1,4-naphthoquinone

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

No methods have been provided in the literature.

GLP compliance:

not specified

Species:

rat

Strain:

not specified

Sex:

male

Sex:

male

Dose descriptor:

LD50

Effect level:

190 mg/kg bw

Based on:

not specified

Male white rats (168 to 185 g) were given the substance orally as an oily solution at doses of 100, 150, 200, 250 and 300 mg/kg body weight. The LD50 was 190 (160 to 220) mg/kg body weight. In all cases postmortems revealed congestion of the internal organs, necrosis and haemorrhages of the gastric mucosa, blurring of the border between the cortex and the medulla of the kidney and in some cases "nutmeg liver" and the accumulation of gas in the small and large intestine.

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

LD50= 190 mg/ kg bw

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

190 mg/kg bw

Quality of whole database:

2

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1993

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

performed in 1981

GLP compliance:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Duration of exposure:

4 h

The acute inhalation toxicity of 95.8% pure 1,4 -naphthoquinone was studied in accordance with OECD guideline No. 403. Groups of 5 male and 5 female Sprague Dawley rats (initial weight ca. 200 g) were exposed to 1,4 -naphthoquinone as a solid aerosol by inhalation at analytically determined concentrations of 0.065, 0.036 and 0.021 mg/l air for 4 hours (whole body exposure) with an observation period of 14 days The mean aerodvnamic particle diameter was 3.8 to 4.2 µm anel the respirable fraction <6 µm) was between 64.4 and 69.8%. During exposure, signs of irritation of the eyes and respiratory tract, which continued into the observation period, were seen in all concentration groups. Clouding of the cornea developed in 5/17 surviving animals in the intermediat and low concentration groups. Feed and water consumption was decreased for up to 7 and 5 days after exposure, respectively. Body weight declined for up to 5 days after exposure and the weight of the surviving rats did not reach that of the control animals again by the end of the observation period, except in the low concentration group. Post-mortems revealed congestion of the lungs, which were mottled in places, and histological examination showed vacuolisation and necrotic foci in the liver cells. The LC50 values were 0.039 mg/l in males, 0.053 mg/l in females and 0.046 mg/l for both sexes combined.

ormal respiration, reduction in food consumption and body weight, pale and mottled lungs, microscopic changes in lungs

(congestion), livers (hepatocyte vacuolisation, necrosis, congestion/dilatation) and kidneys (tubular basophilia, dilatation of tubular lumen).

Interpretation of results:

Category 1 based on GHS criteria

Conclusions:

LC 50=0.046 mg/l

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

46 mg/m³