Reaction mass of 2-hydroxy-4-(methylthio)butanoic acid and 2-hydroxy-4-(methylthio)butanoic acid dimer

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted before GLP and guidelines but giving enough valuable details to draw a conclusion on substance toxicity by oral route and classification.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Groups of Sprague Dawley rats (5/sex/dose) were given a single oral dose of undiluted test substance at 2000, 3000, 3500, 4000 and 5000 mg/kg bw. Animals were then observed for mortality, clinical signs and bodyweights for 14 days and were all macroscopically necropsied after death or sacrifice.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxy-4-(methylthio)butyric acid

EC Number:

209-523-0

EC Name:

2-hydroxy-4-(methylthio)butyric acid

Cas Number:

583-91-5

Molecular formula:

C5H10O3S

IUPAC Name:

2-hydroxy-4-(methylthio)butanoic acid

Details on test material:

- Name of test material (as cited in study report): LMA-88%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Weight at study initiation: see table 1

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

No data

Doses:

2000, 3000, 3500, 4000 and 5000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations: daily; weighing: at days 0, 7 and 14 after dosing
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs and body weight

Statistics:

None

Results and discussion

Preliminary study:

No data

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

3 170 mg/kg bw

Based on:

test mat.

95% CL:

>= 2 260 - <= 4 000

Mortality:

See table 1. Combined: 2/10 at 2000 mg/kg bw, 4/10 at 3000 mg/kg bw, 5/10 at 3500 mg/kg bw, 9/10 at 4000 mg/kg bw and 7/10 at 5000 mg/kg bw

Clinical signs:

other: Hypoactivity, ataxia, ptosis, salivation and lacrimation were observed in some animals after intubation. Chromodacryorrhea was seen in one animal at the highest dose.

Gross pathology:

Hemorrhages were observed in the lungs and gastrointestinal tracts of some decedents. Viscera appeared unremarkable in all survivors at terminal sacrifice.

Other findings:

No data

Any other information on results incl. tables

Table 1: summary results

Dosage (mg/kg bw)	Body weight (g)			Mortalities			Time of mortality (day:number of deaths)
	Day 0 Male/female	Day 7 Male/female	Day 14 Male/female	Male	Female	Combined
2000	206/146	278/189	324/206	0/5	0/5	2/10	Day 2:1, day 4:1
3000	201/146	258/195	304/212	2/5	2/5	4/10	Day 1:3, day 2:1
3500	207/150	275/204	316/228	2/5	3/5	5/10	Day 1:5
4000	208/146	- /174	- /205	5/5	4/5	9/10	Day 1:5, day 2:2, day 6:2
5000	206/152	253/ -	319/ -	2/5	5/5	7/10	Day 1:6, day 2:1

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The oral LD50 for LMA-88% is 3170 mg/kg in rats. As it is higher than 2000 mg/kg bw, it is not classified according to the Annex VI to the Directive 67/548/EEC and the CLP Regulation (EC) N° (1272-2008).

Executive summary:

In an acute oral toxicity study, groups of Sprague Dawley rats (5/sex/dose) were given a single oral dose of LMA-88% undiluted at 2000, 3000, 3500, 4000 and 5000 mg/kg bw. Animals were then observed for mortality, clinical signs and bodyweights for 14 days and were all macroscopically necropsied after death or sacrifice. Mortality occurred at all doses. Signs of toxicity observed were hypoactivity, ataxia, ptosis, salivation and lacrimation in some animals after intubation. Chromodacryorrhea was seen in one animal at the highest dose. Abnormalities noted at necropsy of animals that died during the study were hemorrhages in the lungs and gastrointestinal tracts. Viscera appeared unremarkable in all survivors at terminal sacrifice.

The combined oral LD50 was 3170 mg/kg with 95% confidence limits between 2260 and 4000 mg/kg bw.

The oral LD50 for LMA-88% is higher than 2000 mg/kg bw in rats therefore it is not classified according to the Annex VI to the Directive 67/548/EEC and the CLP Regulation (EC) N° (1272-2008).