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Toxicological information

Carcinogenicity

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Description of key information

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records
Reference
Endpoint:
carcinogenicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study meets generally accepted scientific principles For read-across justification refer to section 13.
Principles of method if other than guideline:
A bioassay for possible carcinogenicity was conducted by administering the test material in feed to Fischer 344 rats. The chemical was administered to 50 males and 50 females at low and high concentrations, for 103 weeks. Matched-control groups were composed of 20 males and 20 females. Animals were analysed for mortality, clinical signs, histopathological as well as gross pathological changes.
GLP compliance:
no
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Schmidt, Madison, Wisconsin, USA
- Weight at study initiation: 85-110 g
- Age at study initiation: 28 days
- Housing: four per cage in solid polycarbonate cages
- Diet: prepared from Wayne Lab Blox Meal (Allied Mills, Inc.) ad libitum
- Water: acidulated water ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-25°C
- Humidity (%): 45-55%
- Air changes (per hr): 15 times per hour
- Photoperiod (hrs dark / hrs light): 16/8
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): 3 times/week
- Mixing appropriate amounts with (Type of food): Wayne Lab Blox Meal (Allied Mills, Inc.)
- Storage temperature of food: 4°C
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
- Analyses were performed, using FDA methods to determine the efficiency of the mixing procedure and the stability of the test chemical in feed. Recoveries were found to be 90.3 + / -1.4% of the theoretical value at 7,500 ppm EDTA and 90.4 + / - 3.4% of the theoretical value at 3,750 ppm. It was concluded from these results that the preparations contained reasonably accurate concentrations of EDTA and were mixed homogeneously, and that the chemical was stable in feed for at least a week.
Duration of treatment / exposure:
103 weeks
Frequency of treatment:
daily
Post exposure period:
none
Remarks:
Doses / Concentrations:
248; 495 mg/kg bw/day (original data: 3,750 ppm 7,500 ppm; conversion according to EU risk assessment)
Basis:
nominal in diet
No. of animals per sex per dose:
50 (except for the control, which consisted of only 20 animals)
Control animals:
yes, plain diet
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: approximately once a month
Sacrifice and pathology:
GROSS PATHOLOGY: Yes; all major organs, not specified but presumably all organs used for histopathology: skin, lymph nodes, mammary gland, salivary gland, bone marrow, trachea, lungs and bronchi, heart, thyroids, parathyroids, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas, spleen, kidneys, adrenals, urinary bladder, prostate or uterus, testis or ovary, brain, and pituitary.
HISTOPATHOLOGY: Yes;
skin, lymph nodes, mammary gland, salivary gland, bone marrow, trachea, lungs and bronchi, heart, thyroids, parathyroids, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas, spleen, kidneys, adrenals, urinary bladder, prostate or uterus, testis or ovary, brain, and pituitary.
Statistics:
- Statistical tests of differences in survival between groups are compared using the method of Cox (1972) for two groups and an extension of this method by Tarone (1975) for more than two groups.
- Statistical analysis of the incidence of tumors was made using the Fisher exact test (Cox, 1970) to compare a control group to a group of treated animals at each dose. In addition, the Armitage and Cochran test for linear trend in proportions, with continuity correction (Armitage, 1971), was used
Histopathological findings: neoplastic:
effects observed, treatment-related
Details on results:
MORTALITY
The male rats exhibited a negative dose-related trend in survival with the probability level of P = 0.103; the treated and control groups of male rats can thus be considered as comparable to each other in survival. The female rats also exhibited a negative dose-related trend in survival, but in this case the effect was statitstically significant (p =0.029).

CLINICAL SIGNS
No significant signs were observed among test animals during the first year of the study. In the 6 months preceding termination of the test, corneal opacities, ascites, and urine stains, occurred in both treatment and control groups.

BODY WEIGHT AND WEIGHT GAIN
Average body weights of treated male and female rats were comparable to those of the matched controls throughout the study.

GOSS PATHOLOGY
Inflammatory and degenerative changes were observed in about the same frequency in all groups. These lesions appeared to be related to age and no to the administration of the chemical.

HISTOPATHOLOGY: NEOPLASTIC
A high incidence of neoplasms occurred in the reproductive and endocrine systems and lower in the hematopoietic, respiratory, integumentary, and digestive systems. No neoplasms were observed in the nervous, musculoskeletal, or urinary systems or in organs of special sense. A number of tumors occurred in other organ systems of both sexes, controls as well as treated animals.
No tumor appeared in a statistically significant positive trend in either dose groups or sexes. A variety of endocrine tumors were found, some types occurring only in treated animals. However, these tumors occurred in low numbers and have frequently been seen in untreated animals in other studies. Therefore, they are probably unrelated to treatment .
Males:
Interstitial-cell tumors of the testes were observed in nearly all male rats in each feeding group. This high incidence of interstitial-cell tumors in both treated and control animals reflects this commonly occurring age-related lesion in the male Fischer 344 rat.
Females:
The distribution of neoplasms in the reproductive system among control and treated rats was random, the tumors occurred mainly in the uterus . The majority of these were endometrial stromal polyps. However, one adenocarcinoma and one leiomyosarcoma occurred at 495 ppm. An ovarian cystadenoma was detected in a single 248 ppm-dose rat
Dose descriptor:
NOAEL
Effect level:
>= 500 mg/kg bw/day (nominal)
Sex:
male/female
Remarks on result:
other: Effect type: carcinogenicity (migrated information)
Dose descriptor:
NOAEL
Effect level:
>= 500 mg/kg bw/day (nominal)
Sex:
male/female
Remarks on result:
other: Effect type: toxicity (migrated information)

Table 1: Analyses of the Incidence of Primary Tumors at Specific Sites in Male Rats Fed EDTA Trisodium Salt in the Diet

Morphology (p-value) Control 248 mg/kg bw/day 495 mg/kg bw/day
Hematopoietic System: Leukemia, Malignant Lymphoma and Lymphocytic Leukemia 3/20 (n.s.) 4/50 (n.s.) 4/50 (n.s.)
Weeks to first observed tumor:  76 104 102
Adrenal: Pheochromocytoma 2/20 (n.s.) 5/49 (n.s.) 4/50 (n.s.)
Weeks to first observed tumor:  104 104 67
Thyroid: C-cell Adenoma 0/17 (n.s.) 6/35 (p = 0 0.08) 3/38 (n.s.)
Weeks to first observed tumor:  - 104 67
Pituitary: Chromophobe Adenoma 0/18 3/47 (n.s.) 5/44 (n.s.)
Weeks to first observed tumor:  - 88 104
Lung: Alveolar/Bronchiolar Adenoma and Carcinoma 1/18 (n.s.) 2/50 (n.s.) 3/49 (n.s.)
Weeks to first observed tumor:  104 95 67
Liver: hepatocellular Adenoma and Neoplastic Nodule 0/20 (n.s.) 1/48 (n.s.) 1/50 (n.s.)
Weeks to first observed tumor:  - 104 104
Testis: Interstitial-cell Tumor 19/20 (n.s.) 43/50 (n.s.) 44/50 (n.s.)
Weeks to first observed tumor:  88 85 95

Table 2 Analyses of the Incidence of Primary Tumors at Specific Sites in Female Rats Fed EDTA Trisodium Salt in the Diet

Morphology (p-value) Control 248 mg/kg bw/day 495 mg/kg bw/day
Hematopoietic System: Leukemia, Malignant Lymphoma and Lymphocytic Leukemia 1/20 (n.s.) 8/50 (n.s.) 0/50 (n.s.)
Weeks to first observed tumor:  104 80 -
Adrenal: Pheochromocytoma 1/20 (n.s.) 1/49 (n.s.) 1/48 (n.s.)
Weeks to first observed tumor:  98 104 104
Thyroid: C-cell Adenoma 0/11 (n.s.) 0/36 (n.s.) 1/37 (n.s.)
Weeks to first observed tumor:  - - 104
Pituitary: Chromophobe Adenoma 6/19 (n.s.) 10/48 (n.s.) 11/50 (n.s.)
Weeks to first observed tumor:  95 104 104
Lung: Alveolar/Bronchiolar Adenoma and Carcinoma 0/20 (n.s.) 3/48 (n.s.) 2/48 (n.s.)
Weeks to first observed tumor:  - 104 104
Liver: Neoplastic Nodule 0/20 (n.s.) 1/48 (n.s.) 0/48 (n.s.)
Weeks to first observed tumor:  - 104 -
Uterus: Endometrial Stromal Polyp 5/20 (n.s.) 6/50 (n.s.) 7/50 (n.s.)
Weeks to first observed tumor:  104 96 85
Mammary Gland: Fibroadenoma 4/20 (n.s.) 3/50 (n.s.) 3/50 (n.s.)
Weeks to first observed tumor:  85 96 97

- Not all animals were examined pathologically, due to cannibalism or advanced state of autolysis.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
500 mg/kg bw/day
Study duration:
chronic
Species:
rat
Quality of whole database:
Also mouse study available with a higher NOAEL.

Carcinogenicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Carcinogenicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

A study in the rat on a structural analogue of the substance revealed a high incidence of neoplasms occurring in the reproductive and endocrine systems and a lower incidence in the hematopoietic, respiratory, integumentary, and digestive systems. No neoplasms were observed in the nervous, musculoskeletal, or urinary systems or in organs of special sense. A number of tumours occurred in other organ systems of both sexes, controls as well as treated animals. No tumour appeared in a statistically significant positive trend in either dose groups or sexes. A study with the same substance in the mouse revealed a variety of neoplasms in both treated and control animals that were well known from historical controls of the same strain. There was a high incidence of tumors in the hematopoictic, endocrine, digestive, and respiratory systems. The incidence of neoplasms in other systems was variable. For all tumour types observed no statistical significance were seen between incidences in treated and control groups.


Justification for selection of carcinogenicity via oral route endpoint:
Well performed study in rats with a structurally related substances meeting generally accepted scientific principles

Justification for classification or non-classification

Negative findings were obtained in tests for gene mutation / mutagenicity. In-vivo carcinogenicity studies in the rat and mouse have not revealed any statistical significant increace in tumour type or incidence.

Non-classification is justified on the basis of negative findings in accordance with Regulation (EC) No. 1272/2008.