Ammonium sodium vanadium oxide

Endpoint summary

Description of key information

Key studies demonstrate acute toxicity via the oral and inhalation route, however not via the dermal route: 
Data are read-across from structural analogues, i.e. sodium trivanadium octaoxide and ammonium trivanadium octaoxide, based on inertness and similar solubility or lack thereof.
Two reliable studies by Wolf (2006a,b) were conducted with sodium trivanadium octaoxide and ammonium trivanadium octaoxide. The LD50 was determined to be 500 mg/kg bw for sodium trivanadium octaoxide and 200 mg/kg bw  for ammonium trivanadium octaoxide. Using a worst case scenerio approach, the LD50 of 200 mg/kg bw will finally be used to cover this endpoint. 
Two reliable studies by Weniger (2006a,b) were conducted with sodium trivanadium octaoxide and ammonium trivanadium octaoxide. The LC50 (male are the sensitive species) was determined to be 1.18 mg/L air (analytical) for sodium trivanadium octaoxide and 0.67 mg/L air for ammonium trivanadium octaoxide. Using a worst case scenerio approach, the LC50 of 0.67 mg/L air will finally be used to cover this endpoint. 
Two reliable studies by Bernat (2006a,b) were conducted with sodium trivanadium octaoxide and ammonium trivanadium octaoxide. The LD50 was determined to be greater than 2000 mg/kg bw  for both vanadium compounds.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

200 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

670 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Additional information

Read across

Upon dissolution, vanadium substances transform inartificial body fluids, including PBS, sweat, gastric juice and lung fluid, predominantlyto the pentavalent form,exceptin artificial lysosomal fluid; here, even pentavalent forms are converted almost completely to tetravalent species already after a short period of time (for more information on in vitro bioaccessibility testing,please refer IUCLID section 7).Thus, it can be assumed that vanadium speciation in body fluids is controlled by the conditions of the respective medium but not by the vanadium source. Thus, read-across of skin sensitisation data from soluble tetra- and pentavalent vanadium substances is justified.

a) Ammonia/ammonium (i) is ubiquitous in the environment (air, soil and water) and as part of the natural nitrogen cycle intrinsically present in the human body due to a natural background in all dietary sources, and (ii) ammonia/ammonium is a normal constituent of all body fluids. The sources of endogenous ammonium include bacterial hydrolysis of urea and other nitrogenous compounds in the intestine, the purine-nucleotide cycle, amino acid transamination in skeletal muscle, and other metabolic processes in kidneys and liver. At physiological pH, it exists mainly as ammonium ion with reference serum levels just below 35 µmol/L. Any excess ammonia is excreted as urea, which is synthesised in the liver through the urea cycle.

b) Sodium is (i) ubiquitous in the environment (air, soil and water), (ii) a key nutrient and intrinsically present in the human body due to a natural background in all dietary sources, and (iii) a normal constituent of all body fluids and a main blood mineral. Sodium is necessary for humans to maintain the balance of the physical fluids system and is required for nerve and muscle functioning. In consequence, because of the intrinsic nature of sodium as endogenous physiological compound, any skin sensitising effect of sodium is not to be expected.

As consequence, any effects observed in human health studies based on the vanadium ion and not on the cation.

Justification for selection of acute toxicity – oral endpoint
Two studies, conducted with sodiumpolyvanadate and ammoniumpolyvanadate, were used for read across to ammonium sodium vanadium oxide. The worst case value are reported in the field “effect level”.

Justification for selection of acute toxicity – inhalation endpoint
Two studies, conducted with sodiumpolyvanadate and ammoniumpolyvanadate, were used for read across to ammonium sodium vanadium oxide. The worst case value are reported in the field “effect level”.

Justification for selection of acute toxicity – dermal endpoint
Two studies, conducted with sodiumpolyvanadate and ammoniumpolyvanadate, were used for read across to ammonium sodium vanadium oxide.

Justification for classification or non-classification

The available information indicates that ammonium sodium vanadium oxide is acutely toxic via the oral and inhalation route, but not acutely toxic or harmful via the dermal route. Ammonium sodium vanadium oxide requires classification as toxic if swallowed (R25) and toxic by inhalation (R23) according to Directive67/548/EEC. Furthermore, ammonium sodium vanadium oxide requires classification as toxic if swallowed (Category 3) and toxic if inhaled (Category 3) according to Regulation (EC) 1272/2008. Classification of ammonium sodium vanadium oxide for acute toxicity via the dermal route is not required according to Directive 67/548/EEC andRegulation (EC) 1272/2008.

Specific target organ toxicant (STOT) – single exposure: oral and inhalation

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral and inhalation are not met since reversible or irreversible adverse health effects (local or/and systemic) were not observed below lethal levels in addition to this effects which were responsible for the death of the animals. Hence, classification is not required.

Specific target organ toxicant (STOT) - single exposure: dermal

The classification criteria according to Regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure dermal are not met since any adverse health effects, including reversible and irreversible, were not observed immediately or delayed after exposure.