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Carcinogenicity

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Description of key information

The carcinogenic potential of 1, 2, 3-trichloropropane was tested in rat and mouse by administering the chemical via gavage for 104 weeks. Testing was done according to a guideline similar to OECD451.
Cancer in multiple tissues was observed in both rats and mice. Target organs in the rats of both sexes were the forestomach and the oral mucosa. Additionally, female rats had an increased incidence of mammary gland and clitoral gland tumors while male rats had an increased incidence of tumors in the pancreas, kidney and preputial gland. The forestomach was also a target organ in mice with additional tumors observed the liver and Harderian gland.

Carcinogenicity: via oral route (target organ):digestive: pancreas; glandular: mammary gland; glandular: other; urogenital: kidneys


Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Referenceopen allclose all

Endpoint:
carcinogenicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06/1985 (first dose)-06/1987 (necropsy)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study is according to GLP and follows guideline equivalent to the OECD 451 guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 451 (Carcinogenicity Studies)
GLP compliance:
yes
Remarks:
study records audited by independent quality assurance contractor
Specific details on test material used for the study:
The test item was obtained from Shell Chemical Company. The purity of 1,2,3-trichloropropane was > 99%. No change in purity was detected throughout the study.
Species:
mouse
Strain:
B6C3F1
Sex:
male/female
Details on test animals or test system and environmental conditions:
Average temperature: 22C
Average relative humidity: 47%
Lightcycle: 12 hours on/off
Room air changes: > 10 changes an hour

The animals were held for 13/14 (male/female) days before the start of the study and the average animal age at the beginning of the study was 6 weeks old. Animals were kept in solid-bottom polycarbonate cages (1 per cage) and the cages were rotated vertically every 5 weeks. Food and water was available ad libitum.
Route of administration:
oral: gavage
Vehicle:
corn oil
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The dose formulations were analyzed periodically using gas chromatography during the study to verify the stability of 1, 2, 3-trichloropropane. The gas chromatography was performed with a flame ionization detector at 250C in a nitrogen gas carrier with a flow rate of 70 mL/minute.

No degradation of 1, 2, 3-trichloropropane was detected during the study.
Duration of treatment / exposure:
0 and 6 mg: 103 weeks (males) and 104 weeks (females)
20 mg/kg: 89 weeks
60 mg/kg: 79 weeks (males) and 73 weeks (females)
Frequency of treatment:
5 days/week
Post exposure period:
0 and 6 mg/kg bw: 8-9 days
20 and 60 mg/kg bw: 1-2 days
Remarks:
Doses / Concentrations:
0, 6, 20 and 60 mg/kg
Basis:
actual ingested
gavage
No. of animals per sex per dose:
60
Control animals:
yes, concurrent vehicle
Details on study design:
Animals of weight extremes were culled and test animals were randomly assigned to each dose group.

A total of 120 animals (60 male and 60 female) were gavaged with 1, 2, 3-trichloropropane at dose levels of either 0, 6, 20, or 60 mg/kg in corn oil (10 mL/kg). The animals were observed twice daily for clinical signs. Body weight and clinical observations were done initially weekly for the first 13 weeks and then monthly. After 15 months an interim evaluation (10 male and 10 female from each dose group) was performed including organ weight (brain, liver, and right kidney) as well as blood for hematology and clinical chemistry.

All animals were subject to necropsy and a complete histopathologic examination.
Positive control:
Not included
Observations and examinations performed and frequency:
Animals were observed twice daily. Body weight and clinical observations were done weekly for the first 13 weeks and then monthly for the remainder of the study.
Sacrifice and pathology:
A necropsy was performed on all animals. At the interim evaluation (15 months), the weight of brain, right kidney, and liver was measured. Blood for hematology and clinical chemistry was also harvested at the interim evaluation.
Statistics:
A dose-related effect on survival was analyzed by the method of Cox (Regression Models and Life Tables, J R Stat Soc B34 1972) and Tarone`s Life Table Test (Tests for Trend in Life Table Analysis, Biometrika 62 1975). These methods were also used for calculation of incidence for rapidly lethal neoplasms (survival-adjusted). Other tumors were analyzed using logistic regression.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
effects observed, treatment-related
Details on results:
All results are summarized in tables.
Dose descriptor:
dose level:
Effect level:
> 20 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Hepatocellular adenoma and carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
> 6 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Forestomach squamous cell papilloma and carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
> 20 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Harderian gland adenoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
> 60 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Oral squamous cell carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
> 6 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Uterine adenomas, adenocarcinomas and stromal polyps
Remarks on result:
other: Effect type: carcinogenicity (migrated information)

Table 1 Survival parameters

 Parameter     Vehicle control     6 mg/kg 20 mg/kg     60 mg/kg    
   Male Female  Male  Female  Male  Female  Male  Female 
Animals in study 60 60  60  60  60  60  60  60 
Animals surviving to study termination 42 41 18 13 0 0 0 0
Mean survival days 655 661 617 601 531 515 470 453

Table 2 Body weight

      Vehicle control     6 mg/kg 20 mg/kg     60 mg/kg    
 Weight in grams  Male Female  Male  Female  Male  Female  Male  Female 
 Mean bodyweight week 1 -13 25.7 22.3 25.5 (99%) 22.4(100%) 26.0(101%) 22.5(101%) 26.1 (101%) 22.8(102%)
 Mean bodyweight week 14 -52 38.0 34.9 38.3(101%) 35.6(102%) 38.9(102%) 36.6(104%) 35.8(95%) 33.8(97%)
 Mean bodyweight 53 -104 44.8 41.8 44.0(98%) 42.5(102%) 45.5(101%) 43.0(101%) 39.8(88%) 36.2(85%)

Table 3 Neoplastic effects

      Vehicle control     6 mg/kg 20 mg/kg     60 mg/kg    
Neoplastic effect  Male Female  Male  Female  Male  Female  Male  Female 
Forestomach sq. cell papilloma 3/52 0/50 28/51 23/50 22/54 18/51 33/56 29/55
Forestomach sq. cell carcinoma 0/52 0/50 40/51 46/50 50/54 49/51 51/56 49/55
Hepatocellular adenoma 11/52 6/50 18/51 9/50 21/54 8/51 29/56 31/55
Hepatocellular adenoma or carcinoma 13/52 7/50 24/51 11/50 24/54 8/51 31/56 31/55
Harderian gland adenoma 1/52 2/50 2/51 6/50 10/54 7/51 11/56  10/55
Oral sq. cell carcinoma - 0/50 - 0/50 - 1/51 - 5/55
Uterus adenoma - 0/50 - 1/50 - 0/51 - 3/55
Uterus adenocarcinoma - 0/50 - 4/50 - 3/51 - 6/55
Uterus stromal polyp - 0/50 - 2/50 - 1/51 - 6/55

Table 4 Nonneoplastic effects

      Vehicle control     6 mg/kg 20 mg/kg     60 mg/kg    
Effect  Male Female  Male  Female  Male  Female  Male  Female 
Forestomach sq. hyperplasia 8/52 10/50 29/51 15/49 27/54 14/51 34/56 31/55
Liver eosinophilic focus 2/52 0/50 3/51 6/50 8/54 9/51 32/56 34/55

Table 5 Haematology 15 month evaluation

      Vehicle control     6 mg/kg 20 mg/kg     60 mg/kg    
 Male Female  Male  Female  Male  Female  Male  Female 
Hematocrit 44.8±0.4 45.4±0.4 44.1±0.5 44.2±0.9 42.4±1.0* 43.6±0.5* 40.1±2.4** 40.4±2.0**
Hemoglobin 15.4±0.1 15.9±0.3 15.4±0.2 15.2±0.3 14.9±0.4 14.9±0.2** 13.8±0.8* 14.0±0.7**
Erythrocytes 9.28±0.05 9.57±0.09 9.46±0.09 9.11±0.42 9.29±0.26 9.09±0.10** 8.36±0.54 8.32±0.52**
Mean cell volume 48.3±0.4 47.3±0.2 46.7±0.2** 49.3±2.2 45.9±1.1** 48.0±0.3 48.4±1.5 49.0±1.1
Mean cell hemoglobin 16.6±0.1 16.6±0.2 16.2±0.1 17.0±0.7 16.1±0.4 16.4±0.1 16.5±0.5 16.9±0.3
Mean cell hemoglobin conc. 34.4±0.2 35.0±0.4 34.8±0.3 34.5±0.2 35.2±0.3 34.2±0.2 34.3±0.2 34.7±0.2
Leukocytes 6.29±0.37 4.89±0.56 4.49±0.48 5.13±0.48e 8.96±3.17 6.23±0.65* 22.38±8.16 11.22±1.26**
Segmented neutrophils 1.75±0.30 1.10±0.14 1.64±0.48 1.40±0.20e 4.56±2.22 2.30±0.28** 16.99±7.43 5.14±1.05**
Lymphocytes 4.17±0.35 3.61±0.47 2.65±0.43 3.85±0.41 4.00±0.84 3.68±0.38 4.63±0.76 5.69±0.44**
 Monocytes 0.12±0.04  0.07±0.01 0.04±0.02   0.06±0.02 e  0.13±0.05   0.10±0.03   0.10±0.07   0.15±0.02**
 Eosinophils 0.25±0.06 0.12±0.02 0.15±0.03   0.10±0.02 e  0.27±0.10   0.15±0.05   0.23±0.08   0.19±0.08
 Nucleated erythrocytes0.04 0.04±0.02 0.03±0.01 0.01±0.01   0.01±0.01   0.01±0.01   0.01± 0.01  0.01±0.01   0.02±0.02  

*Significantly different p<0.05

**Significantly different p<0.01

e: n=9

Table 6 Clinical chemistry

      Vehicle control     6 mg/ kg     20 mg/kg     60 mg/kg
 Male  Female Male  Female  Male  Female  Male  Female 
Alkaline phosphatase 45±1b 99±8   51±3b   118±15f   45±4  105±7   44±6   89±10 
Alanine aminotransferase 37±4 33 4 32±3 24±2  149±56  34±7  79±31  38± 2
Aspartate aminotransferase 68 4 101±18 79±15 67± 6 222±101   87±8   107±25   79± 6
Creatine kinase 96±12b 70±11 132±47  99±19f 186±47c   149 35*   322±84*   97 ± 20  
Lactate dehydrogenase 435±34 432±85 348±38  311 29   900±221*   474±65   956±354   433±98  
Sorbitol dehydrogenase 32±1 22±3g 28±2   22±1h  30± 4 24±1i  36±2d  38±3*d 
5 -nucleotidase 21.35±0.92b 78.70±4.38 17.86±1.08   75.44± 3.72 21.60±1.63c   73.89±2.86 27.75±4.99   66.40±6.23  

* p<0.01

b n=8

d n=3

g n=6

f n=10

h n=7

i n=4

Conclusions:
There is clear evidence of carcinogenic activity of 1, 2, 3-trichloropropane in male and female mice
Executive summary:

The main 2 -year carcinogenicity study was preceded by a 17 week exposure study to determine dose levels. A total of 40 animals (20 male and 20 female) were dosed with either 8, 16, 32, 63, 125, or 250 mg/kg 1, 2, 3 -trichloropropane in 10 mL/kg corn oil. The control group consisted of 30 males and 30 females and received only vehicle. In the two highest dose levels, deaths and lesions of the forestomach, lung, and liver were observed. The highest dose for the main study was selected to be 60 mg/kg bw.

Male and female mice of a B6C3F1 background were gavaged with 1, 2, 3 -trichloropropane 5 days per week for 2 years. The dose of 1, 2, 3 -trichloropropane given to 60 male and 60 female mice were either 0, 6, 20, or 60 mg/kg bw. After 15 months, 10 animals of each sex from each dose group was sacrificed at 15 months. Blood was taken from these animals for hematology and clinical chemistry. In addition, the brain, right kidney, and liver were weighed. At the end of the study, all animals were subject to necropsy and a full histopathologic examination.

Administration of 1, 2, 3 -trichloropropane caused a clear carcinogenic response in mice at all dose levels. The following neoplasms were observed: forestomach squamous cell papilloma/carcinoma, liver adenoma/carcinoma, harderian gland adenoma, oral squamous cells carcinoma and uterus adenoma/adenocarcinoma/stromal polyp. Additional nonneoplastic lesions related to exposure to 1, 2, 3 -trichloropropane were also observed. These include squamous hyperplasia of the forestomach and eosinophilic foci in the liver.

Endpoint:
carcinogenicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06/1985 (first dose) to 06/1987 (necropsy)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study is according to GLP and follows guideline equivalent to the OECD 451 guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 451 (Carcinogenicity Studies)
GLP compliance:
yes
Remarks:
study records audited by independent quality assurance contractor
Specific details on test material used for the study:
The test item was obtained from Shell Chemical Company. The purity of 1,2,3-trichloropropane was > 99%. No change in purity was detected throughout the study.
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals or test system and environmental conditions:
Average temperature: 22-23C
Average relative humidity: 48%
Light cycle: 12 hours on/off
Air changes: 10 changes/hour

The animals were observed for 10/14 (male/female) days before the start of the study and the average age the beginning of the study was 6 weeks old.. Animals were kept in solid-bottom polycarbonate cages (5 per cage) and the cages were rotated vertically every 5 weeks. Food and water was available ad libitum.

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
Animals were administered 1, 2, 3-trichloropropane per gavage 5 days per week. The concentration of corn oil was 5 mL/kg.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The dose formulations were analyzed periodically using gas chromatography during the study to verify the stability of 1, 2, 3-trichloropropane. The gas chromatography was performed with a flame ionization detector at 250C in a nitrogen gas carrier with a flow rate of 70 mL/minute.

No degradation of 1, 2, 3-trichloropropane was detected during the study.
Duration of treatment / exposure:
0, 3, and 10 mg/kg: 103 weeks (males) and 104 weeks (females)
30 mg/kg: 77 weeks (males) and 67 weeks (females)
Frequency of treatment:
5 days per week.
Post exposure period:
Males 0, 3. and 10 mg/kg: 10-18 days
Females 0, 3, and 10 mg/kg: 8-14 days
Male and female 30 mg/kg: 0-1 day

Males
0, 3, and 10 mg/kg: 22.05.1987 to 01-09.06.1987
30 mg/kg: 17.11.1986 to 18.11.1986

Females
0, 3, and 10 mg/kg: 02.06.1987 to 10-16.06.1987
30 mg/kg: 11.09.1986 to 10-12.09.1986
Remarks:
Doses / Concentrations:
0, 3, 10 and 30 mg/kg
Basis:
actual ingested
gavage
No. of animals per sex per dose:
60
Control animals:
yes, concurrent vehicle
Details on study design:
Animals of weight extremes were culled and test animals were randomly assigned to each dose group.

A total of 120 animals (60 male and 60 female) were gavaged with 1, 2, 3-trichloropropane at dose levels of either 0, 3, 10, or 30 mg/kg in corn oil (5 mL/kg). The animals were observed twice daily for clinical signs. Body weight and clinical observations were done initially weekly for the first 13 weeks and then monthly. After 15 months an interim evaluation (10 male and 10 female from each dose group) was performed including organ weight (brain, liver, and right kidney) as well as blood for hematology and clinical chemistry.

All animals were subject to necropsy and a complete histopathologic examination.
Positive control:
Not included in the study
Observations and examinations performed and frequency:
Animals were observed twice daily. Clinical observations and body weight was done weekly until week 13 and then monthly thereafter.
Sacrifice and pathology:
A necropsy was performed on all animals. At the interim evaluation (15 months), the weight of brain, right kidney, and liver was measured. Blood for hematology and clinical chemistry was also harvested at the interim evaluation.

All animals were also subject to a full histopathologic evaluation with the following tissues examined:
adrenal gland, bone and bone marrow, brain, clitoral gland, epididymis, esophagus, gallbladder, heart, kidney, large intestine (cecum, colon, rectum),
liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas (islets), parathyroid gland, pituitary gland, preputial
gland, prostate gland, salivary gland, seminal vesicles, skin, small intestine (duodenum, jejunum, ileum), spleen, stomach (forestomach, glandular), testes, thymus, thyroid gland, trachea, urinary bladder, and uterus.
Statistics:
A dose-related effect on survival was analyzed by the method of Cox (Regression Models and Life Tables, J R Stat Soc B34 1972) and Tarone`s Life Table Test (Tests for Trend in Life Table Analysis, Biometrika 62 1975). These methods were also used for calculation of incidence for rapidly lethal neoplasms (survival-adjusted). Other tumors were analyzed using logistic regression.

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
effects observed, treatment-related
Dose descriptor:
dose level:
Effect level:
>= 10 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Oral squamous cell papilloma and carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 3 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Forestomach squamous cell papilloma and carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 30
Sex:
male/female
Basis for effect level:
other: Zymbal`s gland carcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 10 mg/kg bw/day (actual dose received)
Sex:
male
Basis for effect level:
other: Kidney renal tubule adenoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 3 mg/kg bw/day (actual dose received)
Sex:
male
Basis for effect level:
other: Pancreas acinar adenoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 30 mg/kg bw/day (actual dose received)
Sex:
male
Basis for effect level:
other: Preputial gland adenoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 10 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Clitoral gland adenoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
dose level:
Effect level:
>= 10 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Mammary gland adenomcarcinoma
Remarks on result:
other: Effect type: carcinogenicity (migrated information)

Table 1 Survival rates

 Parameter     Vehicle control     3 mg/kg 10 mg/kg     30 mg/kg    
   Male Female  Male  Female  Male  Female  Male  Female 
Animals in study 60 60  60  60  60  60  60  60 
Animals surviving to study termination 34 31 32 30 14 8 0 0
Mean survival days 647 649 661 654 596 580 465 366

Table 2 Body weight

      Vehicle control     3 mg/kg 10 mg/kg     30 mg/kg    
 Weight in grams  Male Female  Male  Female  Male  Female  Male  Female 
 Mean bodyweight (week 1 -13)  271 170 274 (101%) 172 (101%) 275 (101%) 171 (100%) 271 (100%) 168 (99%)
 Mean bodyweight (week 14 -52)  418 217 420 (100%) 223 (103%) 420 (100%) 220 (101%) 406 (97%) 214 (99%)
 Mean bodyweight (week 53 -102)  467 287 462 (99%)  296 (103%) 462 (99%) 286 (100%) 440 (94%) 244 (85%)

Table 3 Neoplastic effects

      Vehicle control     3 mg/kg 10 mg/kg     30 mg/kg    
Neoplastic effect  Male Female  Male  Female  Male  Female  Male  Female 
Oral sq. cell papilloma 0/50 1/50 4/50 5/49 9/49 10/52 19/52 18/52
Oral sq. cell carcinoma 1/50 0/50 0/50 1/49 11/49 21/52 25/52 21/52
Forestomach sq. cell papilloma 0/50 0/50 29/50 13/49 33/49 32/51 38/52 16/52
Forestomach sq cell carcinoma  0/50  0/50  9/50 3/49  27/49  9/51  13/52  4/52 
Kidney renal tubule adenoma 0/50   - 2/50  20/49  21/52 
Preputial gland adenoma 5/49  - 3/47  5/49  11/50 
Preputial gland carcinoma 0/49   - 3/47  3/49   - 5/50 
Zymbal's gland carcinoma 0/50   0/50 0/50  1/49  0/49  0/52  3/52  3/52 
Pancreas acinar adenoma 5/50   - 21/50   - 36/49   - 29/52 
Clitoral gland adenoma  - 5/46  10/46  13/50  10/51 
Clitoral gland carcinoma  -  0/46 0/46  4/50  6/51 
Mammary gland adenocarcinoma   - 1/50  6/49  12/52  21/52 

Table 4 Non neoplastic effects

      Vehicle control     3 mg/kg 10 mg/kg     30 mg/kg    
Effect  Male Female  Male  Female  Male  Female  Male  Female 
Forestomach basal cell hyperplasia 0/50 0/50 5/50 8/49 8/49 4/51 7/52 6/52
Forestomach sq. hyperplasia 3/50 1/50 28/50 25/49 13/49 11/51 6/52 15/52
Pancreas acinar hyperplasia 28/50 5/50 46/50 14/49 46/49 24/52 48/52 9/52
Kidney renal tubule hyperplasia  0/50 0/50 1/50 2/47 21/49 3/52  29/52  10/51
Preputial gland 0/49  - 0/47 - 1/49 - 1/50 -
Clitoral gland focal hyperplasia - 0/46 - 2/46 - 3/50 3/51

Table 5 Haematology 15 month evaluation

      Vehicle control     3 mg/kg 10 mg/kg     30 mg/kg    
 Male Female  Male  Female  Male  Female  Male  Female 
Hematocrit 46.4±0.5 43.4±0.2 44.8±0.3 45.3±0.7 46.0±0.9 43.1±0.4 44.2±0.5 40.4±1.3*
Hemoglobin 16.7±0.2 15.5±0.1 16.1±0.1** 15.6±0.2 16.6±0.4 15.3±0.1 16.0±0.2* 14.5±0.5
Erythrocytes 9.32±0.11 7.83±0.06 9.09±0.14 7.89±0.16 9.45±0.18 7.99±0.08 9.09±0.14 7.39±0.35
Mean cell volume 49.8±0.6 55.3±0.3 49.3±0.5 55.2±0.5 48.8±0.4 54.0±0.2** 48.6±0.4 55.0±1.2
Mean cell hemoglobin 17.9±0.2 19.8±0.1 17.8±0.3 19.8±0.02 17.5±0.1 19.2±0.2** 17.6±0.1 19.3±0.3*b
Mean cell hemoglobin conc. 36.0±0.4 35.8±0.1 36.0 ±0.3 35.9±0.2 36.0±0.2 35.6±0.3 36.2±0.2 35.9±0.2
Leukocytes 6.62±0.24 4.23±0.24 7.61±0.39 4.56±0.28 8.00 ±0.61 4.47±0.30 9.14±0.92** 7.31±0.73**
Segmented neutrophils 1.71±0.12 1.08±0.06 2.01±0.23 1.22±0.23 2.67±0.45 1.38±0.20 3.68±0.97** 3.36±0.74**
Lymphocytes 4.56±0.28 3.02±0.22 5.34±0.27 3.18±0.14 4.98±0.24 2.88±0.18 5.03±0.24 3.76±0.20*
 Monocytes 0.18±0.05 0.08±0.02 0.14±0.03  0.11±0.03 0.25±0.04  0.10±0.03   0.25±0.07  0.11±0.03
 Eosinophils 0.15±0.03 0.04±0.01 0.12±0.02  0.04±0.01   0.09±0.04   0.10±0.02*   0.17±0.04  0.06±0.01
 Nucleated erythrocytes 0.04±0.01 0.03±0.01 0.04±0.01   0.13±0.04*   0.06±0.02   0.10±0.05   0.07±0.04  0.13±0.03* 

*p< 0.05

**p<0.01

b: n=6

 Table 6 Clinical Chemistry 15 month evaluation

      Vehicle control     3 mg/ kg     10 mg/kg     30 mg/kg
 Male  Female Male  Female  Male  Female  Male  Female 
Alkaline phosphatase 208±14 174±11   199±11   201±11   206±8   190±23   198±16   198±15  
Alanine aminotransferase 99±11 58±3 91±5   57±3   90±11   110±7   68±3*   66±10  
Aspartate aminotransferase 160±17 108±9 163±11   97±8   138±12   110±10   128±18   102±9  
Creatine kinase 639±99 462±56 602±53   484±93 665±47   587±71   665±48   384±75  
Lactate dehydrogenase 1066±125 583±82 1253±106   750±117   1225±93   917±95   1200±76   632±99  
Sorbitol dehydrogenase 18±2 11±1 19±2   12±1   20±3   17±4   18±1   16±2  
5 -nucleotidase 39.90±1.52 29.50±1.19 40.00±1.54   30.60±0.62   37.90±0.84   31.38±1.36 34.63±1.22*   31.50±1.67  

 * p< 0.01

Conclusions:
There is clear evidence of carcinogenic activity of 1, 2, 3-trichloropropane in male and female rats.
Executive summary:

The 2 -year carcinogenicity study was preceded by a 17 week exposure to determine dose levels. A total of 40 animals (20 male and 20 female) received either 8, 16, 32, 63, 125, or 250 mg/kg bw of 1, 2, 3 -trichloropropane in 5 mL/kg corn oil. The control group only received corn oil and consisted of 30 males and 30 females. The highest dose for the 2 -year study was selected based on reduced body weight and body weight gain in animals receiving 63 mg/kg bw and deaths and lesions of the liver/kidney at 125 and 250 mg/kg bw.

Male and female rats of a F344/N background were gavaged with 1, 2, 3 -trichloropropane 5 days per week for 2 years. The dose of 1, 2, 3 -trichloropropane given to 60 male and 60 female rats were either 0, 3, 10, or 30 mg/kg bw. After 15 months, 10 animals of each sex from each dose group was sacrificed. Blood was taken from these animals for hematology and clinical chemistry. In addition, the brain, right kidney, and liver were weighed. At the end of the study, all animals were subject to necropsy and a full histopathologic examination.

Administration of 1, 2, 3 -trichloropropane caused a clear carcinogenic response in rats at all dose levels. The following neoplasms were observed: squamous cell papilloma/carcinoma of the forestomach and the oral cavity, kidney renal tubule adenoma, adenoma and carcinoma of the preputial and clitoral gland, Zymbal's gland carcinoma, and mammary gland adenomcarcinoma. Additional nonneoplastic lesions related to exposure to 1, 2, 3 -trichloropropane were also observed. These include nephropathy, forestomach basal cell and squamous hyperplasia, pancreatic acinar hyperplasia, and renal tubule/preputial gland/clitoral gland hyperplasia.

Tumors were seen in various organs at the lowest dose (3 mg/kg bw).

The most sensitive endpoint in both species was the forestomach. Other significant increases in tumors were also seen at this dose for oral sq. cell papilloma, forestomach sq. cell papilloma, forestomach sq cell carcinoma, preputial gland carcinoma, pancreas acinar adenoma, clitoral gland adenoma, mammary gland adenocarcinoma.

The relevance of these tumors for the situation of human exposure needs to be differentiated as exposure via oral gavage leads to very high concentrations of 1,2,3-trichloropropane at the portal of entry (oral cavity and gastrointestinal tract). Irritation might play a major role here. Therefore the effects seen in the oral cavity, the forestomach and the pancreas are disproportional as compared to systemic effects at the respective dose. Therefore the increased number of mammary gland adenocarcinoma is regarded as the most critical systemic carcinogenic effect of 1,2,3-trichloropropene indicative for humans exposed to low concentrations or doses of 1,2,3-trichloropropane.

Based on this assumption the start value T25 is calculated to be 5.12 mg/kg bw/d.

Genotoxicity studies done on 1, 2, 3 -trichloropropane indicate that it causes both gene mutations in bacterial and mammalian systems as well as chromosome aberrations.

The incidence of mammary gland adenocarcinoma in rats at 3 mg/kg bw was 6/49 = 12.2 % as compared to 1/ 50 in the control group. So the NOAEL for carcinogenicity is 3.0 mg/Kg bw/d. This finding is the basis for the calculation of a T25 value:

3 mg/kg bodyweight dosed 5 days per week= 3 mg/kg x 5 days/7 days = 2.14 mg/kg bw/day

T25 = (25 %/X) x 2.14 mg/kg bw

X = ((6/49-1/50) / (1-1/50)) x 100 % = 10.454 %

T25 = 5.12 mg/kg bw/d

 

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
T25
5.12 mg/kg bw/day
Study duration:
chronic
System:
other: gastrointestinal tract, glandular, urogenital
Organ:
kidney
mammary gland
pancreas

Justification for classification or non-classification

The results of the 2-year carcinogenicity study by NTP are unambiguous, showing the carcinogenicity of 1,2,3-trichloropropane in both mice and rats, where rats are more susceptible. Therefore 1,2,3 -trichloropropane is to be classified as Category 1B (Warning; H350: May cause cancer)according to CLP (REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL) as implementation of UN-GHS in the EU.

This classification is in-line with the assessments of IARC ( IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 63, Dry Cleaning, Some Chlorinated Solvents and Other Industrial Chemicals, 1995, IARC Lyon, France, p. 223 -242; http://monographs.iarc.fr/ENG/Monographs/PDFs/index.php) and SCOEL (Recommendation from the Scientific Committee on Occupational Exposure Limits for 1,2,3-trichloropropane, SCOEL/SUM/170, November 2009, For public consultation).

(Category 1B, presumed to have carcinogenic potential for humans, classification is based on animal evidence.)

Additional information

A tumorigenic effect was observed in rats and mice following long-term exposure to 1, 2, 3 -trichloropropane. Many of the effects were observed at the lowest dose studied (ca 10% of predicted maximum tolerable dose) and in a dose-dependent manner. The most sensitive endpoint in both species was the forestomach. Other significant increases in tumors were also seen at this dose for oral sq. cell papilloma, forestomach sq. cell papilloma, forestomach sq cell carcinoma, preputial gland carcinoma, pancreas acinar adenoma, clitoral gland adenoma, mammary gland adenocarcinoma.

The relevance of these tumors for the situation of human exposure needs to be differentiated as exposure via oral gavage leads to very high concentrations of 1,2,3-trichloropropane at the portal of entry (oral cavity and gastrointestinal tract). Irritation might play a major role here. Therefore the effects seen in the oral cavity, the forestomach and the pancreas are disproportional as compared to systemic effects at the respective dose. Therefore the increased number of mammary gland adenocarcinoma is regarded as the most critical systemic carcinogenic effect of 1,2,3-trichloropropene indicative for humans exposed to low concentrations or doses of 1,2,3-trichloropropane.

Based on this assumption the start value T25 is calculated to be 5.12 mg/kg bw/d.

Genotoxicity studies done on 1, 2, 3 -trichloropropane indicate that it causes both gene mutations in bacterial and mammalian systems as well as chromosome aberrations.

The incidence of mammary gland adenocarcinoma in rats at 3 mg/kg bw was 6/49 = 12.2 % as compared to 1/ 50 in the control group. So the NOAEL for carcinogenicity is 3.0 mg/Kg bw/d. This finding is the basis for the calculation of a T25 value:

3 mg/kg bodyweight dosed 5 days per week= 3 mg/kg x 5 days/7 days = 2.14 mg/kg bw/day

T25 = (25 %/X) x 2.14 mg/kg bw

X = ((6/49-1/50) / (1-1/50)) x 100 % = 10.454 %

T25 = 5.12 mg/kg bw/d