Dibutyl phthalate

Endpoint summary

Description of key information

see endpoints

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)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, with certain restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

only 7-day observation period

Principles of method if other than guideline:

BASF-Test

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Gassner
- Age at study initiation: no data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
No additional data

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50%
No additional data provided

Doses:

no data

No. of animals per sex per dose:

no data

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations and weighing: body weight was determined before the start of the study for determination of dose. Animals were observed approximately 1-3 hours after dosing and then daily over a period of 7 days.
- Necropsy of survivors performed: yes; at necropsy, all rats were examined for gross pathological changes. No further details available.

Statistics:

None

Sex:

male/female

Dose descriptor:

LD50

Effect level:

6 279 mg/kg bw

Based on:

test mat.

Remarks on result:

other: the LD50 was 6279.0 mg/kg bw (calculated from 6.0 ml/kg bw assuming test substance density of 1.0465 g/ml)

Mortality:

no data

Clinical signs:

other: no data

Gross pathology:

no data

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

6 279 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: taken from EU RAR

Qualifier:

no guideline available

Principles of method if other than guideline:

no data

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

not specified

Vehicle:

not specified

Details on inhalation exposure:

for 4 hours to an aerosol of 15.68 mg DBP/L of air. Air exposed animals served as controls. Observation period was 14 days. A second delivery of DBP was tested at 12.45 and 16.27 mg/L one month later. Respirable fraction (i.e. diameter <4.7 μm) was 56.9, 64.4 and 59.9% at 15.68, 12.45 and 16.27 mg/L. In the 15.68 mg/L group 2/5 male and 3/5 female animals died, whereas no mortalities were observed in the 12.45 and 16.27 mg/L groups.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

ca. 4 h

Concentrations:

15.68 mg DBP/L of air
12.45 and 16.27 mg/L

No. of animals per sex per dose:

5

Control animals:

yes

Sex:

male/female

Dose descriptor:

LC50

Effect level:

>= 15.68 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Body weight:

ung/body weight ratios in premature decedents at 15.68 mg/L were elevated, while these ratios were lower than those of controls in males at 12.45 and 16.27 mg/L.

Due to the unusual death pattern, no LC50 value could be determined, but the LC50 value was estimated to be ≥15.68 mg/L in this study which was performed under GLP conditions. At 15.68 mg/L apart from a reduction in respiratory rate, behaviour of the rats showed no differences with control animals. Poor coat condition was seen in all surviving animals during the observation period due to excessive grooming behaviour. Lung/body weight ratios in premature decedents at 15.68 mg/L were elevated, while these ratios were lower than those of controls in males at 12.45 and 16.27 mg/L. Macroscopy of the lungs revealed red/dark foci in several animals scattered among the treatment groups. One m and one f rat exposed to 15.68 mg/L had white foci in all lung lobes. Dark red areas were seen in the lungs of 2 females at 12.45 mg/L and in 1 male and 1 female rat at 16. 27 mg/L.

Endpoint conclusion

Dose descriptor:

LC50

Value:

15 680 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Dose descriptor:

LD50

Value:

20 000 mg/kg bw

Additional information

taken from EU RAR Dibutyl phthalate (2004):

Conclusion on acute toxicity

The oral LD50 value for the rat is ≥6,300 mg/kg bw for dibutyl phthalate; the dermal LD50 is >20,000 mg/kg bw for the rabbit. With respect to inhalation the 4h LC50 for dibutyl phthalate is ≥15.68 mg/L for the rat. According to the EC criteria, dibutyl phthalate does not need to be classified on the basis of its acute toxicity.

Conclusion taken from Australian DBP Hazard Assessment (Draft, 2007) - in line with EU RAR Dibutyl phthalate (2004):

The oral LD50 value for rats is 6300 – 8000 mg/kg bw/d, the dermal LD50 for rabbits is >20000 mg/kg bw/d and the inhalational LC50 (4 h) for rats is ≥15.68 mg/L

Justification for classification or non-classification

According to the EC criteria, dibutyl phthalate does not need to be classified on the basis of its acute toxicity.