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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1994-06-16 to 1994-09-22
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study. n-Propyl lactate used as read-across partner.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report date:
1994

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Version / remarks:
, adopted February 1987
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Reference substance name:
53651-69-7
Cas Number:
53651-69-7
IUPAC Name:
53651-69-7
Constituent 2
Reference substance name:
n-propyl lactate
IUPAC Name:
n-propyl lactate
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): n-Propyl-lactate
- Chemical name: (5)-2-hydroxypropanoic acid propylester
- Physical state: Clear, colourless liquid
- Analytical purity: 99.5 %
- Density: 1.004 kg/L
- Lot/batch No.: 3
- Storage condition of test material: ambient

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Wiga, Sulzfeld, Germany
- Age at study initiation: 5-6 weeks
- Weight at study initiation: males: 358 to 402 g, female: 210 to 241 g
- Fasting period before study: No
- Housing: In stainless steel cages with wire-screen bottom and front, 5 animals per cage; during dermal exposure the animals were housed individually
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: 65 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 52.5-92.5 (upper limit higher than the intended 70 %, because of meterological circumstances or because of wet cleaning of the animals room; the 92.5 % peak occured for ca one hour at most)
- Air changes (per hr): 10
- Photoperiod (hrs dark/hrs light): 12/12

Administration / exposure

Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
TEST SITE
- Area of exposure: 20cm²
- % coverage: 10 % of the total body surface
- Type of wrap if used: exposed area was covered by plastic foil, which was fixed by adhesive tape and the entire trunk of the rat was wrapped with an impervious material

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the skin was rinsed with lukewarm water
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 mL/kg bw
- Concentration (if solution): 99.5 %
- Constant volume or concentration used: Yes
Duration of exposure:
24 hours
Doses:
2000 mg/kg body weight
No. of animals per sex per dose:
5
Control animals:
not required
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of clinical observations: within 1 h and 4 h after the start of dosing, and subsequently at least once daily throughout an observation period
- Frequency of weighing: on day 0, 3, 7 and 14
- Necropsy of survivors performed: On day 14 of the study, all animals were killed with carbon dioxide and examined for external changes. Next the abdomen and the thorax of each animal was opened and examined for gross pathological changes.
Statistics:
N.A.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No mortality occured.
Clinical signs:
Apart from encrustation of the nose on day 1 and day 3 no clinical symptoms were observed.
Body weight:
Apart from a slight dip in the body weight of all males and four females on day 3 of the study (one animal also on day 7), all animals gained weight during the 14-day observation period.
Gross pathology:
Macroscopic examination of the animals at the end of the observation period did not reveal any treatment-related gross alterations.
Other findings:
Dermal reactions:
After treatment with the test substance, only slight encrustation was observed in two males and one female on day 1 of the study.

Any other information on results incl. tables

Table 1: Acute dermal toxicity of n-propyl lactate in rats
Animal no. Dose applied (mL)* Body weights (g) recorded on day Mortality -/+
0 3 7 14
 
Males:  
52 0.7 358 348 359 363 -
54 0.8 385 380 391 399 -
56 0.8 402 395 401 416 -
58 0.8 392 380 394 401 -
60 0.7 360 350 355 369 -
  mean 379 371 380 390  
  sem** 9 9 10 10    
 
Females:  
51 0.4 215 212 219 225 -
53 0.5 227 222 219 224 -
55 0.4 210 218 218 221 -
57 0.5 241 233 236 249 -
59 0.4 217 203 205 209 -
  mean 222 218 219 226  
  sem** 5 5 5 7    

*= dose of 2 mL per kg body weight of the undiluted test substance

**= standard error of the mean

Applicant's summary and conclusion

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
In conclusion, since no mortality occurred in an acute dermal toxicity study, the dermal LD 50 of n-propyl lactate is considered to exceed 2000 mg/kg bw, both in males and females
Executive summary:

In an acute dermal toxicity study according to OECD guideline 402, groups of Wistar rats (5/sex) were dermally applied a dose of 2000 mg/kg bw of n-propyl lactate (99.5% purity).

The animals were observed for 14 days after the single exposure. No mortalities occured after treatment with the test substance at 2000 mg/kg bw. Therefore, the dermal LD50 value is greater than 2000 mg/kg body weight, both in male and female rats. n-Propyl lactate is used as read-across partner to isobutyl-R-lactate.