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1 DRAFT—DO NOT CITE OR QUOTE

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

Concentration range Exposure duration

IMP: 

Wistar

M 10/dose Inhalation 25-250 ppm (123-

1230 mg/m3)

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 m3 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.

Normal 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 seconds was considered as 100% inhibition of pain sensitivity.

Authors 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/m3) 18.2±5.7 11.8±3.8*

100 ppm (492 mg/m3) 27.6±3.2** 16.3±6.3***

250 ppm(1230 mg/m3) 30.1±7.9** 17.3±3.4**

250 ppm (1230 mg/m3) two weeks after 

termination of exposure 17.3±3.9 11.0±2.4

Health Effect at LOAEL NOAEL LOAEL

Decreased pain sensitivity

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 controls 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-
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2 DRAFT—DO NOT CITE OR QUOTE

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

1

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

Study Design

Species Sex N Exposure route Concentration

range

Exposure 

duration

IMP: 

Wistar

M & 

F

10/dose, 20 in 

1230mg/m3 

group

Inhalation 0, 123, 492, 1230 

mg/m3

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 m3 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/m3 exposure group, also evaluated two 

weeks after termination of exposure; blood clinical chemistry 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/m3)

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 ±0.060
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3 DRAFT—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±0.019 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/m3)

0 123 492 1230 1230a

Trend 

testb

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 (× 103/mm3)

c Males 9.49±2.03 10.25±1.29 10.11 ±1.278.05 ± 1.38* 8.6±1.5 0.0011

RBCs (× 103/mm3)

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 (× 103/mm3)

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 (× 103/mm3)

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 0.0000
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4 DRAFT—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 (× 103/mm3) 

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

Platelet (× 103/mm3) 

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/m3)

0 123 492 1230 Trend 

testb

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 0.3092
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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/m3)

[Dose group ID]

0

[1]

123

[2]

492

[3]

1230

[4]

Comparison 

to Controlsc

Trend 

testb

Proliferation of 

peribronchial lymphatic 

tissue (0-3)j Males

2.0d

(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** 0.3
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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 bronchopneumonia (0-4) Males0.5 

(20.1)

0.2 

(16.6)

0.8 

(23.8)

0.7 

(19.5) 0.3

Bronchitis and bronchopneumonia (0-4) Females0.2 

(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/m3 1230 mg/m3

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 incidences of pulmonary lesions, but 

rather the results of the Kruskall-Wallis test. This makes it difficult to interpret the doseresponse 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/m3 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

1
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7 DRAFT—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)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 5b 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). This p-value indicates that a constant 

variance model does not adequately describe the observed variances. BMDS recommends using a nonhomogenous 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)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 5b N/A 242.5858 113.028 51.9836

Hillb N/A 265.438765 334.7333 Not calculated
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8 DRAFT—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

cThe 3rd degree polynomial model failed to converge.

1
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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)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 4b 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/m3 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, inspection of scaled residuals and visual fit indicated appropriate 

model fit.

1

2

Figure B-1. Plot of mean response by dose (mg/m3 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)

 8

 10

 12

 14

 16

 18

 20

 22

 0 100 200 300 400 500

Mean Response

dose

Linear Model with 0.95 Confidence Level

13:05 03/29 2012

BMDL BMD

 

Linear
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10 DRAFT—DO NOT CITE OR QUOTE

Table B-4. Model predictions (constant variance) for decreased 

segmented neutrophils in male Wistar rats, 1,2,3-TMB. (Korsak et al., 

2000b)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 5b N/A 192.4867 547.805 137.551

Hillb 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/m3 were -0.242, 0.5701, -0.4994, 0.176, 

respectively.

bA 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 doseresponse characteristics, and therefore, these models were excluded from consideration.

1

Figure B-2. Plot of mean response by dose (mg/m3 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)

 10

 15

 20

 25

 30

 0 200 400 600 800 1000 1200

Mean Response

dose

Exponential Model 2 with 0.95 Confidence Level

09:14 04/19 2012

BMDL BMD

 

Exponential
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)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 = 0.09252). Although this p-value is less than 0.10, it 

indicates a marginal fit at the 95% confidence level, and therefore a constant variance is determined to 

adequately fit the observed variance data. Selected model in bold; scaled residuals for selected model for 

concentrations 0, 128, 523, and 1269 mg/m3 were 0.209, -0.412, 0.312, and -0.108, respectively.

Figure B-3. Plot of mean response by dose (mg/m3 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)

1

 5

 10

 15

 20

 25

 0 200 400 600 800 1000 1200

Mean Response

dose

Hill Model with 0.95 Confidence Level

09:03 04/19 2012

BMDL BMD

 

Hill
This 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)

Modela

Goodness-of-fit BMD1SD

(mg/m3)

BMDL1SD

(mg/m3)

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 5b 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 = 0.5223). Selected model in bold; scaled residuals for 

selected model for concentrations 0, 128, 523 and 1269 mg/m3 were 0.555, -1.14, 0.793, and -0.212, 

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/m3 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)

 1

 2

 3

 4

 5

 6

 0 200 400 600 800 1000 1200

Mean Response

dose

Linear Model with 0.95 Confidence Level

09:52 04/19 2012

BMDL BMD

 

Linear
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 APPENDICES12

3

4 Korsak, Z; Rydzyński, K. (1996). Neurotoxic effects of acute and subchronic inhalation exposure to 

5 trimethylbenzene isomers (pseudocumene, mesitylene, hemimellitene) in rats. Int J Occup Med 

6 Environ Health 9: 341-349. 

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

8 toxicity of 1,2,3-trimethylbenzene (hemimellitene) in rats. Int J Occup Med Environ Health 13: 223-

9 232. 

10 U.S. EPA. (U.S. Environmental Protection Agency). (2000). Benchmark dose technical guidance document 

11 [external review draft]. (EPA/630/R-00/001). Washington, DC: U.S. Environmental Protection 

12 Agency, Risk Assessment Forum. http://www.epa.gov/raf/publications/benchmark-dose-doc13 draft.htm.

 

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. Those same letters have been retained for the appendices.