L-proline

Endpoint summary

Description of key information

An acute oral LD50 value of > 5110mg/kg bw  from a reliable study was derived. No mortality occured during the observation period of 14 days. No signs of toxicity were observed either at the male nor the female animals.  
The acute dermal study and the acute inhalation study were waived based on the very low systemic toxicity as well as on the physico-chemical and toxikokinetic properties.

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

Study period:

1983-03-10 to 1983-04-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Qualifier:

no guideline available

Principles of method if other than guideline:

Intercomparison Study on the Determination of Single Administration Toxicity in Rats, Commission of the European Communities, Health and Safety
Directorate, J. Assoc. Off. Anal. Chem. 62, 864-873, 1979

GLP compliance:

no

Remarks:

Study performed prior to implementation of GLP

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen
- Age at study initiation: males 48 - 51 days, females 55 - 62 days
- Weight at study initiation: males 129 - 135 g, females 129 - 138 g
- Fasting period before study: 16 hours
- Housing: Makrolon cages type II
- Diet (e.g. ad libitum): standardised test animal diet ALTROMIN
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days acclimatisation period before study begin

ENVIRONMENTAL CONDITIONS
According to method

IN-LIFE DATES: From: To: no data available

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 238 mg/ml
- Amount of vehicle (if gavage): 21.5 ml/kg
- Justification for choice of vehicle: solubilty, inherent vehicle
- Lot/batch no. (if required): not applicable
- Purity: ca. 100 %

MAXIMUM DOSE VOLUME APPLIED: 21.5 ml/kg

Doses:

5110 mg/kg

No. of animals per sex per dose:

5

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: no data available
- Necropsy of survivors performed: no data vailable

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 110 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occured during the observation period of 14 days.

Clinical signs:

other: No signs of toxicity were observed either at the male nor the female animals.

Gross pathology:

No data available

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

The LD50 value of L-proline via the oral route represented by male and female rats was > 5110 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 110 mg/kg bw

Quality of whole database:

The study was performed prior to the implementtaion of GLP but isomparable to guideline study with acceptable restrictions.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

L-proline did not show any mortality in an oral acute toxicity study. The LD50 value of L-proline via the oral route represented by male and female rats was > 5110 mg/kg body weight.

No toxic effects were observed in a 13 week sub-chronic oral toxicity study in which L-proline was adminstered in an oral daily dose up to 5 %. These results show that the toxicity of L-proline via the oral route is extremely low.

Inhalation is not a relevant route based upon the vapour pressure and particle size (granulometry) of L-proline.

There is sufficient weight of evidence for the absence of acute toxicity via the inhalation route.

No data on acute dermal toxicity for L-proline is available. Due to its very low systemic toxicity and the fact that L-proline (with high water solubility and a log P value well below 0) may be too hydrophilic to cross the lipid rich environment of the stratum corneum it is highly improbable that an acute dermal toxicity study would result in any toxicity.

Justification for selection of acute toxicity – oral endpoint
Key study

Justification for classification or non-classification

Based on the data available no classification for acute toxicity (oral toxicity, dermal toxicity, inhalation toxicity) is required.