5 1 4 7 5 7 10 2.5 2.5 4 6 8.5 7 4 3 1 5 10 9.5 6 2 3 1 8 9.5 6 8 5 3 2 4 10 

### - 0

7 10 9.5 7.5 9 7 9 6 5 8 8 4 10 6 9.5 7 5 8 8 6 5 9
Sum of ranks 149 56.5” 174.5” 163” 94.5 77.5” 31.5” 118 182” 163.5”
’ Outside limits; OL,,.~~

= 79.4 to 162.4.1NTERLABORATORY EYE AND SKIN COMPARISONS 

### 331

On the basis of the 9 pertinent samples, the following laboratories lacked significant
or had negative correlation (Table 56) between their reference and their nonreference eye procedures :

Coefficient of rank correlation Nonreference

Type of _~__._--- test Draize or Laboratory laboratory 24-Hr basis Median of median basis FHSA type

5 C 0.388 Yes 7 I 0.046 0.042 Yes 8 

### T 0.415 0.579 Yes 

### 11 I 0.288 0.383 No 13 

### T -0.812 -0.617 Yes 14 C 0.529 Yes 22 C 0.188 0.000 Yes 24 

### T 0.542 Yes 30 C 0.392 0.462 Yes 31 

### I 0.433 No



### TABLE 53 SKIN-INTRALABORATORY SAMPLE RANK-NONREFERENCE METHOD



### Laboratorv Material

No. ” E F G I J K L M N 0

4 9 2 8 4 5 3 

### 1 6 7 

### 10 5 6 2 

### 10 8 3 4 

### 1 5 7 9 7 5 1.5 

### 10 6 3 4 1.5 9 7 8 8 5 2 8 7 3 4 

### 1 6 9.5 9.5 9 8.5 2 7 5 4 3 

### 1 6 

### 10 8.5 10 9 2 

### 10 8 4 5 

### 1 3 6 7 11 6 3 9 4 5 2 

### 1 7 8 10 12 8 2.5 9 

### 10 2.5 5 2.5 2.5 6 7 13 

### 10 1 6 5 4 3 2 7 8 9 14 5 3 9 8 2 

### 1 4 7 

### 10 6 21 7 7 7 3 7 7 7 1.5 1.5 7 22 5 2 6.5 6.5 3 4 

### 1 8 9.5 9.5 23 8 1.5 10 9 5.5 3 1.5 4 7 5.5 24 5 2 9.5 7.5 3 4 

### 1 6 9.5 7.5 25" 6.5 2.5 8 6.5 4 5 

### 1 2.5 9.5 9.5 25b 10 1 9 7 5 6 3 2 4 8 26 4 6 2 6 8.5 

### 1 3 6 8.5 

### 10 3 21 6 

### 1 9 10 3 4 2 5 8 7

30 7 5 

### 10 7 3 4 

### 1 7 9 2 31 7.5 1.5 4 5.5 3 

### 1 2 9 

### 10 5.5 

### Sumof ranks 137.5 56.5‘ 161" 133 80.5 73 38.5' 109.5 155' 155.5'



### o Guinea pig-FHSA method

(21Code of Federal

Regulations). bGuinea pig-cuff method

(Roudabush

etal., 1965). cOutside limits;CQ,.~~

= 71.0 to 149.0.TABLE 54

CORRELATIONOF INDIVIDUAL LABORATORY RANKINGOF SAMPLES WITH OVERALL TNTRALABORATORY RANKOFSAMPLESEVERITYOFIRRITATION Eye test (with sample G) Eye test (without sample G) E

- ~__
____ Laboratory Reference Nonreference Reference Nonreference Skin test

-- -~___ No. and -~___- ___--.
__ 24-Hr Median of Median of 24-Hr Median of Median of Nontype” median medians medians median medians medians Reference reference

--. _. Coefficient of rank correlation of sample ranks for individual laboratories LX overall sample ranks IT 0.561b 0.733 0.392b 0.381b 0.619” 0.357b - - 2G 0.300b 0.512b - 0.857 0.970 - 0.803 4c -0.37gb 0.133b 0.221b -o.133b 0.61gb 0.423b 0.915 0.903 5c 0.471b 0.283b 0.417b 0.286b 0.214b 0.452b 0.933 0.952 71 0.529b 0.700 0.533b 0.327b 0.571b 0.696 0.724 0.852 8T 0.37gb 0.900 0.438b 0.113b 0.857 0.423’ 0.870 0.912 91 0.800 0.917 0.783 0.714 0.881 0.833 0.818 0.894 1oc 0.833 0.667 0.633 0.810 0.738 0.690 0.758 0.855 is 111 0.629 0.817 0.733 0.470b 0.738 0.833 0.842 0.915 12T 0.746 0.783 0.637b 0.762 P
- - 0.709 0.752 13T 0.204’ 0.383b 0.283’ -0.137b 0.119b 0.429b 0.855 0.806 5 14c 0.688 0.617 0.379b 0.934 0.690 0.411b 0.798 0.733 16T O.446b 0.746 0.733 0.208b 0.637b 0.762 - - 8 18C 0.588b 0.862 - 0.41 lb 0.899 - 0.652 - F 19c 0.188b 0.754 --0.161b 0.649 *

- - 0.882 21G 0.5796 0.929 - 0.518” 0.899 - 0.394b 0.015b 22c 0.546b 0.183b 0.767 0.899 0.429b 0.762 0.867 0.818 23T 0.800 0.800 - 0.714 0.714 - 0.936 0.836 24T 0.558b 0.483b 0.417b 0.36gb 0.262b 0.381b 0.885 0.915 251 0.767 0.717 - 0.667 o.595b - 0.855 0.894” 0.685d 26G - - - - - - 0.506b 0.276b 271 0.854 0.667 0.817 0.792 0.524b 0.881 0.936 0.842 29c 0.721 0.883 - 0.613b 0.833 - - 3oc 0.250b 0.327b 0.567b 0.429b 0.45Sb 0.643 0.827 0.600 311 0.454b 0.583b 0.500b 0.667 0.762 0.595b 0.903 0.364b NS: total No. of labse 15124 8124 lo/16 15124 11/24 8116 2122 3120

aSeeTable 1. hRank correlation coefficient nor significantly different from zero correlation. cGuinea pig-FHSA method (21 Code of Federal Regulations). dGuinea pig-cuff method (Roudabush at ol.. 1965). eNumber of laboratofies with nonsignificant correlations: total number of laboratories.TABLE 55
SUMMARY OF RESULTS OF INTRALABORATORY SAMPLE COMPARISONS

Material Eye test (with sample G) Eye test (without sample G)
Non- - Non- Skin test Reference reference Reference reference Skin test Eye test Rank for Rank for column column 24-Hr M,e,“dii‘,“,;f Ee$hn;f 24-Hr median median FeddiFl$f M,eeddsof Non- -___ Material Reference reference 1 2 3 4 5 6 7 8

Column 1 2 3 4 Sum of ranks 5 6 7 8 Sum of ranks

A’ 139.0 155.0 110.5b 118.0 F 93.5 77.0b 50.0b 76.5 G 65.0 69.0b 68.0 - J 109.5 89.5 66.0 92.5 K 166.00 131.5 81.0 145.0b L 95.5 84.0 54.0s 18.5 M 103.5 120.5 74.5 84.5 N 149.5 170.5b 102.0 131.5 Pa 158.5 183.0b 114.0b 137.5 133.0 61.0b 98.0

42.0b

- - 74.5 58.5 112.5 71.0 69.0b 45.5 102.5 65.5 150.5b 93.0 161.0* 102.5 EC F G J K L M N OC 1’ 149.0 137.5

56.5b 56.5’ 174.5” 161.0b 94.5 80.5 77.5b 73.0 31.5’ 38.5b 118.0 109.5 182.0b 155.0b 163.5b 155.5b 163.0b 133.0 No. of labOratOrieS 24 24 16 24 24 16 22 20 95 7: limits 80 to 160 80 to 160 59 to 110 73 to 143 73 to 143 45 to 99 79 to 163 71 to 149 6 7 8 5 6 7 221111 1 1 4--- 5 4 3 4 3 3 9 6 6 8 5 5 332222 455344 7 8 7 6 7 6 8 9 9 7 8 8 6 7 2 2 9 10 4 4 3 3 1 1 5 5 10 8 9 I: 6

nNot used as a pertinent material for skin test. b Outside 95 ‘A limits. cNot used as a pertinent material for eye test. Coefficient of rank correlation:
column 1 vs. 2 +0.883b column 1 vs. 3 +0.750* column 2 vs. 3 +0.883” column 7 vs. 8 +0.952b

### TABLE 56
EYE IRRITATION TESTS-SPEARMAN RANK COEFFICIENT OF CORRELATION 

### (17LABORATORIES WHICH RAN BOTHTHEREFERENCEAND ANONREFERENCETEST; 

### 24LABORATORIES RAN THE E P REFERENCETEST-9 OR 12 PERTINENT SAMPLES)


### Rankcoefficientof correlation
Nonreference

vs. Reference
Laboratory Reference median Reference median 24-Hrmedianvs. No. and at 24hr of medians medianofmedians Brief descriptionof type’ 9Samples 12Samples 9Samples 12Samples 9Samples 12Samples nonreference method
1T 0.842 0.970 0.942 0.960 0.733 0.881 Like ref. Usedslit-lamp 4c 0.800 0.911 0.846 0.928 0.712 0.879 Draize method; 3 to 4 kg. ? nonref.;
5C 0.388’ 0.741 0.967 0.981 0.28Sb 0.680 71 0.046b 0.2016 0.042b 0.27Sb 0.971 0.948 ST o.475b 0.736 0.579b 0.780 0.604 0.834 91 0.775 0.906 0.983 0.993 0.683 0.867 1oc 0.833 0.902 0.683 0.839 0.817 0.923 111 0.28Sb 0.694 0.383b 0.740 0.746 0.888

13T -0.812” -0.0336 -0.617” 0.131b 0.546b 0.808 14c 0.786 0.897 0.529b 0.797 0.829 0.928 16T 0.729 0.879 0.771 0.904 0.854 0.932 22c 0.188b 0.652 O.OOOb 0.580 0.879 0.942 24T 0.542b 0.801 0.892 0.955 0.483b 0.776 271 0.721 0.820 0.650 0.776 0.820 0.925 3oc 0.392” 0.687 0.462’ 0.670 0.745 0.864 311 0.879 0.948 0.433b 0.760 0.496b 0.788

21G 2G 12T 19c 18C 23T 2% 29c -

-

-

-

-

-

-

- -

-

-

-

-

-

-

- -

-

-

-

-

-

-

- -

-

-

-

-

-

- 0.896 0.941

0.688 0.839 0.746 0.893 0.842 0.892 0.292h 0.687 0.833 0.930 0.850 0.937 0.879 0.949 2to 3kg. $ ref.

FHSA (21Codeof FederalRegulations) FHSA Like ref.; meanscoreof 7daily readings. Like reference Like reference Twodrops.Washed

ornonwashed,

30sec. Different scoringsystem FHSA Like reference Not readafter72hr. Different Draizeindex Draizemethod OrginalDraize. Eyesheldclosed 5set 1959 “Appraisal” Draizemethod FHSA Different volumes

tested. 24-hrreading

only. Different scoringsystem

-

-

-TABLE 56-cotztittued

Rank coefficient of correlation

Reference 2 Nonreference vs. s 24-Hr median us. 5 Reference median at 24 hr Reference median of medians median of medians 5

- -~ 9 Samples 12 Samples 9 Samples 12 Samples 9 Samples 12 Samples 3

~ % 25th Percentile Q’ 0.338 0.690 0.408 0.705 0.644 0.836 u Median Qz 0.642 0.810 0.614 0.788 0.746 0.890 E 75th Percentile Q3 0.793 0.904 0.869 0.942 0.846 0.931 52
ao.05 0.600 0.506 8 ao.01 0.783 0.712 6

R SeeTable 1. bCorrelation not significantly different from zero correlation (P > 0.05). ’ Significant negative correlation (P < 0.05).

### 336 WEIL AND SCALA



### TABLE 57

SKIN IRRITATION TESTS; SPEARMAN RANK COEFFICIENT OF CORRELATION 

### (19 LABORATORIES WHICH RAN BOTH THE REFERENCE AND A NONREFERENCE



### TEST-10 OR 

### 12 PERTINENT SAMPLES)



### Rank coefficient Laboratory of correlation No. and ~ type” 10Samples 12Samples Brief description of nonreference test

4c

5C 0.970 0.895

71 0.879 0.930 8T 0.945 0.955 91 0.803 0.869

1oc 0.927 0.918 111 0.515’ 0.580

12T 0.836 0.885 13T 0.830 0.746 14c 0.621 0.710

21G 0.779 0.712 FHSA. Covered with parafilm and adhesive tape and

22c 0.961 0.948 23T 0.821 0.836

24T 251

26G 271 3oc 311

25th Percentile Ql Median Qz 75th Percentile Qs

a0.05

a0.01 

### 0.867 0.918

0.933 0.928 0.845 0.691 0.709 0.743 0.521’ 0.701 0.852 0.895 0.912 0.932 0.406’ 0.502’

0.744

0.840 0.877 0.920 0.923

0.564 0.506 0.746 0.712 FHSAb test using 93 to 4 kg; intact and abraded;

reference $2 to 3kg “Appraisal of Safety of Chem.“-Draize (1959) method. Abraded; no plastic cover. FHSA Rubberized cloth cover; skin rinsed after cover removed FHSA intact and abraded. Elastoplast and filter cloth cover-snug FHSA 10 repeated applications over 14 days; cotton pad; different scoring system Abraded, covered with Elastoplast. Similar to FHSA FHSA grading but not covered-no sleeve Draize (1944). Abraded and nonabraded; polyethylene cover

rubber dam. Read at 24 hr FHSA Abraded; tape, SARAN, then masking tape-snug, more occluded Practically identical to reference procedure Guinea pig-FHSA method Guinea pig-cuff method No cover; different scoring system Like lab 5 FHSA 0.01ml uncovered; read at 24hr only; different scoring system

0.711

aSeeTable 1. bFHSA method (21 Codeof Federal Regulations). cCorrelation not significantly different from zerocorrelation (P > 0.05).INTERLABORATORY EYE AND SKIN COMPARISONS 

### 337

Thus 10 of the 16 laboratories which ran both the reference and nonreference procedures had some lack of significant correlation. In only 2 of these 10 was the nonreference procedure really different, in method of application and/or in scoring, from the reference procedure. Note that, while none of the 3 governmental laboratories is in the above list, none of them could have been. Two did not attempt a nonreference test (laboratories 2and 21) and one, laboratory 26, did not attempt either eye procedure. In all, 8 laboratories did not try anonreference test asseveral of them recognized the close similarity between the quantity of material applied and the scoring method of the reference procedure and of the Federal Hazardous Substances Act (FHSA) and the Draize methods. With this similarity in mind, it is, indeed, remarkable that 8laboratories, listed above, did not obtain a significant, positive, correlation in their own laboratory, between their nonreference (FHSA or Draize) and their reference procedures. Two of these 8(laboratories 7 and 22) had practically zero correlation, while laboratory 13 had negative correlation. The ranks, at 24 hr, of the 9 pertinent samples for these 3 laboratories
are repeated in the accompanying tabulation.

Laboratory 7 Laboratory 22 Laboratory 13
--__. -__

Non Non- NonSample Reference reference Reference reference Reference reference

A 3 8.5 8 F 2 1.5 1 G 1 8.5 7 J 5 3 4 K 4 1.5 9 L 6 4 3 M 7.5 6 2 N 7.5 6 5.5 P 9 6 5.5 2 6 I 9 7.5 7.5 4 4 4

Coefficient of correlation : With G 0.046 Without G 0.464 0.188 -0.812 0.220 -0.732

The lack of correlation was not associated entirely with sample G, an inconsistent sample between laboratories, although it is remarkable that this could have been ranked most irritating by the reference tests in laboratories 7and 13and least irritating by their nonreference, practically identical, procedures. For the skin, reference Z)USUSnonreference procedures in the same laboratories, attempted by 19 laboratories, only 3 had nonsignificant correlations. This is not unexpected, as the nonreference procedure in most laboratories was the FHSA or Draize procedure. The laboratories with nonsignificant correlations were 11, 26, and 31. Laboratories 26 and 31 used uncovered application, laboratory 11 used 10 repeated applications, and all 3had different scoring systems from the reference or from FHSA.

### 338 WEIL AND SCALA



### Laboratory 13 used FHSA grading, but no cover, and laboratory 25 used two procedures, both with guinea pigs instead of rabbits. In these, as well as in the laboratories other than 11, 26, and 3I, the good correlation indicated the close similarity between results of the FHSA and the reference procedures, even though no necrosis was scored
on the former and no abrasions were used on the latter. This being true, it is, indeed, remarkable how some of these same laboratories were outliers when compared by the reference procedure to the other laboratories, as previously described.

F, Degree of Irritation The results of the laboratories were compared to determine the degree of homogeneity that they would obtain in rating the tested materials as “irritants” or “nonirritants.” The definitions used for this designation were those of regulations under the FHSA Code of FederaI Regulations: for the eye test the number of rabbit eyes with “positive” scores and for the skin test a primary irritation index of 5.0 or higher. The degree-of-irritation ratings on the eye test, in 24 laboratories, are presented in Table 58.The nonreference procedure results (Draize-type tests) were used in 16laboratories and the reference procedure only in 8. In 8 laboratories the personnel presented their own irritancy ratings, and these were used. In the other 16, the laboratories presented no degree-of-irritancy rating; therefore, one of the authors rated the recorded readings of the individual rabbits as “positive” or “negative.” The degree-of-irritancy ratings on the skin test are presented in Table 59. As the reference procedure did not involve abrasion of one-half of the patch areas, only the results of the laboratories which used the FHSA test as their nonreference procedure could be used. In both Tables 58 and 59, the ratings of the materials which were not used in the preceding sections of this report, the low-discriminatory materials, are listed. The frequencies of nonirritant, questionable, or irritant ratings for the eyetest and of the degree of nonirritancy or irritancy for the skin test are summarized for all materials in Table 60. On the eye, only one material, B, was rated the same, nonirritant, in all laboratories. However, on the skin, 4 of the 6 low-discriminatory materials (A, B, D, and H) were consistently rated nonirritating. It is notable that this all-or-none word classification can be determined quite differently in different laboratories. Material N on the eyes was rated nonirritant or questionable by 7, but was rated an irritant by 17laboratories; material 0 was rated an irritant by 6of the 24laboratories. On the skin, material Fwas rated A or B (nonirritant) by 8, and C by 8 laboratories, a 50: 50 division in ranking as an irritant or not. Material L was classified C (a skin irritant with ascore above 5) by 1I laboratories, but classified nonirritating (A or B) by 5laboratories. Similarly, K was rated an eye-irritant by 21 but
a nonirritant by 3 laboratories. Obviously, therefore, as noted in the previous, more quantitative discussions of the reference-procedure results, the current FHSA eye and skin tests, as used by avariety of laboratories, often did not give similar results. Thus the use of this type of irritant or nonirritant category designation, using word-descriptions that have existed for years (Draize ratings for eye or skin irritation), can be quite unreliable.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 339TABLE 59
DEGREE-OF-IRRITATION RATINGS-SKIN TEST

LaboraMaterial
tory E No.“ F G I J K L M N 0 A B Degree-of-irritation rating on nonreference test (FHSA)b

4 A B A B 5 B B A A 7 A B A A 8 A B A A 9 A C B B 10 A B A A 12 B C B B 13 A B A B 14 B C A A 21 A A A B 22 A C A A 23 B C A A 24 B C A A 25 A C A B 27 A C A A 30 A A A A C D

B B C A A A A A B B B B A A A A B A A 2 A A B B B A A A A A C C C B A A A A B B B A A A
c c c : C B A A
c c c B A A A
c c c : A A A A A A A B B A A A C B C A A A A A B B C B B B A A B B C A A A A A B B C C C A A A B B C A A A A B B C A A B A A A

A A A A A A

A A A A A A B A A A A A A A A A A A A A

aReference testonly run bylaboratories 2, 18,and 19.Nonreference testwas not similar to FHSA procedure in laboratories I I, 26, and 31.
Terms used bylaboratories bA = combined average of2.0 or lower or negative or mild B = combined average of2.1 to 4.9 or moderate
- 

### -

C = combined average of5.0 or higher or severe or strong (primary irritant by FHSA definition). P

A A A A A Q
B s B % A u A w A A % A A A A A

### TABLE 60

FREQUENCY THAT MATERIALS WERE RATED AS EYE OR SKIN IRRITANTS



### Eye

Material Code Non- Questionirritant (Nl) able Irritant (I)

95% Ethanol Isopropyl myristate Triethanolamine lauryl sulfate; 46% aqueous Peroxide; 20 vol cream Triethanolamine Ethoxylated lauryl alcohol Decaethoxy oleyl ether Linoleic diethanolamide n-Butyl alcohol Methyl ethyl ketone Methyl isobutyl ketone Ethylene glycol monoethyl ether Propylene glycol 2% Formaldehyde Glycerin Aluminum chlorhydroxide; 50% aq. A 3 2 19 E 22 2 0 F 1 

### 0 23
G I J K L M N 0 P

z D H 0 I 23

18 

### 3 3 4 2 18 3 0 21 1 1 

### 22 2 2 20 4 3 17 14 4 6 3 2 19 20 0 0 18 1 1 

### 19 1 0 15 4 0 Skin

- Minimum” percentage of A B C laboratories which would label sample as an irritant 4 2.1to 4.9 25 NI NI I Eye Skin

16 0 0 79 0 11 

### 5 0 0 0 2 6 8 96 50

14 2 0 96 0 10 

### 6 0 12 0 2 9 5 75 31 2 10 

### 4 88 25
1 

### 4 I1 

### 92 69 7 6 3 83 19 11 

### 3 2 71 12 13 3 0 25 0 13 3 0 79 0 14 0 0 0 0 13 1 

### 0 4 0 14 0 0 0 0 14 0 0 0 0

n Minimum, since “questionable” is rated here as nonirritant.

### 342 WEIL AND SCALA



### G. Comparison of Eye and Skin Rating in the Same Laboratories It is of interest to compare the laboratories that performed both the reference eye and skin tests to determine whether laboratories that ranked relatively high on the one also tended to rank high on the other. The relative ranks on both tests are presented in Table 61. The coefficient of rank correlation, for the 21 laboratories which performed both tests, was +0.544, statistically significantly different from zero correlation. Some laboratories, therefore, which ranked low (a small rank number indicates relatively
severe readings) on the eyetest (e.g., laboratory 12ranked 2) also ranked low on the skin test (laboratory 12 here ranked l-the most severe reading). Laboratory 27, contrariwise, ranked 20th of 21 laboratories on both the eye and skin test.

TABLE 61

COMPARISON OF RELATIVE RANK OF LABORATORIES

ON BOTH THE EYE AND SKIN TESTS



### Relative rank” Relative ranksb if both eye and skin tests were run Laboratory No. Symbol Eye test Skin test Eye test Skin test

4 C 2” 18 1 17 12 

### T 3” 1’ 2 1 14 C 4” 2” 3 2 10 C 6 5 4 5 31 

### I I 7 5 7 22 C 8 15 6 14 2 G 9 12 7 11 9 

### I 10 11 8 10 

### 11 I 11 3 9 3 23 T 12 8 10 8 25 

### I 13 6 11 6 

### 21 G 14 22” 12 21 

### 5 C 15 10 13 9 19 C 16 13 14 12 24 

### T 18 14 15 13 7 

### I 19 16 16 

### 15 13 

### T 20 4 17 4 18 C 21 19.5 18 18.5 8 

### T 22 17 19 16 27 

### I 23” 21’ 20 20 30 C 24” 19.5 21 18.5

29 C 1C 1 

### T 5 16 

### T 17 26 G - -

- - -

- - 9 --

(I Rank of 1 assigned to the laboratory with the smallest sum of ranks; rank of 1 (for each material) assigned to the laboratory with the highest (most severe) score. b Coefficient of rank correlation = +0.544; 0.01 > P > 0.001.
cP < 0.05 for sum of ranks in interlaboratory comparison of reference method.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 343

In 4laboratories, there was aconsiderable difference in the relative rank in the eyeand skin tests :

Relative rank
Laboratory Eye test Skin test

4 1 17 22 6 14 21 12 21 13 17 4



### If theresultsofthese4laboratories hadbeenomitted, andtheremaining 17reranked, thecorrelation coefficient would havebeenraisedfrom +0.544to+0.899, aconsiderable increase.However, it isnotable that, whilethemajority of laboratoriesthat readrelative highscores

onthe onetestalsotendedto readhighontheother, thiswasnot universally true. The scores

recordedfor thelow-differentiating materialsarepresentedinTable62.

TABLE 62
SCORES RECORDED FOR LOW-DIFFERENTIATING MATERIALS ON REFERENCE TESTS
Material designation 

### Laboratory B C D E H I 0 A BCDHP No. -_

Eye test-24-hr median Skin test
-___ 1 2 4 5 7 8 9 10 11 12 13 14 16 18 19 21 22 23 24 25 26 27 29 30 31 1 622928

0 200732 0002256

--- 6 -- 6 18 0 0 0 5 0 10 1 0000203 0000201

--- 7- 4 3

--- 2- 2 2 0 2 2 2 3 6 26 0000112 0 0 0 0 2 3 24 0000123 0 14 1 0 6 0 6

--- O- 6 7 0000243 0 1 0 2 2 6 3 0 1 0 1 4 2 0 0000235 2 0 1 o- 2 2

----__ -ioooooo 0000062 1 0 1 0 4 8 5 0000006 

### - 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0

- 0.0 0.4 0.0 0.0 0.1 0.0 0.4 0.0 0.0

- 0.0 1.0 

### - - - 0.0 0.0 0.0 0.1 0.0 0.1 

### -

0.0 0.0

0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.2 

### -

0.0 0.0 0.0

- - - 

### - 0.2 0.4 0.4 0.2 1.3 0.0 0.0 0.4 0.0 0.0 0.0 2.4 0.0 0.1 0.0 0.0

- - - 0.0 0.0 0.0

0.0 0.0 0.0 0.4 0.0 0.0 0.5 0.2 0.2 0.5 0.0 0.2 0.9 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0

0.0 0.0 0.0 0.8 0.0 0.0 - 0.1

- 0.0 0.1 0.0 0.0 0.0 0.0 0.1

- 0.2 0.0 

### 0.1 0.0 1.0 0.6 0.2 0.3 0.7 1.5 2.6 1.1 2.1

- 0.2 0.4 0.0 0.0 0.1 0.0 1.0 1.0 0.0

- 0.6 0.0

### 344 WEIL AND SCALA



### H. Retest, Using Reference Procedures, in Two Laboratories Two laboratories were arbitrarily selected and graciously agreed to rerun the reference eye and skin tests under the following conditions: 1. Aliquots of the same samples of the materials used in the first run were tested for microbial content, and, found negative, were then used in the rerun. 2. An independent observer (“0”; one of the Steering Committee) participated in the retest in both laboratories. 3. The skins of the rabbits selected for use were clipped the day before application of the materials and were assigned by randomization into 2groups. An investigator (I) in each laboratory (the same one who ran the first test, if possible) treated his rabbits just prior to the time the independent observer treated his. 0 observed the investigator, but made no comment at the time on his technique. Then 0 treated his rabbits. The I at each laboratory treated 12 and 0 treated 12 other rabbits as follows:

a. Eye test 1. The reference procedure was used. 2. I treated 4eyes (2 right and 2left) per sample, using materials F, J, K, L, M, and N. 3. 0 also treated 4 eyes (2 right and 2left) per sample, using the same materials. 4. The next day, approximately 18 to 24 hr post-treatment, I read, graded, and recorded the results of the rabbits he treated, and 0 read, graded, and recorded the results of his treated rabbits. Then 0 read, graded, and recorded the Itreated rabbits and I read, graded, and recorded the results of the O-treated rabbits.

b. Skin test 1. The reference procedure was used. 2. I treated 6 rabbits for each sample, 4 samples per rabbit, 8 samples altogether: E, F, I, J, K, L, M, and N. 3. 0 also treated his 12 rabbits as in step 2. 4. The readings and recording of results were independently performed by I and 0 as in step 4 in the eye retest procedure.

c. The investigator in each of the 2 laboratories will henceforth be denoted by letters other than I; each indicative of whether the same one treated and read in each test.

0 was requested to write his comments on any differences in interpretation of procedure techniques he observed. The 2laboratories selected for retest were laboratories 27 and 12. Reference to Table 61indicates that laboratory 27 ranked 23rd of 24 laboratories on the eye test and 21st of the 22 laboratories on the skin test, while laboratory 12 ranked 3rd and 1st on the eye and skin tests, respectively. Thus, laboratory 27 tended to read results less severely and laboratory 12 more severely than the majority of the other laboratories in this collaborative study. The results will bediscussed separately for each of the eye and skin tests in each of the 2 laboratories and then the readings in both laboratories will be compared.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 345

1. Eye test-Laboratory 27.The medianscores arepresentedin Table 63for eachof the6materialsappliedand/or readby 0, theindependentobserver, 

### andby R,the same technician in laboratory 27who originally appliedthematerialsandreadthe resultsin
TABLE 63 SCORESAND COMPARISONSOF REFERENCEEYEPROCEDURE IN LABORATORY 27 WHERE Two TECHNICIANS APPLIED MATERIALS AND/OR READ RESULTS
Median score for material Applied Read __.- 

### Line by by F J K L M N
1 0” 

### 0 29 18 15.5 25.5 33.5 43 2 0 R” 38 28 2 40.5 22.5 34 3 R R 18 21.5 24 20 24.5 16.5 4 R 0 28.5 31.5 25 23.5 24.5 26 S’ R R 24 9.5 4 20 24 2

l-l 0 

### 0 2 4 3 2 1 1 2-1 0 R 1 2 4 1 4 2 3-l R R 4 3 2 4 2.5 4 4-l R 0 3 1 1 3 2.5 3 Rank for lines 1to 4

Rank for lines 1 to 5 Sum of ranksQ
13 14 19.5 13.5 Sum of rankse
l-2 0 

### 0 2 4 3 2 1 1 13 2-2 0 R 1 2 5 1 5 2 16 3-2 R R 5 3 2 4.5 2.5 4 21 4-2 R 0 3 1 1 3 2.5 3 13.5 5-2 R R 4 5 4 4.5 4 5 26.5 Signed rank test comparisons



### First > second First c second 

### (+I (-) Tie 

### 1vs.2 00 US.

OR 3 1 vs.3 00 vs. RR 4 1 vs.4 00 vs.RO 4 2 vs.3 OR us .RR 3 2 vs.4 

### ORvs.RO 3 3 vs.4 

### RR vs.RO 0 3 vs.5 RR vs.RR 4 Mean values compared where :

- 0 or R applied 4 0 or R read 5 3 0 2 0 2 0 3 0 3 0 5 1 1 1

2 0 14.5 6.5 2 1 0 17 4 2

Sum of signedS

T ranks - ranks cc0.s5limit for

smaller sum
10.5 10.5 17 4 12 9 12 9 12 9 0 159 13 2

’ 0 designates an independent observer, R an investigator from laboratory 27. bPrevious results from laboratory 27.

=ccg,05 = 8to 22. dRank of 1given to most severereading; therefore, smaller sum of ranks ismore severethan larger. ec(,-,.,,~ = 9 to 27. ’ Larger sum of signed ranks indicates more severe reading than smaller sum. BP cc0.05.

### 346 WEIL AND SCALA

TABLE 64

SCORES AND COMPARISONS OF REFERENCE SKIN PROCEDURE IN LABORATORY 27 WHERE Two TECHNICIANS APPLIED MATERIALS AND/OR READ RESULTS
Primary irritation score for material Applied Read Line -by 

### by E F I J K L M N

56

l-l 2-1 3-l 4-1

l-2 2-2 3-2 4-2 5-2 0” 0 R R R

0 0 R R

0 0 R R R 0 R” R 0 R

0 R R 0

0 R R 0 R 

### - 0.17 1.67 1.17 1.83 2.17 5.50 1.00 1.67 1.00 2.50 3.33 4.50 0.67 1.50 1.33 0.67 2.17 17.33 0.83 3.67 0.83 2.00 1.50 20.33 0.1 4.0 0.2 1.9 2.0 5.0

Rank for lines 1to 4

4 2.5 2 3 2.5 3 1 2.5 3 1 1 4 3 4 1 4 2.5 2 2 1 4 2 4 1

Rank for lines 1to 5

4 3.5 2 4 2.5 3 1 3.5 3 1 1 5 3 5 1 5 2.5 2 2 2 4 2 5 1 5 1 5 3 4 4 0.67 0.00 0.33 0.00 1.67 0.83 1.00 1.50 0.8 0.0 Sum of

ranksc’d

3 3.5 4 3.5 1 2 2 1 23.5

20.5 19.5 17.0 Sum of rankse

4 4 27.0 5 4 23.5 1 2 21.5 2 1 19.0 3 4 29.0

1 vs.2 00 vs.OR 1vs.3 00 us. RR 1 vs.4 00 vs. RO 2 vs.3 OR vs. RR 2 vs.4 OR vs. RO 3 vs.4 RR vs.RO 3 vs.5 RR vs. RR Mean values compared where : 8 13 2 8 20 4 8 28 6 15.5 20.5 6 12 24 6 10 26 6 23 13 6

0 or R applied 2 5 1 6.5 21.5 4 0 or R read 4 4 0 22.5 13.5 6 Signed rank test comparisons

Sum of signedf First > second First c second tc0.05limit for (+I C-1 Tie -t ranks - ranks smaller sum

-

’ 0 designates an independent observer, R an investigator from laboratory 27. bPrevious results from laboratory 27. cLQ.05= 12to 38. dRank of 1given to most severereading; therefore, smaller sum of ranks ismore severethan larger. ‘?c(o.tJ5 = 13to 35. f Larger sum of signed ranks indicates more severe reading than smaller sum.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 341

the first test in this laboratory. On line 5in this table are presented the previous readings by R. The median scores were much lower previously than in the retest, especially for samples J, K, and N. When lines 1to 5were ranked, the sum of ranks (line 5-2) for the previous readings were close to being significantly different from all of the others (ranks of 4 to 5 for each sample, with the current application and reading by R being a close second (line 3-2). Therefore, the tendency was, previously and in the retest, for Rto score less severely than others. When Rapplied, and 0 read (line 3), this tendency disappeared. Therefore, the difference appeared to be in the reading, not the application. The signed rank test was used to more powerfully delineate differences or similarities in the paired application and reading procedures. One statistically significant difference
was found, for RR (applied by Rand read by R) versus RO (applied by Rand read by 0). Here, for 5 of 6 materials, R scored the cornea1 injuries less severely than O-the previous overall tendency of this laboratory. The trend (this term, trend or tendency, will beused when the results were close to, but not, statistically significant) of lines 1versus 3 (00 versus RR) were also in this direction. Similarly 3 uersus 5, the current RR versus the previous RR, again indicated that the current results were read as more severe corneal injury than the previous. When the scores of the 0 applications were compared with those of the R applications, as well as when the 0 readings were compared with the R readings, the R
scores were less severe in each case; asstated before, this was the previous tendency of this laboratory. 0 did not observe any difference in technique or interpretation of the protocols of the reference procedure by R, with the possible exception that 0 noted
more iritis than did R. 2. Skirt test-Laboratory 27. The primary irritation scores are presented in Table 64 for each of the 8 materials applied and/or read by 0 and by R. As in the eye test, the previous readings (line 5) tended to be less severe than the current ones (line 3). In the signed rank comparisons, the tendency was for the current results to be more severe when R applied than when 0 applied. 0 observed asignificant departure from protocol in the technique of R. The Saran sleeve was left double, placed over the patches and taped tightly to the animal by wrapping masking tape completely around the rabbit. This would allow drastic exposure to test chemicals, much in excess of that intended in the protocol. This obviously occurred in sample L, where necrosis resulted from the R, but not from the 0, application. The rabbits treated by 0 were read, for material L, as reversible eschar (which 0 remarked would have to be judged later than 24 hr after treatment to determine the presence or absence of necrosis; all readings in the retest
were made only at 24 hr). On the line 1versus 4 comparison, 00 versus RO, the trend was, again, toward more severe readings when R applied. 3. Eye test-Laboratory 12. The scores and comparisons of the reference eye procedure in laboratory 12, when applications and readings were made by 0 or by N, are presented in Table 65. Note that technician N was not the same as the one who previously applied (Q) or read (D) the results in laboratory 12. As mentioned earlier, the previous readings of results in laboratory 12were more severe than in the majority of the other laboratories. In the retest (on lines l-l to 4-l), NN (N applied and N read) results were definitely (statistically significantly) the most severe, with NO (N applied, 0 read) results significantly the least severe; the 00 combination was similar to that for NO.

### 348 WEIL AND SCALA

TABLE 65 SCORES AND COMPARISONS OF REFERENCE EYE PROCEDURE IN LABORATORY 12

WHERE Two TECHNICIANS APPLIED AND/OR READ RESULTS

- Median score for material Applied Read Line by by F J K L M N
1 0” 0 i6 14.5 8 24.5 18 11 2 0 N” 34.5 34 12 24 32.5 24.5 3 N N 34 36 14.5 43 34.5 33 4 N 0 15.5 7 9 14 8 17 5b Q D” 43 41 34 47 46 39 Sum of Rank for lines 1 to 4 rankscJ
l-l 0 0 3 3 4 2 3 4 19 2-l 0 N 1 2 2 3 2 2 12 3-l N N 2 1 1 1 1 1 7” 4-l N 0 4 4 3 4 4 3 22’ Sum of Rank for lines 1 to 5 ranksf

-____ ..-.____ --- 1-2 0 0 4 4 5 3 4 5 25 2-2 0 N 2 3 3 4 3 3 18 3-2 N N 3 2 2 2 2 2 13’ 4-2 N 0 5 5 4 5 5 4 28’ 5-2 

### Q D 1 1 1 1 1 1 6”

Signed rank test comparisons

l-us. 2 00 vs.ON 1’~s. 3 00 vs. NN 1 vs.4 00 vs.NO 2 vs.3 ON vs.NN 2 vs.4 ON us. NO 3 vs.4 NN vs. NO 3 vs.5 NN vs.QD Mean values compared where : Sum of signedg

First > second First c second ~ o~~.~s limit for (+) t-1 Tie + ranks -ranks smaller sum

1 5 0 1” 20 2 0 6 0 0’ 21 2 4 2 0 16 5 2 1 5 0 1’ 20 2 6 0 0 21 0’ 2 6 0 0 21 0’ 2 0 6 0 0’ 21 2

0 or N applied 3 3 0 9 12 2 0 or N read 0 6 0 0’ 21 2

a0 designates an independent observer, N an investigator from laboratory 12, Q the previous investigator who applied materials, and D the previous reader from this laboratory. bPrevious results from laboratory 12. cao.05= 8 to 22. dRank of 1given to most severereading; therefore, smaller sum of ranks ismore severethan larger. ;P < 0.05. ccO.OS = 9to 27. g Larger sum of signed ranks indicates more severe reading than smaller sum.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 349

In the lines 1 to 5 comparisons (lines l-2 to 5-2), the same trends were present but here the previous results (QD) were the most severe, NN being significantly the next most severe, and NO significantly least severe, and similar to 00. In the signed rank comparisons, many statistically significant differences were seen.

00 vs. ON-N read more severely 00 vs. NN-NN results more severe than 00 ON vs. NN-N read more severely when he applied the materials than when 0

applied ON vs. NO-N read more severely when 0 applied than 0 read when N applied NN vs. NO-N applied, but N read more severely than 0 NN vs. QD-previous results more severe than retest
Overall, although N did not grade asseverely as QD had done previously, hedefinitely graded more severely than did 0, the independent observer. This grading was primarily the result of reading the results more severely than 0, not of differences in technique. 0 observed that N followed the protocol precisely. 4. Skin test-Laboratory 12. The primary irritation scores and their comparisons are presented in Table 66. Note here, as in the eye retest in laboratory 12, a different technician applied and read the skin test results in the retest than in the previous test in this laboratory. The only significant finding on comparison of sum of ranks was that the previous results, QQ, were different from all of the retest ones-for 7of the 8chemicals QQ obtained ranks of I-most severe. Note particularly PI scores of 18.5 vs. 4.0 for material F; 11.2US.

0.67 for material M ;2.0 vs. 0.0 for material I, and 3.2 vs. 0.0 for material N for previous results vs. current (retest) results, respectively. In the signed rank comparisons, the following were noted:

00 vs. OF-F tended to read more severely than 0 when 0 applied 00 vs. FF-FF results were more severe than 00 OF US.FF-F had more severe readings when heapplied than when 0 applied FF vs. FO-F read more severely than 0 on rabbits treated by F FF vs. QQ-previous laboratory 12test results were more severe than in retest

In the overall reading, F definitely read more severely than 0. 0 observed that F followed the protocol precisely. 5. Intercomparisons of retest and previous test scores. Table 67 presents the eye and skin test scores for the retest and previous test results in laboratories 27 and 12, aswell
asthe scores for 0 in both laboratories during these retests. On the eye test, 0 consistently read higher, more severely, in laboratory 27than hedid in laboratory 12(columns 1vs. 2). The same tendency was present, although here not statistically significant, for 0 for the skin test (7 US.8). Contrariwise, N in laboratory 12 had more severe readings than did R in laboratory 27for the eye(columns 3vs. 4) and skin (columns 7vs. 10) tests. Thus, 0 in laboratory 27 had higher scores than in laboratory 12,but R in laboratory 27 had lower scores than N in laboratory 12-both being retest results. In previous testing, laboratory 27 was consistently less severe than laboratory 12on both eye and skin tests (columns 5US.6 and 11vs. 12). Therefore, while the previous trend of less severe results

### 350 WEIL AND SCALA

TABLE 66 SCORESAND COMPARISONSOFREFERENCE SKINPROCEDUREIN LABORATORY 12

WHERE TWOTECHNICIANSAPPLIEDAND/ORREAD RESULTS

Applied Read Primary irritation score for material

Line by

1 2 3 4 9

1-l 2-1 3-l 4-l

l-2 2-2 3-2 4-2 5-2

--~ 

### 0”

0 F F Q

0 0 F F

0 0 F

G by E F I J K L M N

0 0.33 -1.17 0.50 1.50 1.33 5.50 1.17 0.17 F” 0.50 1.00 0.67 1.83 2.00 14.70 1.17 0.00 F 2.17 4.00 0.00 2.83 3.50 15.00 0.67 0.00 0 1.00 1.00 0.33 2.50 2.50 5.00 0.67 0.00 

### Q 1.1 18.5 2.0 4.2 5.2 22.6 11.2 3.2 Sum of Rank for lines 1 to 4 ranksEed

04 22 4 4 3 1.5 1 21.5 F 3 3.5 1 3 3 2 1.5 3 20.0 F 1 1 4 1 0 2 3.5 3 2 : 1 3.5 3 15.5 4 3.5 3 23.0 Sum of Rank for lines 1 to 5 rankse

-~~ 05 33 5 5 4 2.5 2 29.5 F 4 4.5 2 4 4 3 2.5 4 28.0 F 1 2 5 2 2 2 4.5 4 22.5 3 4.5 4 3 3 5 4.5 4 :21111 111 31.0 9.0s

Signed rank test comparisons

Sum of signedg First > second First c second c(0,05limit for (+I (-) Tie + ranks - ranks smaller sum

1 vs.2 00 vs.OF 1 vs.3 00 vs. FF 1vs.4 00 vs.FO 2 vs.3 OF vs. FF 2 vs.4 OF vs. FO 3 vs.4 FF vs. FO 3 vs.5 FF vs.QQ Mean values compared where: 1 5 23 0 6s 30 0 15 21 1 5 23 2 10 11 2 19.5 1.5f 0 1’ 35

0 or F applied 4 4 0 10 26 6 0 or F read 2 5 1 3f 25 4

’ 0 designates an independent observer, F an investigator from laboratory 12, Q the previous investigator from this laboratory. * Previous results from laboratory 12. Pc(,,.05 = 12 to 28. dRank of 1given to most severereading; therefore, smaller sum of ranks ismore severethan larger. eQ.05 = 13 to 35. f P < 0.05. gLarger sum of signed ranks indicates more severe reading than smaller sum.INTERCOMPARISONS OF RETEST AND TEST SCORES IN 

### Two LABORATORIES 

### Applied and read by” Applied and read by“ Applied and Applied and __- read by 0” R N R 

### Q>D read by 0” R F R 

### Q Eye test-24-hour median score Skin test-primary irritation score
- -- Retest First test Retest First test

Lab. Lab. Lab. Lab. Lab. Lab. Lab. Lab. Lab. Lab. Lab. Lab. 2 Material 21 12 27 12 27 12 Material 27 12 27 12 27 12 ;;1 F Column $ 1 2 3 4 5 6 7 8 9 10 11 12 %

.-~. 2; F 29 16 18 34 24 43 E 0.17 0.33 0.67 2.17 0.1 1.1 J 18 14.5 21.5 36 9.5 41 F 1.67 1.17 1.50 4.00 4.0 18.5 2
K 15.5 8 24 14.5 4 34 I 1.17 0.50 1.33 0.00 0.2 2.0 3 L 25.5 24.5 20 43 20 47 J 1.83 1.50 0.67 2.83 1.9 4.2 M 33.5 18 24.5 34.5 24 46 K 2.17 1.33 2.17 3.50 2.0 5.2 Fi N 43 11 16.5 33 2 39 L 5.50 5.50 17.33 15.00 5.0 22.6 M 0.67 1.17 1.67 0.67 0.8 11.2 w N 0.00 0.17 0.83 0.00 0.0 3.2 2

i Signed rank test comparisons i Sum of signed tj Columns First > second First x second 010,05 limit for 2 v1 No. (+I C-1 Tie + ranks - ranks smaller sum
1vs. 2 6 0 0 21 Ob 2 3vs. 4 1 5 0 ;: 20 2 5vs. 6 0 6 0 21 2 7 vs. 8 4 3 1 20.5 7.5 4 9 vs. 10 4 4 0 13.5 22.5 6 11vs. 12 0 8 0 Ob 36 6 E C-L dSeeTables63-66 for definitions of 0, R, N, Q, D, and F. bP < 0.05.

### 352 WEIL AND SCALA



### in laboratory 27 than in laboratory 12was duplicated in the retest results with the previous and current technicians in these laboratories (different ones for laboratory 12for the rerun than for the previous test), the independent observer, 0, had the opposite trend. It is therefore concluded that the major differences between these two laboratories-which scored at the opposite extremes in the previous tests-could not have been primarily produced by differences in the stocks of rabbits used, but was largely the result of different grading by the technicians. It is noteworthy that the trained observer, 0, obtained different readings in different laboratories with these tests. Furthermore, the tendency in each laboratory in the retest to read more like the average laboratory and less extremely than in the first runs, might have been the result of more careful interpretation of the protocol and definitions involved when the technicians knew they were to be observed by an independent technician.

DISCUSSION AND CONCLUSIONS
The tests currently used by most laboratories for rating materials for the degree of eye or skin irritation are the same as or minor modifications of the Draize, or FHSA, procedure. The reference procedures, used by 24 laboratories for the eye and by 22 for the skin tests, were also quite similar to the above. It was clearly demonstrated that several laboratories were outliers. They consistently read either more severely or less severely than most other laboratories. Thus, the tests which have been used for over 20 years to decide the degree of eye or skin irritation produce quite variable results among the various laboratories as well as within certain laboratories. To use these tests, or minor variations of them, to obtain consistency in classifying amaterial as an eye or skin irritant or nonirritant, therefore, is not deemed practical. All the collaborative tests were performed with aliquots of reference samples. Considerably more variation would be expected if independently produced samples had been used. The extreme variation between laboratories cannot be entirely explained by any one of the many factors involved. In most cases, judged by the retest performed in 2 of the laboratories, the primary reason for differences was in the reading of reactions, as opposed to variation in interpretation of and performance of the procedures. The latter, however, was also a component of the interlaboratory variability. The variability in total eye injury scores or in average primary skin irritation scores was also present, as might have been expected, in the reading of the components of these
scores. Thus, the words used to describe injury of the conjunctiva, the iris, or the lid of the eye or to describe erythema, edema, or necrosis of the skin are interpreted differently by many different laboratories. A change in the “standard” procedures currently used,
or in the descriptions or definitions of the degrees of injury, would probably not suffice. The most efficient way to have less variability between laboratories, i.e., between individual technicians, would probably be to conduct courses or clinics in methodology. These would have to be repeated at frequent intervals to accommodate new technicians
or new toxicologists. In the meantime, it is suggested that the rabbit eye and skin procedures currently recommended by the Federal agencies for use in delineation of irritancy of materials should not be recommended as standard procedures in any new regulations. Without careful reeducation these tests result in unreliable results.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 353

The outlying laboratories, those which read consistently high or low, were distributed practically equally between the consultant, the toilet goods or cosmetic, the food
or industrial chemical, and the governmental laboratories that took part in this collaborative test. Therefore, the suggestion that any one type of laboratory do all of the irritation testing is as impractical as the suggestion that any one type of laboratory do any of the toxicity tests, e.g., for chronic injury, for carcinogenicity, for teratology, for mutagenicity, etc. Unconscious bias or definite tendencies to over- or underread reactions or misinterpret the meaning of descriptive terms can be counteracted only by having several or many laboratories perform similar tests. It is obvious that this is not the time to recommend any standard or reference procedure in this or in most of the other phases of degree of hazard testing. The more varied the approach to this, the
sooner better techniques can be developed which might lead to more uniform results.

SUMMARY


### 1. In testingreferencesamples bythereferenceeyeorskinirritation procedures,most laboratories rated relatively nonirritating materials similarly. These materials were eliminatedfrom mostoftheinter- andintralaboratory comparisonsto preventfictitious correlations. 2. Therangein eyeor skinirritation scores betweenindividual rabbits wasrelatively large in somelaboratories and smallin others. 3. Eye healingwith mostmaterialswasnoted in mostlaboratories during the 7-day observation period; in others the injuries progressed. 4. The scores

for thecomponentsof thetotal scorefor the eyetest(for theinjury to the cornea, iris, and conjunctivae) also varied considerably among the individual rabbits treated andamongthe 24laboratories that usedthe referenceprocedure. Similarly, thedegree

of erythema,edema,andnecrosis reported ontheskintestby22laboratoriesfor the 10materialstestedin the referenceprocedure varied from no reaction to
severeirritation andtissuedamage. 5. Certain laboratories consistently recorded unusually severescores(indicated by
sumof ranks)for thematerialstestedinthereferenceeyeand/or skinprocedures;other laboratories reported consistently nonirritating scores(interlaboratory comparison). 6. Certain materialswere rated asthe most irritating testedby somelaboratories and, contrariwise, asthe leastirritating by others. 7. The variability (indicated by semi-interquartile range)amongtheinterlaboratory ranking wassmallfor someandlargefor other laboratories. Thus, somelaboratories varied considerably in relative rating of materials,othersgenerallytendedto ratemost materials more severelythan other laboratories, and still others consistently rated materialsnonirritating. 8. Generally, the reading of relatively severeeye or skin reactions in particular laboratories wascorrelated with low variability onreadingsamongindividual rabbits. 9. The relative interlaboratory position for severity of orvariability amongreactions recordedwasunrelated to thetype of laboratory. Someoutlierswereconsultant, some toilet goodsor cosmetic,somefood or industrial chemical,andsomeweregovernment laboratories.

### 354 WEIL AND SCALA



### 10. More agreement on the relative ranking of the irritation potential of the samples
was found among the laboratories (intralaboratory comparison) than on the relative ranking of the laboratories by their readings of the irritancy of the samples (interlaboratory comparison). Nevertheless, many laboratories lacked significant correlation in intralaboratory sample ranking compared with the overall laboratory sample ranks. 11. More laboratories (10 of 16) lacked significant correlation between reference and nonreference procedures on the eye than on the skin tests (3 of 19 laboratories). This
was true for the eye test in many cases when the reference and non-reference procedures
were almost, or completely, identical. 12. The all-or-none, irritant or nonirritant, eye or skin rating of the reference samples

was determined quite differently in different laboratories. 13. There was atendency for asignificant correlation between the severity of scoring eye and of skin reactions in most of the laboratories. However, some laboratories differed considerably in this. 14. In aretest of two outlying laboratories, the technicians tended to read in the same direction as before, but less extremely, while an independent observer who applied and read materials in both laboratories had the opposite tendency, i.e., he read less severely in the laboratory which, generally, read more severe reactions than most others, and vice versa. ACKNOWLEDGMENTS The authors wish to thank the Collaborative Study Steering Committee for their assistance inthe design of the procedures. We arealso deeplyappreciative of the time and effort expended by the personnel in each of the laboratories that participated and of the publication support supplied by Esso Research and Engineering Company, Linden, New Jersey.

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### 15,209-230. HAZLETON,

L. W. (1952).Relationof surface activeproperties

to irritation oftherabbit eye. Proc. Sci. Sect. Toilet Goods Ass. 

### (17),5-9. KAY, J.H., andCALANDRA, J.C. (1962).Interpretation ofeyeirritation tests. J. Sot. Cosmet. Chem. 13, 

### 281-289. RUSSELL, K. L., andHOCH,

S.G. (1962).Productdevelopment andrabbiteyeirritation. Proc. Sci. Sect. Toilet Goods Ass. (37), 27-32. 

### WELTMAN,

A. S.,SPARBER,

S.B., andJURTSHUK,

T. (1965).Comparativeevaluationandthe influence ofvariousfactorsoneye-irritationscores. Toxicol. Appl. Pharmacol. 7,308-319.INTERLABORATORY EYE AND SKIN COMPARISONS 

### 351



## APPENDIX

Scale for Scoring Ocular Lesions* 

### (1) Cornea (A) Opacity-degree

of density(areamostdense takenfor reading) No opacity

. . . . . . . Scatteredor diffusearea,details bf irisclearlyvisible

. . . . Easilydiscernible

translucent

areas, details of irisslightlyobscured

. . Opalescent

areas, nodetailsofirisvisible,size of pupilbarelydiscernible

. Opaque,irisinvisible . 0

. 1

. 2

. 3 (B) Area of corneainvolved ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ 4

Onequarter(orless)

butnotzero

. 1 Greaterthanonequarter,but less thanhalf : : : : : : : 2 Greaterthan half, but less than threequarters

. . . . . . 3 Greaterthanthreequarters, uptowholearea

. . . . . . . 4 Score equals A x B x 5 

### Total maximum= 80 (2) Iris (A) Values Normal

. . . . . Foldsabovenormal,congestion, swelling . . circumcorneal

injection(anyor all of 0

theseor combinationof anythereof) i;is stillreactingto light (sluggishreaction ispositive)

. . . . No reactionto light,hemorrhage,‘gross destruction(anyorall’of these) : . 1

. 2 Score equals A x 5 

### Total maximum= 10 (3) Conjunctivae (A) Redness

(refersto palpebral

andbulbarconjunctivaeexcludingcorneaandiris)

. 0 Vessels normal

. . . . . . . . . . 0 Vessels definitely injectedabovenormal

. . . . . . 1 More diffuse,

deeper crimsonred,individualvessels noteasily discernible

. . 2 Diffusebeefyred

. . . . . . . . . . . 3 (B) Chemosis No swelling

. . . . . . . . . . . . 0 Any swelling

abovenormal(includes

nictitatingmembrane)

. . . . 1 Obviousswelling

withpartialeversion

oflids

. . . . . . . 2 Swellingwith lidsabouthalf closed

. . . Swelling withlidsabouthalfclosed tocompletely

closed : . . . . 3

. . . . 4 (C) Discharge No discharge

. . . . . . . . . . . 0 Any amountdifferentfrom normal(does not includesmallamounts observed in innercanthusof normalanimals)

. . . . . . . , 1 Discharge

withmoistening

ofthelidsandhairs

justadjacent

tolids

. . . 2 Discharge

with moistening

of thelidsandhairs,andconsiderable areaaround theeye Score equals (A 

### + B 

### i C’)i 2 ’ ’ ’ ’ ’ ’ ‘Total’maximum12:
Themaximum

total score

isthesumofallscores

obtainedforthecornea,iris,andconjunc

### tivae. Total maximumscore possible = 110. * Draizeetal.(1944).A.?. DATA SHEET Rabbit E),e Irritatiorl Scores Refretlce Procedure

Sample:

1 Hour 24 Hours Laboratory:
Date of Application:

71 Hours I Davs

I. Cornea

B. Area involved

B. Chemosis

Applied by : Graded by:

Round Robin Program for Eye and Skin IrritantsINTERLABORATORY EYE AND SKIN COMPARISONS 

### 359

B. 1. Scoring and Evaluation-Reference Skin Test The parameters of (1) Erythema, (2) Edema, and (3) Necrosis will be evaluated for each chemical on all animals using the following scoring system: (1) Erythema No erythema 0 Very slight erythema (barely perceptible) 1 Well-defined erythema 2 Moderate to severe erythema 3 Severe erythema (beet redness) 4

Total possible erythema score per animal for combined 24- and 72-hour reading 8 (2) Edema No edema 0 Very slight edema (barely perceptible) 1 Slight edema (edges of area well defined by definite raising) 2 Moderate edema (raising approx. 1mm) 3 Severe edema (raising more than 1mm and extending beyond area of exposure 4

- Total possible edema score per animal for both 24- and 72-hour reading 8 (3) Necrosis* No necrosis 0 Slight necrosis (less than a of exposed area) 5 Moderate necrosis (+ to 3 of exposed area) 10 Severe necrosis (more than 3 of exposed area) 15

Total possible score for both 24- and 72-hour reading 30
* Necrosis for the purpose of this scoring systemis defined as a chemical denaturation of tissue sufficiently severeto result in fibrotic replacement (scar tissue). Superficial eschar which heals without
scar is not classified asnecrosis.B.2. DATA SHEET Rabbit Primary S’kin Irritation Scores--Reference Method

Sample: Laboratory:

_ Date of Application:

Total score I Primary Irritation Score

Sum of total scores/ 16 = primary irritation score

Applied by: Graded by:

Round Robin Program for Eye and Skin Irritants