Aluminatesilicate

Endpoint summary

Description of key information

Oral:
LD50: > 2000 mg/kg bw for rats (RA, silicic acid, aluminium salt)
Inhalation: 
LC50: > 2.07 mg/L , 4 hours, limit test, rats (RA calcined Kaolin)
Dermal: 
LD50: > 5000 mg/kg bw for rabbit after 2 observation days (RA Silicic acid, aluminium sodium salt)

Additional information

Oral

No experimental data are available for aluminatesilicate salt regarding acute oral toxicity, but there is an acute oral study performed with the structurally related substance silicic acid, aluminium salt.

The acute oral toxicity of Silicic acid, aluminium salt was tested according to OECD guideline 423 (Colas, 2010, RL1). The test substance was administered by gavage to six female rats at a fixed dose of 2000 mg/kg bw. During the observation period of 14 days, no mortality occured and no signs of toxicity were recorded. Thus, the oral LD50 is > 2000 mg/kg bw. In accordance with OECD guideline 423, the LD50 cut-off of the test item may be considered higher than 5000 mg/kg bw for the oral route in the rat.

Inhalation

No experimental data are available for aluminatesilicate regarding acute inhalation toxicity, but there is an acute inhalation study performed with aerosolized powder of the structurally related compound M-97-009 kaolin, calcined (Engelhard Corp., 1997, RL2). Five male and five female Sprague-Dawley rats were exposed to 2.07 mg/L kaolin, calcined in the air of whole body exposure chambers for 4 hours. The mass median aerodynamic diameter was estimated to be 2.5 microns. No mortality occurred during the study. Clinical signs were ocular and nasal discharge, irregular respiration, hunched posture and hypoactivity during the exposure time. All rats recovered from these symptoms within 17 hours after exposure. Gross necropsy findings at terminal sacrifice revealed red foci on the surface of the lungs of one female. Apart from red lung discoloration consistent with CO2 inhalation (the euthanasia procedure), all other tissues and organs appeared normal. The LC50 is > 2.07 mg/l air.

Dermal

No data were located for aluminatesilicate regarding acute dermal toxicity. But there are data available for structurally related compounds for this endpoint.

After acute dermal application of 2000, 3000, 4000 and 5000 mg/kg bw of Zeolex 23A as aqueous paste to the intact skin of 4 rabbits per dose for 24 hours under occlusive conditions, no signs of systemic or organ toxicity were recorded and no deaths occured. Dermal reactions were limited to slight erythema and edema which were fully reversible at the latest within 4 days. (Woltjen and Calkins, 1978, RL2). The dermal LD50 is > 5000 mg/kg bw.

After acute dermal application of 2000 mg/kg bw of Syloid 244 as powder to the intact skin of rabbits for 24 hours under occlusive conditions, no signs of systemic or organ toxicity were recorded and no deaths occured. Not even erythemas or edemas were observed 24 and 48 hours after exposition (Calkins, 1976, RL2). The dermal LD50 is > 2000 mg/kg bw.

Other routes

Following intratracheal inoculation of 0 or 5 mg of the read across substance Indian Kaolin in 0.1 mL NaCl the pulmonary fibrogenic response of the test substance was investigated in mice over a period of 210 days. The test substance incited acute inflammatory reaction at early periods followed by macrophage reaction, proliferation of fibroblasts and formation of focal fibrotic areas comprised of thick dense reticulination (grade II). However, the fibrotic lesions in mice at 210 days were quite different to that of nodular or diffuse interstitial fibrotic lesions described in Kaolin workers (Sahu et al., 1978, RL2).

Justification for classification or non-classification

Based on the results obtained, aluminatesilicate does not fulfill the criteria to be classified for acute toxicity according to DSD (67/548/EEC) or CLP (1272/2008/EC).