Aspartic acid

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

206 mg/m³

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

other: ECETOC

Overall assessment factor (AF):

6

Modified dose descriptor starting point:

NOAEC

Value:

1 234 mg/m³

Explanation for the modification of the dose descriptor starting point:

It can be anticipated that no different toxic effects will be produced by the different routes of dosing because L-aspartic acid will be metabolised in each cell, where it enters the Krebs cycle and the urea cycle and where it is rapidly metabolised to CO2.

AF for dose response relationship:

1

Justification:

covered by route to route extrapolation

AF for differences in duration of exposure:

2

Justification:

subchronic to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

covered by route to route extrapolation

AF for other interspecies differences:

1

Justification:

covered by route to route extrapolation

AF for intraspecies differences:

3

Justification:

ECETOC TR 110 Guidance on Assessment Factors to Derive a DNEL, October 2010, page 34

AF for the quality of the whole database:

1

Justification:

most sensitive endpoint is reliable without restriction, and supported by other experimental data

AF for remaining uncertainties:

1

Justification:

not applicable

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

29 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

24

Modified dose descriptor starting point:

NOAEL

Value:

700 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

It can be anticipated that no different toxic effects will be produced by the different routes of dosing because L-aspartic acid will be metabolised in each cell, where it enters the Krebs cycle and the urea cycle and where it is rapidly metabolised to CO2.

AF for dose response relationship:

1

Justification:

covered by route to route extrapolation

AF for differences in duration of exposure:

2

Justification:

sub-chronic to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

covered by route to route extrapolation

AF for other interspecies differences:

4

Justification:

rat - human

AF for intraspecies differences:

3

Justification:

ECETOC TR 110 Guidance on Assessment Factors to Derive a DNEL, October 2010, page 34

AF for the quality of the whole database:

1

Justification:

most sensitive endpoint is reliable without restriction, and supported by other experimental data

AF for remaining uncertainties:

1

Justification:

not applicable

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

DNEL extrapolated from long term DNEL

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

61 mg/m³

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

other: ECETOC

Overall assessment factor (AF):

10

Modified dose descriptor starting point:

NOAEC

Value:

609 mg/m³

Explanation for the modification of the dose descriptor starting point:

It can be anticipated that no different toxic effects will be produced by the different routes of dosing because L-aspartic acid will be metabolised in each cell, where it enters the Krebs cycle and the urea cycle and where it is rapidly metabolised to CO2.

AF for dose response relationship:

1

Justification:

covered by route to route extrapolation

AF for differences in duration of exposure:

2

Justification:

sub-chronic to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

covered by route to route extrapolation

AF for other interspecies differences:

1

Justification:

covered by route to route extrapolation

AF for intraspecies differences:

5

Justification:

ECETOC TR 110 Guidance on Assessment Factors to Derive a DNEL, October 2010, page 34

AF for the quality of the whole database:

1

Justification:

most sensitive endpoint is reliable without restriction, and supported by other experimental data

AF for remaining uncertainties:

1

Justification:

not applicable

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

18 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

40

Modified dose descriptor starting point:

NOAEL

Value:

700 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

It can be anticipated that no different toxic effects will be produced by the different routes of dosing because L-aspartic acid will be metabolised in each cell, where it enters the Krebs cycle and the urea cycle and where it is rapidly metabolised to CO2.

AF for dose response relationship:

1

Justification:

covered by route to route extrapolation

AF for differences in duration of exposure:

2

Justification:

sub-chronic to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

covered by route to route extrapolation

AF for other interspecies differences:

4

Justification:

rat - human

AF for intraspecies differences:

5

Justification:

ECETOC TR 110 Guidance on Assessment Factors to Derive a DNEL, October 2010, page 34

AF for the quality of the whole database:

1

Justification:

most sensitive endpoint is reliable without restriction, and supported by other experimental data

AF for remaining uncertainties:

1

Justification:

not applicable

Acute/short term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

18 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

40

DNEL extrapolated from long term DNEL

Explanation for the modification of the dose descriptor starting point:

It can be anticipated that no different toxic effects will be produced by the different routes of dosing because L-aspartic acid will be metabolised in each cell, where it enters the Krebs cycle and the urea cycle and where it is rapidly metabolised to CO2.

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - General Population

L-aspartic acid is a naturally occurring substance. It is a basic component of proteins, together with L-glutamic acid they account for approximately 20-25 % of the total amino acid composition of dietary protein, including those found in human breast milk. L-aspartic acid enters the citric acid cycle and the urea cycle and is metabolised there. 

Protein digestion results mainly in free amino acids and small peptides in the intestinal lumen which were absorbed leading finally to blood plasma levels of L-aspartic acid between 1-25 µmol/L. Cells contain a considerable quantity of free L-aspartate. Considerable quantities of these amino acids are also found in human brain and liver.

It is obvious that human cells handle large quantities of L-aspartate / L-aspartic acid and that this amino acid is an essential component of normal cellular function.

It is therefore highly improbable that L-aspartic acid possesses any relevant toxicity.