This document is a draft for review purposes only and does not constitute Agency policy.

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### A.1. SUBCHRONIC ANIMAL TOXICOLOGY STUDIES FOR 1,2,3

- TMB

Table A

- 1

. Characteristics and quantitative results for Korsak and Rydzyński ( 1996 )

Study Design
Species Sex N Exposure

route Concent ration range Exposure duration

IMP:

Wistar M 10/dose Inhalation 25

- 250 ppm (123

- 1230 mg/m 3 ) 3 months (6h/day, 5 days/week) Additional Study details Animals were exposed to either 1,2,3

- , 1,2,4

- , or 1,3,5

- TMB in a dynamic inhalation chamber (1.3 m 3 volume) with 16 air changes/hour

. Mean initial body weights were 250

- 300 grams; rats were housed in wire mesh stainless steel cages, with food and water provided ad libitum

. Animals were randomized and assigned to the experimental groups.

Rotarod and hot plate tests were conducted to measure effects on neuromuscular activity and pain sensitivity respectively. Rotarod performance was tested immediately after termination of exposure.

N ormal neuromuscular function was indicated by the rats' ability to remain on a rod rotating at 12 rpm for 2 minutes

. Hot

- plate behavior was tested immediately after termination of exposure. Latency of 60 sec onds was considered as 100% inhibition of pain sensitivity.

A uthors also investigated the effects of exposure to 1,2,3

- , 1,2,4

- and 1, 3,5

- TMB on rotarod test performance and pain

- sensing response two weeks after the termination of exposure.

Observation Latency of the Paw

- Lick Response, sec

1,2,4

- TMB 1,2, 3

- TMB

Control 15.4±5.8 9.7±2.1 25 ppm (123 mg/m 3 ) 18.2±5.7 11.8±3.8*
100 ppm (492 mg/m 3 ) 27.6±3.2** 16.3±6.3 *** 250 ppm (1230 mg/m 3 ) 30.1±7.9** 17.3±3.4** 250 ppm (1230 mg/m 3 ) two weeks after termination of exposure 17.3±3.9 11.0±2.4

Health Effect at LOAEL NOAEL LOAEL

Decreased pain sensitiv i ty Control for 1,2,3

- TMB 25 ppm for 1,2,4

- TMB 25 ppm for 1,2,3

- TMB 100 ppm for 1,2,4

- TMB

Comments: Although rotarod data are useful in providing a qualitative description of neuromuscular impairment following 1,2,4

- TMB or 1,2,3

- TMB exposure, in comparison to

effects on pain sensitivity, the data are not considered as robust regarding suitability for derivation of reference values. Namely, data are presented as dichotomized values instead of a continuous measurement of latency.

*, ** statistically significant from co ntrols at p ≤ 0.05 and p≤0.01, respectively *** Level of significance not reported in Table 1 from Korsak and Rydzyński ( 1996 ) , however the results of an ad

-This document is a draft for review purposes only and does not constitute Agency policy.

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- test (performed by EPA) indicated significance at p < 0.01

1

Table A

- 2 . Characteristics and quantitative results for Korsak et al. ( 2000b ) 2

Study Design
Species Sex N Exposure ro ute Concentration

range Exposure

duration

IMP:

Wistar M &

F 10/dose, 20 in 1230mg/m 3

group Inhalation 0, 123, 492, 1230 mg/m 3 90 days

(6h/day, 5 d/ week) Additional Study details Animals were exposed to 1,2,3

- TMB in a dynamic inhalation chamber (1.3 m 3 volume) with 16 air changes/hour

. Mean initial body weights were 290±25 g for males and 215±13 g for females; rats were housed in polypropylene cages with wire

- mesh covers (5 animals/cage), with food and water provided ad libitum

. Animals were randomized and assigned to the experimental groups

. Hematological parameters were evaluated prior to exposure and 1 week prior to termination of exposure , and for the 1230 mg/m 3 exposure group, also evaluated two weeks after termination of exposure ; blood clinical ch emistry parameters were evaluated 18 hours after termination of exposure (animals were deprived of food for 24 hours) Necropsy was performed on all animals. Pulmonary effects were graded using an arbitrary scale: 0 = normal status, 1 = minimal, 2 = mild, 3 = moderate, 4 = marked

Observation Exposure Concentration (mg/m 3 )

0 123 492 1230

Body and Organ weights (mean ± SD)

Males Terminal Body weight (g) 390±35 408±50 404±33 413±46 Absolute organ weight (g)
Lungs 1.90±0.22 1.86±0.26 1.99±0.37 1.88±0.34

Liver 8.28±0.97 8.83± 1.40 9.05±0.99 9.54± 1.50 Spleen 0.71±0.06 0.12±0.10 0.82±0.11 0.79±0.20 Kidney 2.34±0.27 2.29±0.23 2.48±0.25 2.50±0.25

Adrenals 0.059±0.012 0.061 ±0.016 0.061 ± 0.013 0.061 ±0.012

Testes 3.78±0.44 3.69±0.24 3.71 ±0.36 3.91 ±0.12

Heart 1.04±0.13 0.98 ±0.11 1.08±0.13 1.15 ±0.19 Relative organ weight (g)
Lungs 0.510±0.071 0.479±0.026 0.504±0.082 0.468 ± 0.073

Liver 2.208 ±0.163 2.271 ±0.129 2.287±0.115 2.414 ±0.214 * Spleen 0.190±0.019 0.187 ± 0.015 0.207 ±0.021 0.203 ± 0.058 Kidney 0.623 ±0.049 0.594 ± 0.029 0.629 ± 0.033 0.637 ±0.060This document is a draft for review purposes only and does not constitute Agency policy.
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— DO NOT CITE OR QUOTE Adrenals 0.016 ±0.003 0.016±0.003 0.015 ±0.003 0.016 ± 0.003

Testes 1.014±0.087 0.961 ±0.091 0.941 ±0.063 1.002±0.106

Heart 0.277 ±0.027 0.252±0.018 0.274±0.032 0.284±0.026

Females Terminal Body weight (g) 268±18 262±21 263±14 259±23 Absolute organ weight (g)
Lungs 1.62±0.15 1.55±0.33 1.47 ±0.18 1.51±0.16

Liver 6.05±0.42 5.85±0.47 5.94±0.51 6.05±0.44 Spleen 0.63±0.05 0.61±0.10 0.57±0.05 * 0.56±0.06 * Kidney 1.58±0.16 1.53±0.12 1.54±0.10 1.62±0.16

Adrenals 0.080±0.014 0.082±0.010 0.083 ±0.011 0.075 ± 0.015

Ovaries 0.12±0.03 0.12±0.03 0.13±0.02 0.14±0.04

Heart 0.74±0.05 0.71±0.50 0.75±0.06 0.73±0.08 Relative organ weight (g)
Lungs 0.651 ±0.053 0.637 ±0.122 0.604 ± 0.049 0.639±0.076

Liver 2.434 ±0.143 2.400 ± 0.088 2.448±0.190 2.555 ± 0.214 Spleen 0.257 ± 0.027 0.249 ± 0.032 0.234±0. 0 19 0.237±0.022 Kidney 0.639±0.076 0.628 ± 0.024 0.638 ±0.032 0.686 ± 0.058

Adrenals 0.032 ± 0.005 0.034 ± 0.004 0.034±0.005 0.032±0.008

Ovaries 0.051±0.014 0.050±0.014 0.056 ±0.006 0.060±0.018

Heart 0.298±0.016 0.291 ± 0.012 0.309 ± 0.024 0.307 ± 0.026

Observation Exposure Concentration (mg/m 3 )

0 123 492 1230 1230 a Trend

test b
Hematological parameters (mean ± SD)
Hematocrit (%) Males 46.4± 1.6 45.8±2.6 45.7±1.3 45.5±2.1 43.5±26 0.1615 Hematocrit (%) Females 42.7±2.2 45.0±2.4 41.8 ± 1.6 41.5±24 41.7±20 0.0198 Hemoglobin (g/dL) Males 16.4± 1.0 17.6± 1.6 17.6±0.8 15.0± 1.2 ND 0.0688 Hemoglobin (g/dL)

Females 13.9±0.7 15.1 ± 1.0* 14.6±0.6 14.7±0.9 ND 0.0748

RBCs (× 10 3 /mm 3 ) c Males 9.49±2.03 10.25±1.29 10.11 ±1.27 8.05 ± 1.38* 8.6±1.5 0.0011 RBCs (× 10 3 /mm 3 ) c
Females 8.03±

1.11 8.73± 1.24 7.79±1.57 7.27 ± 1.32 6.6± 1.8 0.0185

WBCs (× 10 3 /mm 3 ) d

Males 10.09±2.2

3 9.38±3.29 7.71±3.45 9.03±275 6.3±4.6 0.1661

WBCs (× 10 3 /mm 3 ) d

Females 10.71

±4.28 9.54±2.37 13.02±3.07 13.01 ±4.53 62±2.5 0.0189

Rod neutrophil (%) Males 0.8± 1.0 1.0± 1.1 0.4±0.5 0.5±0.6 5.2±3.0 0.1878 Rod neutrophil (%)

Females 0.4±0.8 0.6±0.6 1.1 ± 1.4 0.4±0.8 1.8±22 0.4711

Segmented neutrophil (%)

Males 24.8±4.5 25.4±5.8 20.7±5.8 17.7±8.3* 27.5±9.2 0.0032

Segmented neutrophil 23.1 ±6.1 19.7±3.4 16.4±4.2* 11.9± 7.1 ** 19.6±8.3 0.0000This document is a draft for review purposes only and does not constitute Agency policy.

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— DO NOT CITE OR QUOTE (%)Females Eosinophil (%) Males 1.3± 1.4 0.8±1.0 0.8±1.1 0.6±0.8 0.6±0.6 0.1439 Eosinophil (%) Females 1.4± 1.0 0.6±0.6 0.7±0.8 0.8±0.9 0.7±0.8 0.2778

Lymphocyte (%) Males 71.2±5.0 71.6±6.8 75.4±4.7 79.3±78.0

** 63.7 ±

11.3 0.0015

Lymphocyte (%) Females 73.2±7.9 77.5±4.9 80.4±5.1 84.0±78.0

** 75.7±9.9 0.0003

Monocyte (%) Males 1.9± 1.6 1.3 ± 1.4 2.3±20 1.6±22 3.1 ±3.7 0.3014 Monocyte (%) Females 2.0±2.0 1.6± 1.6 1.1±1.3 2.1 ± 1.7 1.3± 1.8 0.2426 Lymphoblast (%) Males 0.0±0.0 0.0±0.0 0.2±0.6 0.2±0.6 0.0±0.0 0.2911 Lymphoblast (%) Females 0.0±0.0 0.0±0.0 0.1±0.3 0.3±0.7 0.0±0.0 0.1403 Myelocyte (%) Males 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.5000 Myelocyte (%) Females 0.0±0.0 0.0±0.0 0.0±0.0 0.5 ±0.2 0.0±0.0 0.3963 Erythroblast (%) Males 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.5000 Erythroblast (%) Females 0.0±0.0 0.0±0.0 0.0±0.0 0.1 ±0.3 0.0±0.0 0.2995 Reticulocyte (%) Males 2.8±1.3 2.1 ± 1.7 3.8±2.1 4.5 ± 1.8* 6.9±3.1** 0.0017 Reticulocyte (%) Females 2.6±0.9 4.6±2.5* 5.2± 0 .50 4.4±3.0 6.8±3.5 0.0459 Platelet (× 10 3 /mm 3 )

Males 262±51 266±70 257 ±81 242±76 277±80 0.1708

Platelet (× 10 3 /mm 3 )

Females 224±68 290±70 249±53 204±44 258±45 0.0329

Clotting time (sec) Males 29.7±8.

6 23.0±10.0 37.9±9.9 29.2±15.6 21.7±5.4 0.4650

Clotting time (sec)

Females 27.2±2.

8 25.0±9.4 23.8±9.5 25.1 ±

12.1 25.9±8.0 0.3479

Observation Exposure Concentration (mg/m 3 )

0 123 492 1230 Trend

test b

Clinical Chemistry Parameters (mean ± SD)

AST (U/dL) e Males 107.8±14.2 102.9±15.1 103.6±14.5 119.6±27.3 0.2223 AST (U/dL) e Females 96.1 ±9.4 96.9±9.9 117.1±23.9 104.6± 15.7 0.2118 ALT (U/dL) f Males 41.3±2.0 40.7±3.1 41.5±5.5 45.5±5.6 0.0637 ALT (U/dL) f Females 39.7±3.5 39.5±6.4 36.2±3.3 30.5±9.9 ** 0.1844 ALP (U/dL) g Males 70.5±15.2 70.6±11.7 66.5± 10.8 63.7±15.7 0.1518 ALP (U/dL) g Females 21.5±2.7 25.8±8.4 31.1±8.6* 30.5±9.9* 0.1740 SDH (U/dL) h Males 1.6±0.7 2.3± 1.3 2.5±0.9 2.7±0.7* 0.0083 SDH (U/dL) h Females 1.7±0.7 1.9±0.9 1.5±0.7 1.8± 1.0 0.0637 GGT (μU/ml) I Males 0.77±0.66 0.77±0.97 0.40±0.51 0.50±0.75 0.4700 GGT (μU/ml) I Females 0.55±0.72 0.44± 1.01 0.66± 1.11 0.30±0.48 0.2821

Bilirubin (mg/dL) Males 0.600±0.51

6 0.600±0.516 0.800±0.422 0.625±0.518 0.2594

Bilirubin (mg/dL)

Females 0.911

±0.348 1.161 ±0.469 0.930±0.463 0.976±0.421 0.3092This document is a draft for review purposes only and does not constitute Agency policy.
5 DRAFT

— DO NOT CITE OR QUOTE Total cholesterol (mg/dL)

Males 63.1 ± 10.1 62.2±11.6 64.5±16.2 65.0±9.1 0.0920

Total cholesterol (mg/dL)

Females 60.1 ±12.2 62.4±15.3 62.3±7.7 64.4±14.1 0.4775

Glucose (mg/dL) Males 95.5±13.1 110.8±14.7 100.2±15.2 114.5±20.6 0.0876 Glucose (mg/dL) Females 115.9±8.5 121.0±17.5 109.2±5.8 109.8±10.8 0.4838

Total protein (g) Males 7.84±0.13 8.02±0.50 7.76±0.27 8.04±0.59 0.3242 Total protein (g) Females 8.24±1.24 8.36±1.14 8.65±0.84 8.62±0.96 0.4036 Albumin (g) Males 3.15±0.73 3.15 ±1.33 3.08±1.30 2.95±1.12 0.2279 Albumin (g) Females 3.22±1.28 3.17 ±1.03 2.58±1.28 3.60±1.17 0.2408 Creatinine (mg/dL) Males 41.24±8.94 41.35 ± 11.28 40.79 ± 9.30 43.61± 13.10 0.3982 Creatinine (mg/dL)

Females 62.54±10.6

6 61.60±7.07 67.11 ±

10.86 59.71 ± 7.51 0.1641

Urea (mg/dL) Males 38.7±4.5 38.1±9.1 36.9±4.1 41.7 ± 7.5 0.1145 Urea (mg/dL) Females 42.0±5.5 43.5±4.4 40.0±4.3 39.0±29 0.4718 Calcium (mg/dL) Males 10.6±0.6 10.7 ±0.8 10.8±0.7 10.9±0.5 0.2449 Calcium (mg/dL) Females 11.1 ±0.8 11.7 ±0.3 11.8 ±0.2 11.8±0.7 0.3011 Phosphorus (mg/dL)

Males 8.60±0.95 8.26±0.60 9.19±0.88 9.41±0.55 0.1580

Phosphorus (mg/dL)

Females 6.56±0.70 6.25±1.17 6.41± 1.02 7.18± 1.09 0.4050

Sodium (mmol/L) Males 143.9±2.1 144.1 ± 1.5 143.9±25 144.8±24 0.4950 Sodium (mmol/L)

Females 144.0±1.5 143.8±1.3 142.7± 1.3 143.8± 1.4 0.3628

Potassium (mmol/L)

Males 4.70±0.35 4.45±0.28 4.75±0.37 4.97±0.56 0.2907

Potassium (mmol/L)

Females 4.52±0.41 4.51 ±0.43 4.28±0.41 4.37±0.34 0.4108

Chloride (mmol/L) Males 107.3±2.3 107.7 ±4.3 106.8± 1.8 106.5 ± 1.9 0.4353 Chloride (mmol/L)

Females 108.1 ±3.2 108.1±1.5 107.1± 1.3 107.2±23 0.0601

Observation Exposure Concentration (mg/m 3 ) [Dose group ID]

0 [1] 123

[2] 492

[3] 1230

[4] Comparison

to Controls c Trend

test b

Proliferation of peribronchial lymphatic tissue (0

- 3) j Males 2. 0 d (23.4) e 1.2

(11.5) 1.8

(22.0) 2.0

(23.5) 1

- 2* 0.2

Proliferation of peribronchial lymphatic tissue (0

- 3) j Females 24(22. 8) 1.3 (12.1) 1.5

(16.4) L3

(22.3) 1

- 2**; 1

- 3 0.2

Formation of lymphoepithelium in bronchii (0

- 3) Males 1.5 (23.9) 0.9

(14.9) 1.0

(16.0) 1.5

(25.7) 1

- 3*; 1

- 4** 0.3This document is a draft for review purposes only and does not constitute Agency policy.
6 DRAFT

— DO NOT CITE OR QUOTE Formation of lymphoepithelium in bronchii (0

- 3) Females 1.8 (27.9) 0.7

(11.1) 1.1

(16.9) 1.5

(23.8) 0.3

Goblet Cells (0

- 3) Males 1.8 (18.6) 1.5

(14.5) 2.5

(28.5) 1.8

(18.2) 0.18

Goblet Cells (0

- 3) Females 1.3 (11.9) 1.6

(16.9) 2.0

(23.1) 2.4

(28.4) 1

- 3*; 1

- 4** 0.001

Interstitial lymphocytic infiltration (0

- 3) Males 0.4 (18.0) 0.1

(14.1) 0.4

(18.0) 1.5

(31.0) 1

- 4* 0.006

Interstitial lymphocytic infiltration (0

- 3) Females 1.2 (23.7) 0.6

(15.3) 0.8

(17.9) 1.1

(22.9) 0.4

Alveolar macrophages (0

- 3) Males 0.9 (17.9) 0.9

(17.9) 1.2

(22.6) 1.2

(21.7) 0.15

Alveolar macrophages (0

- 3) Females 1.5 (26.1) 1.1

(21.1) 0.5

(17.8) 0.7

(14.8) 0.01

Bronchitis and broncho

pneumonia (0

- 4) Males 0.5 (20.1) 0.2

(16.6) 0.8

(23.8) 0.7

(19.5) 0.3

Bronchitis and broncho

pneumonia (0

- 4) Females 0.2 (17.6) 0.4

(22.5) 0.2

(17.5) 0.6

(21.8) 0.3

Cumulative score of all

individual Males 7.1 (19.8) 4.8

(11.2) 7.7

(24.2) 8.7

(25.8) 0.01

Cumulative score of all

individual Females 8.4 (24.9) 5.7

(13.5) 6.5

(16.8) 8.2

(24.6) 1

- 2* 0.4

Health Effect at LOAEL NOAEL LOAEL

Pulmonary lesions 492 mg/m 3 1230 mg/m 3

Comments : The observed inflammatory lesions are coherent with observations of increased inflammatory cell populations in bronchoalveolar lavage fluid due to 1,2,4

- TMB exposure in

Korsak et al. ( 1997 )

. The authors did not report the i ncidences of pulmonary lesions, but

rather the results of the Kruskall

- Wallis test. This makes it difficult to interpret the dose

response relationship and limits analysis of these endpoints to the NOAEL/LOAEL method rather than a BMD modeling method.

a Responses measured 14 days after termination of exposure

b p

- value reported from Jonckheere’s trend test

c Reports the results of pair

- wise statistical significance of exposure groups compared to controls (i.e., 1

- 3 would
indicate that the 492 mg/m 3 was statistically significantly different from controls)

d Mean

e Results presented as ranges of the Kruskal

- Willis test
*, ** statistically significant from controls at p ≤ 0.05 and p≤0.01, respectively 1This document is a draft for review purposes only and does not constitute Agency policy.

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— DO NOT CITE OR QUOTE 

# APPENDIX B. DOSE

- RESPONSE MODELING FOR

THE DERIVATION OF REFERENCE VALUES FOR

EFFECTS OTHER THAN CANCER

B.1. BENCHMARK DOSE MODELING SUMMARY

Table B

- 1

. Model predictions (constant variance) for increased latency to pawlick in male Wistar rats, 1,2,3

- TMB. ( Korsak and Rydzyński,

1996 )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 0.005704 262.2082 700.938 566.333

No model selected

as Test 2 p

- value

was < 0.1. Exponential 4 0.5461 254.2393 192.288 107.132

Exponential 5 b N/A 255.8749 201.187 111.315

Hill b N / A 255.874906 185.863 110.398

Linear Polynomial 2° Polynomial 3°

Power 0.01728 259.991214 577.555 442.59

a Constant variance case presented (Test 2 p

- value = 0.0.0001146). T his p

- value indicates that a constant variance model does not adequately describe the observed variances. BMDS recommends using a non

homogenous variance model.

b p

- value not reported due to estimated model parameters = dose groups
1

Table B

- 2

. Model predictions ( modeled variance) for increased latency

to pawlick in male Wistar rats, 1,2,3

- TMB. ( Korsak and Rydzyński,

1996 )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 <0.0001 259.5324 496.844 329.318

No model selected

as Test 3 p

- value

was < 0.1

. Exponential 4 0.301 241.4193 86.2091 46.7265

Exponential 5 b N/A 242.5858 113.028 51.9836

Hill b N/A 265.438765 334.7333 Not calculatedThis document is a draft for review purposes only and does not constitute Agency policy.
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— DO NOT CITE OR QUOTE Linear Polynomial 2°

Polynomial 3° c

Power 0.0003247 254.414778 319.651 195.989

a Modeled variance case presented (Test 3 p

- value = 0.07076). This p

- value indicates that a modeled

variance model does not adequately describe the observed variances.

b p

- value not reported due to estimated model parameters = dose groups

c The 3 rd degree polynomial model failed to converge.

1This document is a draft for review purposes only and does not constitute Agency policy.
9 DRAFT

— DO NOT CITE OR QUOTE Table B

- 3

. Model predictions ( modeled variance , high dose dropped )

for increased latency to pawlick in male Wistar rats, 1,2,3

- TMB. ( Korsak and Rydzyński, 1996 )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 0.07449 203.2651 192.144 131.627 Of the models that provided an adequate fit and

valid BMDL
estimate, the linear

model was selected

based on the lowest AIC (BMDLs differed by less

than 3

- fold). Exponential 4 b N/A 202.0839 104.546 52.5736

Linear Polynomial 2° Polynomial 3°

Power 0.2016 201.714812 152.065 97.1911

a Modeled variance case presented (Test 3 p

- value = 0.5008)

. Selected model in bold; scaled residuals for
selected model for concentrations 0, 123

, and 492 mg/m 3 were

- 0.102, 0.319, and

- 0.354, respectively

. b A goodness

- of

- fit p

- value was not calculated for the Exponential 4 model (due to estimated model

parameters = dose groups) ; however, i nspection of scaled residuals and visual fit indicated appropriate

model fit.
1

2

Figure B

- 1

. Plot of mean response by dose (mg/m 3 1,2,3

- TMB) for

increased latency to pawlick in male Wistar rats , with fitted curve for

Linear model (BMR = 1 SD, modeled variance, high dose dropped)

. ( Korsak et al., 2000b )This document is a draft for review purposes only and does not constitute Agency policy.
10 DRAFT

— DO NOT CITE OR QUOTE Table B

- 4

. Model pr edictions ( constant variance ) for decreased segmented neutrophils in male Wistar rats, 1,2,3

- TMB. ( Korsak et al.,

2000b )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 0.7155 189.1052 915.77 534.809 Of the models that provided an adequate fit and

valid BMDL
estimate, the Exponential 2

model was selected

based on the

lowest AIC (BMDLs differed by less

than 3

- fold). Exponential 4 0.4482 191.0108 814.879 261.734

Exponential 5 b N / A 192.4867 547.805 137.551

Hill b N / A 192.486705 564.348 Not calculated

Linear Polynomial 2° Polynomial 3°

Power 0.6711 189.233222 979.089 632.777

a Constant variance case presented (Test 2 p

- value = 0.2692). Selected model in bold; scaled residuals for
selected model for concentrations 0, 123

, 492 and 1230 mg/m 3 were

- 0.242, 0.5701,

- 0.4994, 0.176

, respectively

. b A goodness

- of

- fit p

- value was not calculated for the Exponential 5 or Hill models, inspection of scaled residuals indicated appropriate model fit ; however, inspection of visual fit indicated uncertain dose

response characteristics, and the refore, these models were excluded from consideration.

1 Figure B

- 2

. Plot of mean response by dose (mg/m 3 1,2,3

- TMB) for

decreased segmented neutrophils in male Wistar rats , with fitted curve

for Exponential 2 model (BMR = 1 SD, constant variance)

. ( Korsak et al.,

2000b )This document is a draft for review purposes only and does not constitute Agency policy.

11 DRAFT

— DO NOT CITE OR QUOTE Table B

- 5

. Model predictions ( constant variance ) for decreased segmented neutrophils in female Wistar rats, 1,2,3

- TMB. ( Korsak et al.,

2000b )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 0.6401 177.6514 517.048 334.805 Of the models that provided an adequate fit and

valid BMDL
estimate, the Hill

model was selected

based on the

lowest BMDL (BMDLs differed by

more than 3

- fold). Exponential 4 Exponential 5 0.5208 179.1714 365.397 134.354

Hill 0.5692 179.083138 337.442 99.2111

Linear Polynomial 2° Polynomial 3°

Power 0.4533 178.341743 645.521 465.309

a Constant variance case presented (Test 2 p

- value = 0.0 9252 ). Although this p

- value is less than 0.10, it

i ndicate s a marginal fit at the 95% confidence level, and therefore a constant variance is determined to adequately fit the observed variance data. S elected model in bold; scaled residuals for selected model for
concentrations 0, 12 8

, 523

, and 1269 mg/m 3 were 0. 209

, - 0. 412

, 0. 312 , and

- 0.10 8 , respectively.

Figure B

- 3

. Plot of mean response by dose (mg/m 3 1,2,3

- TMB) for decreased segmented neutrophils in female Wistar rats , with fitted

curve for Hill model (BMR = 1 SD, constant variance)

. ( Korsak et al.,

2000b )

1This document is a draft for review purposes only and does not constitute Agency policy.

12 DRAFT

— DO NOT CITE OR QUOTE Table B

- 6

. Model predictions ( constant variance ) for increased reticulocytes in male Wistar rats, 1,2,3

- TMB. ( Korsak et al., 2000b )

Model a Goodness

- of

- fit BMD 1SD

(mg/m 3 ) BMDL 1SD

(mg/m 3 ) Basis for Model

Selection p

- value AIC

Exponential 2 Exponential 3 0.2733 89.08418 1112.25 806.744 Of the models that provided an adequate fit and

valid BMDL
estimate, the

Linear model was

selected based on

the lowest AIC (BMDLs differed by

less than 3

- fold). Exponential 4 0.1397 90.67033 900.404 308.017

Exponential 5 b N/A 91.37006 540.186 140.925

Hill N / A 91.370061 554.848 Not calculated

Linear Polynomial 2° Polynomial 3°

Power 0.3105 88.828645 1025.1 652.898

a Constant variance case presented (Test 2 p

- value = 0.5 223 ). Selected model in bold; scaled residuals for
selected model for concentrations 0, 12 8

, 523 and 1269 mg/m 3 were 0. 555

, - 1.1 4 , 0. 793, and

- 0. 2 1 2

, respectively

. b A goodness

- of

- fit p

- value was not calculated for the Exponential 5 model , inspection of scaled residuals indicated appropriate model fit ; however, inspection of visual fit indicated uncertain dose

- response characteristics, and therefore, these models were excluded from consideration.
1

2 Figure B

- 4

. Plot of mean response by dose (mg/m 3 1,2,3

- TMB) for

increased reticulocytes in male Wistar rats , with fitted curve for Linear

model (BMR = 1 SD, constant variance)

. ( Korsak et al., 2000b )This document is a draft for review purposes only and does not constitute Agency policy.

R

- 1 DRAFT

— DO NOT CITE OR QUOTE 1


# REFERENCES FOR APPENDICES 1
2

3

Korsak, Z; Rydzyński, K. (1996). Neurotoxic effects of acute and subchronic inhalation exposure to 4 trimethylbenzene isomers (pseudocumene, mesitylene, hemimellitene) in rats. Int J Occup Med 5

Environ Health 9: 341

- 349. 6

Korsak, Z; Stetkiewicz, J; Majcherek, W; Stetkiewicz, I; Jajte, J; Rydzyński, K. (2000b). Subchronic inhalation 7 toxicity of 1,2,3

- trimethylbenzene (hemimellitene) in rats. Int J Occup Med Environ Health 13: 223

- 8

232. 9

U.S. EPA. (U.S. Environmental Protection Agency). (2000). Benchmark dose technical guidance document 10 [external review draft]. (EPA/630/R

- 00/001). Washington, DC: U.S. Environmental Protection 11 Agency, Risk Assessment Forum. http://www.epa.gov/raf/publications/benchmark

- dose

- doc

12

draft.htm. 13

1 Multiple references published in the same year by the same author(s) have been assigned a letter (e.g.,

1986a , 1986b ) in Volume 1 of the Toxicological Review, based on which publication’s title comes first
alphabetically

. T hose same letters have been retained for the appendices

.