(R)-lactic acid

Storage stability and reactivity towards container material

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

storage stability and reactivity towards container material

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Results:

Lactic acid solutions stored at ambient temperature in polyethylene containers are stable for at least 5 years, with no change in concentration.

Transformation products:

no

Storage stability / reactivity towards container material:

other: no reactivity towards container material.

Conclusions:

L-lactic acid in polyethylene containers is stable for at least 5 years when stored at ambient conditions. There is no risk for reactivity of lactic acid towards the container material.

Executive summary:

L-lactic acid was exposed to "stressed" conditions, to investigate their effects on the stability of the acid, with regard to the formation of degradation products. When summarizing the results of the stress-testing experiments we can conclude that L-lactic acid is a stable product under most conditions tested. Only when exposed to hydrogen peroxide some oxidation occurs to acetaldehyde, pyruvic acid, acetic acid, formic acid and COX. Furthermore it is known from literature that lactic acid can decompose to acetaldehyde, formic acid and / or carbon monoxide on reaction with an excess of concentrated sulfuric acid (at room temperature) or with an excess of diluted sulfuric acid at 130 °C.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reference 2

Endpoint:

storage stability and reactivity towards container material

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Results:

Concentration of lactic acid was completely stable during the entire storage period. All other parameters were within specifications.

Transformation products:

yes

No.:

#1

No.:

#2

Conclusions:

The stability data demonstrated that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified. Given the fact that the studies were done with product of 80 % and 90 % concentration and as the results hardly show any degradation, it is justified to extrapolate the results to products with a concentration covered by that range.

Executive summary:

The stability of lactic acid when stored under controlled conditions was established in this study. Three lots of 90 % and one lot of lactic acid 80 % was tested. The samples were stored in 1L HDPE containers, resembling the commercial packaging. The samples were stored in rooms with controlled temperature and humidity. Conditions were: 25 °C, 60 % RH and 40 °C, 75 % RH. Critical on the degradation of lactic acid are color, assay and potential degradation products. Based on the result it can be concluded that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified. Given the fact that the studies were done with a product of 80 % and 90 % concentration and as the results hardly show any degradation, it is justified to extrapolate the results to products with a concentration covered by that range.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Description of key information

The stability data demonstrate that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified.