Naphthalenesulfonic acids, branched and linear Bu derivs., sodium salts

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Rats were treated daily orally by gavage with the test item in water from day 6 to day 15 p.c.. The fetuses were delivered by cesarian section on the 20th day of gestation.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Naphthalenesulfonic acids, branched and linear Bu derivs., sodium salts

EC Number:

293-346-9

EC Name:

Naphthalenesulfonic acids, branched and linear Bu derivs., sodium salts

Cas Number:

91078-64-7

Molecular formula:

Not applicable (UVCB substance)

IUPAC Name:

Reaction products of naphtalene, butanol, sulfonated and neautralized by caustic soda

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Wistar

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Duration of treatment / exposure:

from day 6 to day 15 p.c.

Frequency of treatment:

daily

No. of animals per sex per dose:

27 female rats

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

10 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Results (fetuses)

Details on embryotoxic / teratogenic effects:

The following parameters of maternal toxicity were impaired:
 
the body weight gain in the 60 and 360 mg/kg group dams and the feed intake in the 360 mg/kg group (60 mg/kg marginally) were reduced during the treatment period. Decreased water consumption and reduced faeces excretion were observed in some dams of the 360 mg/kg group.
 
The following parameters on intrauterine development were affected:
 
In the 360 mg/kg group increased numbers of placentas with necrotic border and slightly reduced placental weights were observed. In the 360 mg/kg group increased numbers of fetuses with skeletal variations and retardations were observed. St the dosed of 360 mg/kg b.w. increased incidences of vertebral and multiple malformations that may occur spontaneously were evident, while the overall incidence of malformations was comparable between control and 360 mg/kg group. A treatment related effect for this slightly different distribution cannot be excluded.
 
However, primary developmental toxicity was not evident, since all embryotoxic findings observed at the dose of 360 mg/kg appeared in a maternally toxic dose range.

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

60 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

skeletal malformations

other: increased numbers of placentas with necrotic border and slightly reduced placental weights.

Remarks on result:

other: Primary developmental toxicity was not evident, since all embryotoxic findings observed at the dose of 360 mg/kg appeared in a maternally toxic dose range.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

NOAEL maternal toxicity: 10 mg/kg bw
NOAEL developmental toxicity: 60 mg/kg bw

Executive summary:

The developmental toxicity potential of the substance to rats was evaluated. Wistar rats were exposed to the substance, via the oral route, daily from day 6 to day 15 p.c. The following parameters of maternal toxicity were impaired:

the body weight gain in the 60 and 360 mg/kg group dams and the feed intake in the 360 mg/kg group (60 mg/kg marginally) were reduced during the treatment period. Decreased water consumption and reduced faeces excretion were observed in some dams of the 360 mg/kg group.  

The following parameters on intrauterine development were affected:

In the 360 mg/kg group increased numbers of placentas with necrotic border and slightly reduced placental weights were observed. In the 360 mg/kg group increased numbers of fetuses with skeletal variations and retardations were observed. St the dosed of 360 mg/kg b.w. increased incidences of vertebral and multiple malformations that may occur spontaneously were evident, while the overall incidence of malformations was comparable between control and 360 mg/kg group. A treatment related effect for this slightly different distribution cannot be excluded.

However, primary developmental toxicity was not evident, since all embryotoxic findings observed at the dose of 360 mg/kg appeared in a maternally toxic dose range.

NOAEL maternal toxicity: 10 mg/kg bw day

NOAEL developmental toxicity: 60 mg/kg bw day