ALFERROCK

Carcinogenicity

Description of key information

No specific carcinogenicity data are available for the target substance.

In the absence of substance-specific data for Alferrock, a conservative approach to hazard evaluation is to assume that aluminium released from Alferrock shows the same systemic hazards as other aluminium compounds with similar or higher bioavailability. Read-across to aluminium compounds with a high release of aluminium ions (soluble Al salts) is considered to represent a worst-case approach that overestimates toxicological properties of the target compound. For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

 

Therefore suitable data available from the read across partner aluminium potassium sulfate were used in the assessment. A combined oral chronic and carcinogenicity toxicity study in mice (similar to EU method B.33) was conducted using aluminium potassium sulfate. No adverse effects have been reported up to 100,000 ppm in the diet (15,000 mg/kg bw/day). Additionally the treatment does not exert tumourgenicity in the study.

 

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Endpoint:

carcinogenicity: oral

Remarks:

combined repeated dose and carcinogenicity

Type of information:

experimental study

Adequacy of study:

key study

Justification for type of information:

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.33 (Combined Chronic Toxicity / Carcinogenicity Test)

Deviations:

not specified

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

The survival rates at the end of the dosing period were 73.3% (male) and 78.3% (female) in the control group, and 86.7%-95.0% (male) and 86.7-91.7% (female) in the treatment group.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Both the male and the female mice in the high dose level exhibited slight growth retardation compared with the control group after 1 month, and those in the 1.0 and 2.5 % dose groups exhibited a slight increase in body weight after 3 months. Both male and female mice receiving 5.0% test item showed growth similar to that in the control group.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Food consumption did not show any variation among the groups throughout the experimental period for either males or females.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

A significant increase in the absolute organ weight was observed in the kidneys and heart in both sexes in the 1.0, 2.5 and 5.0% dose groups, in the pituitary in the males in the 2.5% dose group and the brain in the females in the 1.0% group compared with those in the control group. Additionally, there were significant decreases in the absolute organ weight of the liver in both sexes in the 5.0 and 10.0% dose groups, the heart and brain in both sexes in the high dose group and lungs in the males and spleen in the females in the 10% high dose group compared with those in the control group. There was a significant increase in the relative organ weight of the kidneys in the males in the 5.0% dose group and a significant decrease in the relative organ weight of the liver in both sexes in 5.0 and 10% groups and spleen in the females in the high dose group.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

The incidence of myocardial eosinophilic cytoplasm showed a significant dose-dependent decrease in the male mice in the treatment groups. A comparison between the sexes revealed a significant decrease in the incidence of hepatocytic anisonucleosis, myocardial eosinophilic cytoplasm and acinar cell vacuolation of sumandibular gland in females; and lymphocyte infiltration in the renal cortex and pelvis, and vacuolation of cerebrellar white matter in the males

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

The incidence of the male tumour bearing mice was 40.9%, and 54.5, 36.5, 42.9 and 17.5% in the control group and 1.0, 2.5, 5.0 and 10.0% dose groups, respectively, while that of female tumour.bearing mice was 29.8, 23.6, 17.3, 11.5 and 13.5% respectively.

HISTORICAL DATA
The incidence of all tumours and non-tumorous changes was within the normal range reported for spontaneous changes in B6C3F1 mice.

Dose descriptor:

NOAEL

Effect level:

100 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects notified

Critical effects observed:

no

Conclusions:

In conclusion, the results of the present study indicate that long-term administration of a diet containing 10% (w/w) aluminium potassium sulfate does not exert tumorgenicity or any other toxic actions in male and female B6C3F1 mice. Thus, the NOAEL can be considered to be 100000 ppm (10 % w/w).

Executive summary:

In a chronic (20 months) combined repeated oral dose toxicity and carcinogenicity study (similar to EU method B.33) aluminium potassium sulfate dodecahydrate was administered orally via the diet to 60 male and female B6C3F1 mice at concentrations of 0, 10000, 25000, 50000 and 100000 ppm. The animals were treated with the test item 7 days per week for a period of 20 months. The treatment does not exert tumourgenicity or any other toxic action (mortality, food consumption, body weights, organ weights and histopathology) in any dose group investigated. Based on the results the chronic NOAEL for both sexes can be considered to be 100000 ppm which equals 15000 mg/kg bw/day.

This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

15 000 mg/kg bw/day

Study duration:

chronic

Species:

mouse

Quality of whole database:

Well documented chronic toxicity study with aluminium potassium sulfate (AlK(SO4)2*12H2O) used as read-across partner

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of an oral combined chronic repeated dose and carcinogenicity study with a read-across analogue substance, classification of the target substance according to the criteria set out in Annex I of Regulation (EC) 1272/2008 (CLP Regulation) is not warranted.

Additional information

For human health endpoints, the relative bioavailability of different metal-ions from ALFERROCK would determine its potential to cause toxicological effects and also govern the severity of such effects. According to the results of the bioelution testing,aluminium has the highest relative release into artificial physiological media and therefore was considered as main constituent for the human health hazard/risk assessment of Alferrock (Klawonn, 2021, please see IUCLID section 7.1.1).

No carcinogenicity data is available for the test substance. However, suitable data is available from the read across partner aluminium potassium sulfate. Due to higher water solubility of aluminium potassium sulfate compared to the aluminium release from the test substance, the resulting bioavailability of aluminium from the test substance would also be expected to be lower. Therefore, the read-across to the source substance aluminium potassium sulfate is considered adequately protective. Details on the read-across rationale are provided in section 13.

A combined oral chronic toxicity and carcinogenicity study in mice (similar to EU method B.33) was conducted using aluminium potassium sulfate. The results of the chronic toxicity study indicate that long-term administration (20 months) of a diet containing 0, 1.0, 2.5, 5.0 and 10.0% aluminium potassium sulfate (AlK(SO4)2*12H2O) does not exert tumorigenicity or any other toxic action (mortality, food consumption, body weights, organ weights and histopathology) in sixty B6C3F1 mice of each sex/dose. Therefore, the chronic NOAEL for both sexes can be considered to be 100,000 ppm in the diet which equals 15,000 mg/kg bw/day (by applying a default conversion factor of 0.15 as recommended in an EFSA guidance document).