Chromium trioxide

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to birds: reproduction test

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Description of key information

From EU RAR (2005):
Chromium (VI) has been shown to be taken up by a wide range of organisms from water, sediment and soil. For fish, although uptake does occur, the bioconcentration factors for chromium (VI) are usually very low (~1 l/kg).
The toxicity of chromium (VI) to birds has been studied by several authors. Biswas (1985) reported an 18 day-LD50 value for chromium (VI) (as potassium dichromate) of 300 ppm for chick embryos. In the experiment, embryonated eggs were inoculated with solutions of potassium dichromate and it is not clear from the paper if the LD50 refers to the concentration of chromium in the solution given to the eggs or to the dose of chromium given to the eggs. Huu Chanh and Chanvatte (1967) investigated the toxicity of chromium (VI) (as sodium chromate) to pigeon (Columba domestica)and chicken (Gallus gallus), by intravenous injection of solutions of the chemical. The 60-minute lethal dose was found to be 101.9-111.3 mg/kg body weight for pigeon and 105.4-107.6 mg/kg body weight for chicken.
The toxicity of chromium (VI) (as sodium chromate) has been studied in a 1-year feeding study using chickens (Gallus gallus). In the study, the chickens were fed parboiled rice containing 0.7 mg Cr/kg rice. The estimated average daily intake of chromium (VI) from the treated rice was 40.9 µg/bird. The control chickens were fed non-spiked rice, and the background daily exposure to total chromium from this rice was around 3.5 µg/bird. No effects were seen over this time period on body weight, organ weights or haematological parameters, and no gross or histological changes attributable to the exposure were found in liver, spleen, kidneys, heart, lungs and gonads. Similar results were found in experiments with mice (Rao et al., 1983).
The available mammalian toxicity data are reviewed in Section 4 of the EU RAR (2005).

The most relevant results from these data are a no observed adverse effect level (NOAEL) of 20 mg Cr (VI)/kg body weight/day for effects on the testes in mouse (oral gavage route) and a LOAEL of 20 mg Cr (VI)/kg body weight/day for developmental effects in mice (drinking water route). For the purpose of this assessment the 20 mg/kg bw value is used, recognising that in one of the studies effects were seen at this level.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for birds:

20 mg/kg food