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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
This study is used for read-across and therefore has been assigned a reliability of 2 (reliable with restrictions). The study, if used in support of terephthalic acid, has a reliability of 1 (reliable without restriction). This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment. Guideline study performed under GLP requirements.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2001
Reference Type:
secondary source
Title:
SIDS Initial Assessment Report for the 12th SIAM, Paris, France, June 2001
Author:
OECD SIDS
Year:
2001
Bibliographic source:
UNEP Publications

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Terephthalic acid was supplied by the Amoco Corporation.
Terephthalic acid, a white solid (powder), lot no. SBJ-4972, purity 99.9%. The substance was stored at room temperature, protected from light and moisture.

Test animals

Species:
mouse
Strain:
ICR
Sex:
male/female
Details on test animals and environmental conditions:
Male and female ICR mice were obtained from Harlan Sprague Dawley, Inc. in two batches. At study initiation mice were 6-8 weeks old. Pilot study mouse weights were: males 29.5-34.1 g; females 25.2-27.4 g. Micronucleus assay mouse weights were: males 25.6-30.4 g; females 23.9-28.1 g.
Mice were quarantined for 5 days. The animal room was maintained at a temperature of 72±3°F, 50±20% relative humidity and a 12 hour light/dark cycle. Mice were housed in same sex groups of 5 in polycarbonate cages on racks. Hardwood chips were used as bedding. Food (Harlan TEKLAD certified Rodent 7012C) and tap water (Washington Suburban Sanitary Commission) were provided ad libitum.
Mice were numbered and identified by ear tag.

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
Corn oil. The vehicle was chosen as it permitted preparation of the highest soluble or workable stock solution, up to 100 mg/ml (compared to 0.5% CMC in water).
Details on exposure:
Mice were given a single intraperitoneal injection of the test substance, or vehicle alone.
All mice were weighed immediately prior to dose administration and the dose volume based on individual body weights. Injections were kept to a constant volume of 20 ml/kg body weight.

Additional animals (5/sex/group) were treated with vehicle or 800 mg/kg TPA and sacrificed at 48 hours. An additional group of 5 males and 5 females were dosed with 800 mg/kg TPA as a replacement group in case of mortality.
Duration of treatment / exposure:
Pilot study & Toxicity study: mice were observed for signs of toxicity for 3 days after administration.
Micronucleus study: single injection, mice were sacrificed 24 hours later. Additional mice from the vehicle control and high dose groups were sacrificed 48 hours after dose administration.
Frequency of treatment:
Single injection
Post exposure period:
Pilot study & Toxicity study: 3 days.
Micronucleus study: 24 or 48 hours.
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
1, 10, 100, 1000 and 2000 mg/kg
Basis:
nominal conc.
Pilot study
Remarks:
Doses / Concentrations:
1200, 1400, 1600 and 1800 mg/kg
Basis:
nominal conc.
Toxicity study
Remarks:
Doses / Concentrations:
200, 400, and 800 mg/kg
Basis:
nominal conc.
Main micronucleus study
No. of animals per sex per dose:
Pilot study: 5 mice/sex received 2000 mg/kg, and 2 males/dose received either 1, 10, 100 or 1000 mg/kg.
Toxicity study: 5 mice/sex/dose
Micronucleus study: controls - 10 mice/sex; 200 and 400 mg/kg - 5 mice/sex/dose, 800 mg/kg - 15 mice/sex/per dose, positive controls - 5 mice/sex/dose.
Control animals:
yes, concurrent vehicle
Positive control(s):
In the micronucleus study, 5 males and 5 females were injected with cyclophosphamide dissolved in distilled water at a dose of 50 mg/kg.

Examinations

Tissues and cell types examined:
Bone marrow cells obtained from the femurs.
Details of tissue and slide preparation:
Immediately follow sacrifice, the femurs were exposed, cut just above the knee, and the bone marrow was aspirated into a syringe containing foetal bovine serum. The cells were transferred to a capped centrifuge tube containing approximately 1 ml foetal bovine serum. The cells were pelleted by centrifugation at 100 x g for 5 minutes and the supernatant drawn off. The cells were resuspended and a small drop of bone marrow suspension was spread onto a clean glass slide. Two slides were prepared from each mouse. The slides were fixed in methanol and stained with May-Gruenwald-Giemsa and permanently mounted. Slides were coded prior to analysis.
Evaluation criteria:
2000 polychromatic erythrocytes were scored per slide for the presence of micronuclei. The number of micronucleated normochromatic erythrocytes per 2000 polychromatic erythrocytes was recorded, and the proportion of polychromatic erythrocytes to total erythrocytes over 1000 was recorded.
The test article was considered to induce a positive response if a dose responsive increase in micronucleated polychromatic erythrocytes was observed, and one or more doses were statistically elevated relative to the vehicle control.
Statistics:
Kastenbaum-Bowman tables were used to determine statistical significance at the 5% level.

Results and discussion

Test resultsopen allclose all
Sex:
male/female
Toxicity:
yes
Remarks:
1000 mg/kg and above
Vehicle controls validity:
not examined
Negative controls validity:
not examined
Positive controls validity:
not examined
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
lethargy and piloerection at all doses
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
Pilot study: 3/5 males and 5/5 females died within 2 days administration of 2000 mg/kg. Lethargy and piloerection were noted in males at 1000 mg/kg and males and females at 2000 mg/kg. Tremors were observed in the males at 2000 mg/kg, and convulsions, prostation and crusty eyes were observed in females at this dose. All other animals appeared normal.

Toxicity study: mortality occurred within 3 days of dosing as follows: 2/5 males and 1/5 females at 1200 mg/kg; 4/5 males and 3/5 males at 1400 mg/kg; 2/5 males and 4/5 females at 1600 mg/kg; and 4/5 males and 2/5 females at 1800 mg/kg. Lethargy, piloerection and crusty eyes were seen in all mice at all doses. Tremors were seen in females at 1200 mg/kg, and in males and females at 1400 and 1800 mg/kg. Convulsions were seen in males and females at 1600 and 1800 mg/kg, and prostration in males at 1200 and 1400 mg/kg and males and females at 1600 and 1800 mg/kg. The maximum tolerated dose chosen for the micronucleus assay was 800 mg/kg.

Micronucleus study: 1 male mouse in the 800 mg/kg group was found dead the day after administration, but was replaced. Lethargy and piloerection were seen at all 3 doses in both sexes. Mice treated with vehicle alone and the positive control substance appeared normal throughout the study. Reductions of 2% to 9% in the ratio of polychromatic erythrocytes to total erythrocytes were observed in some of the treated groups compared to controls suggesting that erythropoiesis was not inhibited. There were no significant increases in the number of micronucleated polychromatic erythrocytes per 2000 polychromatic erythrocytes in treated groups compared to controls, irrespective of sex and time of bone marrow collection. The positive control substance induced a significant increase.

Any other information on results incl. tables

Administration of the test substance did not induce any increase in the incidence of micronucleated PCEs in any of the treated groups.

Summary of Bone Marrow Micronucleus Study

Treatment

Sex

Time
(hr)

Number of Mice 

PCE/Total

Change from Control (%)

Micronucleated Polychromatic Erythrocytes

Erythrocytes
(Mean +1- SD)

Number per 1000 PCEs
(Mean +1- SD)
 

Number per PCEs Scored1

Corn oil

 

 

 

 

 

 

 

20 mL/kg

M

24

5

0.456 ± 0.03

0.3 ± 0.27

3 / 10000

 

F

24

5

0.477 ± 0.06

0.1 ± 0.22

1 I 10000

Terephthalic acid

 

 

 

 

 

 

 

200 mg/kg

M

24

5

0.455 ± 0.06

0

0.4 ± 0.22

4 / 10000

 

F

24

5

0.445 ± 0.03

-7

0.4 ± 0.22

4 / 10000

400 mg/kg

M

24

5

0.474 ± 0.06

4

0.3 ± 0.27

3 / 10000

 

F

24

5

0.435 ± 0.03

-9

0.2 ± 0.27

2 / 10000

800 mg/kg

M

24

5

0.465 ± 0.04

2

0.2 ± 0.27

2 / 10000

 

F

24

5

0.467 ± 0.07

-2

0.2 ± 0.27

2 / 10000

CP

 

 

 

 

 

 

 

50 mg/kg

M

24

5

0.342 ± 0.03

-25

16.7 ± 5.73

*167 / 10000

 

F

24

5

0.339 ± 0.02

-29

21.5 ± 3.04

*215 I 10000

Corn oil

 

 

 

 

 

 

 

20 mL/kg

M

48

5

0.484 ± 0.04

0.5 ± 0.00

5 / 10000

 

F

48

5

0.463 ± 0.03

0.3 ± 0.27

3 / 10000

Terephthalic acid

 

 

 

 

 

 

 

800 mg/kg

M

48

5

0.495±0.05

2

0.0 ± 0.00

0 / 10000

 

F

48

5

0.476±0.04

3

0.2 ± 0.27

2 / 10000

1*p≤0.05 (Kastenbaum-Bowman Tables)

 

Induction of Micronucleated Polychromatic Erythrocytes in Bone Marrow Cells Collected 24 Hours After a Single Dose of Terephthalic Acid

Treatment

Sex

Animal Number

PCE/Total Erythrocytes

Micronucleated PCE
(Number/PCE scored)

Corn oil

 

 

 

 

20 mL/kg

M

101

0.446

0 / 2000

 

 

102

0.408

1 / 2000

 

 

103

0.464

1 / 2000

 

 

104

0.468

0 / 2000

 

 

105

0.493

1 / 2000

 

F

106

0.438

0 / 2000

 

 

107

0.561

1 / 2000

 

 

108

0.434

0 / 2000

 

 

109

0.438

0 / 2000

 

 

110

0.516

0 / 2000

Terephthalic acid

 

 

 

 

200 mg/kg

M

111

0.438

1 / 2000

 

 

112

0.419

1 / 2000

 

 

113

0.553

1 / 2000

 

 

114

0.428

0 / 2000

 

 

115

0.435

1 / 2000

 

F

116

0.456

0 / 2000

 

 

117

0.488

1 / 2000

 

 

118

0.441

1 / 2000

 

 

119

0.420

1 / 2000

 

 

120

0.420

1 / 2000

400 mg/kg

M

121

0.465

1 / 2000

 

 

122

0.434

0 / 2000

 

 

123

0.414

1 / 2000

 

 

124

0.566

0 / 2000

 

 

125

0.491

1 / 2000

 

F

126

0.423

0 / 2000

 

 

127

0.418

0 / 2000

 

 

128

0.413

0 / 2000

 

 

129

0.481

1 / 2000

 

 

130

0.439

1 / 2000

800 mg/kg

M

131

0.525

0 / 2000

 

 

132

0.456

0 / 2000

 

 

173*

0.408

1 / 2000

 

 

134

0.458

0 / 2000

 

 

135

0.478

1 / 2000

 

F

136

0.462

1 / 2000

 

 

137

0.388

0 / 2000

 

 

138

0.564

0 / 2000

 

 

139

0.484

1 / 2000

 

 

140

0.435

0 / 2000

CP

 

 

 

 

50 mg/kg

M

141

0.350

23 / 2000

 

 

142

0.322

30 / 2000

 

 

143

0.323

32 / 2000

 

 

144

0.333

29 / 2000

 

 

145

0.384

53 / 2000

 

F

146

0.366

34 / 2000

 

 

147

0.345

44 / 2000

 

 

148

0.315

51 / 2000

 

 

149

0.340

44 / 2000

 

 

150

0.329

42 / 2000

* Replacement animal

 

Induction of Micronucleated Polychromatic Erythrocytes in Bone Marrow Cells Collected 48 Hours After a Single Dose of Terephthalic Acid

Treatment

Sex

Animal Number

PCE/Total Erythrocytes

Micronucleated PCE
(Number/PCE scored)

Corn oil

 

 

 

 

20 mL/kg

M

151

0.472

1 / 2000

 

 

152

0.470

1 / 2000

 

 

153

0.447

1 / 2000

 

 

154

0.485

1 / 2000

 

 

155

0.544

1 / 2000

 

F

156

0.454

1 / 2000

 

 

157

0.466

1 / 2000

 

 

158

0.480

0 / 2000

 

 

159

0.425

0 / 2000

 

 

160

0.490

1 / 2000

Terephthalic acid

 

 

 

800 mg/kg

M

161

0.541

0 / 2000

 

 

162

0.454

0 / 2000

 

 

163

0.444

0 / 2000

 

 

164

0.494

0 / 2000

 

 

165

0.543

0 / 2000

 

F

166

0.439

1 / 2000

 

 

167

0.500

1 / 2000

 

 

168

0.530

0 / 2000

 

 

169

0.455

0 / 2000

 

 

170

0.458

0 / 2000

 

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
This study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).
Under the conditions of this study, the test substance did not induce a significant increase in the incidence of micronucleated polychromatic erythrocytes in bone marrow and was concluded to be negative in the mouse micronucleus test.
Executive summary:

The test substance was tested in the mouse micronucleus assay. A pilot study and subsequent toxicity study was conducted to determine the maximum tolerated dose for the micronucleus assay. The test substance was administered in corn oil by a single intraperitoneal injection, at a constant injection volume of 20 ml/kg. Based on mortality and clinical signs observed during the pilot and toxicity studies, the maximum tolerated dose set for the micronucleus study was 800 mg/kg. Clinical signs included lethargy, piloerection, tremors and crusty eyes. In the micronucleus assay, the test substance was administered i.p. at doses of 0, 200, 400 and 800 mg/kg. Bone marrow cells were harvested 24 or 48 hours later. The positive control was cyclophosphamide. No significant increase in micronucleated polychromatic erythrocytes in test article treated groups relative to vehicle controls was observed.

Under the conditions of this study, the test substance was concluded to be negative in the mouse micronucleus test.