Phthalic anhydride

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Remarks:

other: reproductive organs in a 2 years study were examined

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

other: well documented and scientifically acceptable

Rationale for reliability incl. deficiencies:

other: reproductive organs in a 2 years study were examined

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No hematology, urinalysis or clinical chemistry analyses were performed.

Principles of method if other than guideline:

50 male and female rats each (20 male and 20 female rats as control) were fed doses of the test substance of 0, 7.500, or 15.000 ppm (ca. 0, 500, 1000 mg/kg bw/d for 102-106 consecutive weeks, followed by sacrifice, necropsy and histopathological examination of major organs and tissues.

GLP compliance:

not specified

Specific details on test material used for the study:

Elemental analysis was performed and showed, together with the infrared spectrum, an authentic standard.

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: NCI Frederick Cancer Research Center animal farm, Maryland
- Age at study initiation: 6 weeks
- Weight at study initiation: males: 90-105 g; females: 80-95 g
- Fasting period before study: not adequate
- Housing: 4 rats per cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum, acidified to pH 2.5
- Acclimation period: 2 weeks

DETAILS OF FOOD AND WATER QUALITY:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-24°C
- Humidity (%): 45-55%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 hr per day cycle

Route of administration:

oral: feed

Vehicle:

other: diet

Details on oral exposure:

Based on prelimary studies with 7 week exposure via food, the doses for the chronic studies were determined. 10% depression in body weight was taken as the major criterion for the extimation of MTD's.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses by Frederick Cancer Research Center indicated that when phthalic anhydride was mixed with Lab Meal at a concentration of 15,000 ppm and stored at room temperature for 2 weeks, the loss was 2.59% (372 ppm) per day. Test diets containing phthalic anhydride were thus prepared fresh every 1 to 1.5 weeks. The diets were routinely stored at 5°C until used.

Duration of treatment / exposure:

105 week

Frequency of treatment:

daily

Dose / conc.:

0 ppm

Dose / conc.:

7 500 ppm

Remarks:

ca. 500 mg/kg bw/d

Dose / conc.:

15 000 ppm

Remarks:

ca. 1000 mg/kg bw/d

No. of animals per sex per dose:

50 male and 50 female rats

Control animals:

yes, concurrent no treatment

Details on study design:

Post-exposure period: no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
Daily observations for sick, tumour bearing and moribund animals, twice daily checked for deaths.
Clinical examination and palpation for masses were performed each month.

BODY WEIGHT: Yes
- Time schedule for examinations: at least once per month

Sacrifice and pathology:

At the end all animals were killed using CO2 inhalation and necropsied. Necropsies were also performed on all animals found dead, unless precluded by autolysis or severe cannibalization.

gross and microscopic examination of: skin, lungs and bronchi, trachea, bone marrow (femur), spleen, lymph nodes (mesenteric and submandibular), thymus, heart, salivary glands (patrotid, sublingual, and submaxillary), liver, pancreas, esophagus, stomach (glandular and nonglandular), small and large intestines, kidneys, urinary bladder, pituitary, adrenal, thyroid, parathyroid, pancreatic islets, testis, prostate, mammary gland, uterus, ovary, brain (cerebrum, and cerebellum), and all tissue masses. Peripheral blood smears were made for all animals, whenever possible.

Statistics:

Data recorded in an automatic data processing system, the Carcinogenesis Bioassay Data System.
Probabilities of survival were estimated by the product-limit procedure of Kaplan and Meyer (1958). A possible dose-related effect on survival was investigated with teh method of Cox (1972 and Tarone's (1975) extensions.
Incidence of neoplastic or nonneoplastic lesions is given as the ratio of animals bearing such lesions to the number without. As part of this analysis the one-tailed Fischer exact test (Cox, 1975) and other tests were used.

Description (incidence and severity):

Arched back, rough hair coat, ulceration, and corneal opacity occurred only in dosed groups, but at low incidences.

Description (incidence):

No statistical significant difference in mortality was observed in any group. Survival male rats: high-dose group 36/50 (72 %) low-dose group 44/50 (88), control group 14/20 (70 %) Survival female rats: high-dose group 41/50 (82 %), low-dose group 42/50 (84 %), control group 17/20 (85 %)

Description (incidence and severity):

The mean body weights of the high-dose males were lower than the controls from week 13 to the end of the study, but the decrease was never more than 10%. Mean body weights of the low-dose males and both the low- and high-dose females were essentially unaffected by the test compound.

Description (incidence and severity):

Severe chronic inflammatory, degenerative, or proliferative lesions frequently seen in aged rats occurred with approx. equal frequency and severity in the dosed and control groups of animals.

Description (incidence and severity):

By inspection, there appeared to be no difference between the dosed and control groups in frequency or distribution of neoplasms, except for malignant lymphoma in the female rats. The incidence in the control females was 1/20; in low-dose females 11/50; in high-dose females 4/50. Due to the high and fluctuating incidence of this type of malignant lymphoma in control F344 rats, the apparent differences in incidences of the tumor in the dosed and control groups were not considered to be compound related.

Key result

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: The NOAEL = 500 mg/kg/day, based on the reduced body-weight gain (<10%).

Critical effects observed:

no

F344 rats (50/sex/group) were fed diets containting 7500 or 15,000 ppm phthalic anhydride for 105 weeks (approx. 500 and 1,000 mg/kg bw/day). The observation that the test compound is unstable (2.59% loss of activity per day at room temperature) has to be noted, although this is of minor relevance because the diet was prepared fresh every 1 to 1-1/2 weeks and the diet was stored at 5 degree Celsius, consequently the hydrolysis is assumed to be lower than 26%.

Executive summary:

50 male and female rats each (20 male and 20 female rats as control) were fed daily doses of the test substance of 0, 7.500, or 15.000 ppm (ca. 0, 500, 1000 mg/kg bw/d for 102-106 consecutive weeks, followed by sacrifice, necropsy and histopathological examination of major organs and tissues.

The NOAEL = 500 mg/kg/day, based on the reduced body-weight gain (<10%).

reference: Huff, 1984; Kluwe, 1986; NCI, 1979

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1979

Materials and methods

Principles of method if other than guideline:

Groups of 50 rats of each sex were administered phthalic anhydride at one of 2 doses, either 7.500 or 15.000 ppm (ca. 500, 1000 mg/kg bw/d) for 105 weeks. Matched controls consisted of 20 untreated rats of each sex
At the end all animals were killed using CO2 inhalation and necropsied; gross and microscopic examination of: all major organs, including reproductive organs; in male rats preputial gland, prostate, seminal vesicle, testis and epididymis, and the mammary gland; in female rats mammary gland, uterus, endothelial gland, and ovary.

GLP compliance:

not specified

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

Phthalic anhydride

EC Number:

201-607-5

EC Name:

Phthalic anhydride

Cas Number:

85-44-9

Molecular formula:

C8H4O3

IUPAC Name:

1,3-dihydro-2-benzofuran-1,3-dione

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: diet

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

Exposure period: 105 w

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

7 500 ppm

Remarks:

ca. 500 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

15 000 ppm

Remarks:

ca.1000 mg/kg bw/day

No. of animals per sex per dose:

50 male and 50 female animals

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Remarks on result:

other:

Remarks:

Pathological examination revealed no difference between the dosed and control groups including reproductive organs; in male rats preputial gland, prostate, seminal vesicle, testis and epididymis, and the mammary gland; in female rats mammary gland, uterus, endothelial gland, and ovary.

Any other information on results incl. tables

SURVIVAL:

reduced from week 75 onwards in dosed male and female rats as well as in  controls:

high-dose males: 36/50, and females: 41/50

low-dose males: 44/50, and females: 42/50

control males: 14/20, and females: 17/20

MEAN BODYWEIGHTS (no data given):

high dose males lower than controls

high dose females and low dose males and females comparable with controls

CLINICAL SIGNS:

dosed groups: low incidences: arched back, rough hair coat, ulceration  and corneal opacity (no further details given)

PATHOLOGICAL EXAMINATION:

by inspection: no difference between the dosed and control groups

Nonneoplastic lesions on reproductive organs:

Organ   control (20)     low dose (50)      high dose (50)

Males:

preputial gland

cyst              0/20          1/50 (2%)       0/50

prostate

calculus          0/20          0/48            2/45 (4%)

inflammation, suppurative

                  0/20          2/48 (4%)       1/45 (2%)

abscess           0/20          0/48            1/45 (2%)

Inflammation, chronic

                  1/20 (5%)     0/48            0/45

inflammation, chronic suppurative

                  1/20 (5%)     0/48            0/45

fibrosis          0             1/48 (2%)       0/45

hyperblasia, focal1/20 (5%)     0/48            0/45

seminal vesicle

inflammation, suppurative

                  1/20 (5%)     0/50            0/50

testis

hemorrhage        0/20          0/50            1/50 (2%)

infarct           0/20          1/50 (2%)       0/50

atrophy           0/20          3/50 (6%)       2/50 (4%)

epididymis

inflammation, chronic

                  0/20          0/50           1/50 (2%)

mammary gland

dilatation/ducts  5/20 (25%)    12/50 (24%)    12/50 (24%)

Females:

mammary gland          20            50          50

 dilatation/ducts     13 (65%)      33 (66%)    24 (48%)

 galactccele           1 (5%)        4 (8%)      1 (2%)

 inflammation, granulomatous 0       1 (2%)     0          

 fibrosis              0             0           1 (2%)

 hyperplasia, Nos      0             0           1 (2%)

 hyperplasia, focal    1 (5%)        0           0

 hyperplasia, cystic   0             0           1 (2%)

uterus                 19            47          50

 hematoma              0             0           1 (2%)

 dilatation, nos       0             1 (2%)      0

     necrosis, nos     1 (5%)        0           0

uterus/endometrium     19            47           50

 dilatation, nos       0             1 (2%)       1 (2%)

 cysti, nos            0             1 (2%)       0

 hyperplasia, epithelial             1 (2%)       0

endothelial gland      19            47           50

 dilatation, nos       3 (16%)       0            0

ovary                  19            47           50

 cyst, nos             1 (5%)        3 (6%)       1 (2%)

 inflamation, chronic  1 (5%)        0            0

 hypoplasia, nos       0             1 (2%)       0

NOAEL: 15000 ppm.

Applicant's summary and conclusion

Conclusions:

Groups of 50 rats of each sex were administered phthalic anhydride at one of 2 doses, either 7.500 or 15.000 ppm (ca. 500, 1000 mg/kg bw/d) for 105 weeks. Matched controls consisted of 20 untreated rats of each sex
At the end all animals were killed using CO2 inhalation and necropsied; gross and microscopic examination of: all major organs, including reproductive organs; in male rats preputial gland, prostate, seminal vesicle, testis and epididymis, and the mammary gland; in female rats mammary gland, uterus, endothelial gland, and ovary.
The NOAEL = 1000 mg/kg bw/day (rats, m+f), the pathological examination revealed no difference between the dosed and control groups

Reference: Huff, 1984; Kluwe, 1986; NCI, 1979

Executive summary:

Groups of 50 rats of each sex were administered phthalic anhydride at one of 2 doses, either 7.500 or 15.000 ppm (ca. 500, 1000 mg/kg bw/d) for 105 weeks. Matched controls consisted of 20 untreated rats of each sex

At the end all animals were killed using CO2 inhalation and necropsied; gross and microscopic examination of: all major organs, including reproductive organs; in male rats preputial gland, prostate, seminal vesicle, testis and epididymis, and the mammary gland; in female rats mammary gland, uterus, endothelial gland, and ovary.

The NOAEL = 1000 mg/kg bw/day (rats, m+f), the pathological examination revealed no difference between the dosed and control groups

Reference: Huff, 1984; Kluwe, 1986; NCI, 1979