Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 225-582-5 | CAS number: 4940-11-8
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
Gene mutation (Bacterial Reverse Mutation Assay/Ames test): the substance Ethyl Maltol was mutagenic in the strain S. typhimurium TA 100 in the presence and absence of S9 metabolic activation. (No guideline).
Chromosome aberration (in vitro cytogenicity/micronucleus study): This study is waived as an in vivo mammalian erythrocyte micronucleus test is available.
Gene mutation (mammalian cell gene mutation assay) (Read-across to Kojic acid (CAS No. 501-30-4)): Kojic acid did not induce mutation at the hprt locus of L5178Y mouse lymphoma cells in the absence or presence of Aroclor 1254-induced rat liver S9 (OECD 476/GLP).
Link to relevant study records
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1979
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Remarks:
- Validity of study confirmed by EFSA (FGE.213), Only tested strains TA98 and TA100, Quercetin and sterigmatocystin were used as positive controls. Max dose tested 2 mg/plate.
- Qualifier:
- according to guideline
- Guideline:
- other: Ames, B.N., J. McCann and E. Yamasaki, Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test, Mutation Res., 31 (1975) 347-364.
- Deviations:
- yes
- Remarks:
- Only tested strains TA98 and TA100, Quercetin and sterigmatocystin were used as positive controls. Max dose tested 2 mg/plate.
- GLP compliance:
- no
- Remarks:
- pre-GLP
- Type of assay:
- bacterial reverse mutation assay
- Target gene:
- Histidine (hisG46, hisD3052)
- Species / strain / cell type:
- S. typhimurium TA 98
- Details on mammalian cell type (if applicable):
- CELLS USED
- Source of cells: Provided by B.N. Ames
- Suitability of cells: commonly used strain to detect frameshift reverse mutation - Additional strain / cell type characteristics:
- other: R factor plasmid, pKM101, deep rough coat mutation and uvrB deletion
- Species / strain / cell type:
- S. typhimurium TA 100
- Details on mammalian cell type (if applicable):
- CELLS USED
- Source of cells: Provided by B.N. Ames
- Suitability of cells: commonly used strain to detect base-pair substitution reverse mutation - Additional strain / cell type characteristics:
- other: R factor plasmid, pKM101, deep rough coat mutation and uvrB deletion
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9
- Test concentrations with justification for top dose:
- 0.5, 1 and 2 mg/plate
- Vehicle / solvent:
- Filter sterilised water
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- not specified
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- benzo(a)pyrene
- other: Quercetin, Sterigmatocystin
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in medium; in agar (plate incorporation)
DURATION
- Exposure duration: 48h
DETERMINATION OF CYTOTOXICITY
- Method: not specified - Rationale for test conditions:
- As described by Ames et al. (1975)
- Evaluation criteria:
- Not specified
- Statistics:
- The mean number of revertant colonies is calculated from triplicate runs, and the number of spontaneous revertants is subtracted from each value.
Further statistics were not specified. - Key result
- Species / strain:
- S. typhimurium TA 98
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity
- Remarks:
- max dose tested 2 mg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- positive
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity
- Remarks:
- max dose tested 2 mg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: the publication did not mention precipitation, also not at the highest dose tested 2 mg/plate
ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Measurement of cytotoxicity used: Cytotoxicity was not observed for ethyl maltol up to the highest concentration tested (2 mg/plate). - Conclusions:
- Under the conditions of this test, a dose related mutagenic effect was observed for Ethyl Maltol against tester strain TA100 but not in strain TA98.
- Executive summary:
In a reverse gene mutation assay in bacteria (Bjeldanes and Chew, 1979), strains of S. typhimurium TA 98 and TA 100 were exposed to Ethyl Maltol at concentrations of 0.5, 1 and 2 mg/plate (plate incorporation) in the presence and absence of mammalian metabolic activation (S9). Quercetin, sterigmatocystin and benzo[a]pyrene were used as positive controls. The study was judged to be valid by the EFSA (FGE.213) and rated Klimisch 2.
The substance induced a dose-related increase in the number of revertant colonies in S. typhimurium TA100, both in the absence and presence of S9 metabolic activation. No mutagenicity was observed in strain TA98. Under the conditions of this study, the test substance is considered mutagenic.
EFSA Journal 2015;13(9):4244
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 19-11-2001 to 28-03-2002
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Reason / purpose for cross-reference:
- read-across: supporting information
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
- Version / remarks:
- 21 July 1997
- GLP compliance:
- yes
- Type of assay:
- other: Mammalian cell gene mutation assay
- Target gene:
- HPRT
- Species / strain / cell type:
- mouse lymphoma L5178Y cells
- Details on mammalian cell type (if applicable):
- CELLS USED
- Source of cells: Dr. Donald Clive, Burroughs Wellcome Co.
- Suitability of cells: the mammalian mouse lymphoma L5178Y cell line has been sufficiently well validated for use in in vitro mutation assays.
- Methods for maintenance in cell culture if applicable:
L5178Y TK mouse lymphoma cells were stored as frozen stocks in liquid nitrogen, the original cultures were obtained from Dr Donald Clive, Burroughs Wellcome Co. Each batch of frozen cells was purged of TK", mutants, checked for spontaneous mutant frequency and that it was mycoplasma free. For each experiment, at least one vial was thawed rapidly, the cells diluted in RPMI 10 and incubated in a humidified atmosphere of 5% v/v CO2 in air. When the cells were growing well, subcultures were established in an appropriate number of flasks.
MEDIA USED
- Type and identity of media: RPMI 1640 medium with Horse Serum, Gentamycin, Amphotericin B and Pluronic.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically 'cleansed' against high spontaneous background: yes - Additional strain / cell type characteristics:
- not specified
- Metabolic activation:
- with and without
- Metabolic activation system:
- Aroclor 1254 induced rat liver post-mitochondrial fraction (S9)
- Test concentrations with justification for top dose:
- Cytotoxicity range-finding experiment: six doses, ranging from 43.75, 87,5, 175, 350, 700 and 1421 μg/mL (equivalent to 10mM at the highest concentration tested, in accordance with OECDTG476)
Main Experiments: five doses, ranging from 300, 600, 900, 1200 and 1421 μg/mL - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: purified water
- Justification for choice of solvent/vehicle: the test item was soluble in purified water up to at least 27 mg/mL - Untreated negative controls:
- no
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- 4-nitroquinoline-N-oxide
- benzo(a)pyrene
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in medium; in suspension
- Cell density at seeding (if applicable): cytotoxicity range finding: 8 cells/mL, main experiment 2 x 10^5 cells/mL
DURATION
- Exposure duration: 3 hours
- Expression time (cells in growth medium): 7 days
- Selection time (if incubation with a selection agent): 13 to 14 days
SELECTION AGENT (mutation assays): 6-thioguanine
NUMBER OF REPLICATIONS: 2 independent experiments with 2 replicates each
DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency - Rationale for test conditions:
- The test is performed in line with OECDTG476
- Evaluation criteria:
- The test substance was considered to be mutagenic if:
1. the assay was valid
2. the mutant frequency at one or more doses was significantly greater than that of the negative control
3. there was a significant dose-relationship as indicated by the linear trend analysis
4. the effects described above were reproducible. - Statistics:
- Determination of survival or viability
Calculation of the probable number of clones/well (P) on a microtitre plate in which there are empty wells (EW) (total well number TW):
P = -ln(EW/TW)
Plating Efficiency (PE)
PE = P/number of cells plated per well
The percentage relative survival (%RS)
% RS = [PE (test) PE (control)] X 100
Adjusted percentage relative survival values for each dose of test article:
Adjusted %RS = %RS x Post-treatment cell concentration for dose / Post-treatment cell concentration for solvent control
Determination of mutant frequency (MF)
MF = [PE (mutant)/PE (viable)] x 10^6
Assessment of statistical significance of mutant frequencies was carried out according to the UKEMS guidelines. Thus the control log mutant frequency (LMF) was compared with the LMF from each treatment dose, and secondly the data were checked for a linear trend in mutant frequency with treatment dose. These tests require the calculation of the heterogeneity factor to obtain a modified estimate of variance. - Key result
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- RANGE-FINDING/SCREENING STUDIES: No cytotoxicity was observed at any dose level tested in the absence or presence of S9. The highest dose tested (1421 µ/mL) yielded 97% relative survival in the absence of S9 and 115% relative survival in the presence of S9.
HISTORICAL CONTROL DATA
Treatment MF MFi-MFc Ratio C/H
Negative control 6.06 1.542
0,1 NQO 31.64 25.58 0.698
0,15 NQO 44.39 38.33 0.759
MF = Mutant Frequency
MFi = Mutant Frequency Induced
MFc = Mutant Frequency Control
Ratio C/H = Current/Historical - Conclusions:
- Kojic acid did not induce any toxicologically significant increases in the mutant frequency at the HPRT locus in the L5178Y cells and was therefore not considered to be mutagenic under the conditions of the test.
- Executive summary:
In a mammalian cell gene mutation assay (Hprt; 413/45-D6173), mouse lymphoma L5178Y cells cultured in vitro were exposed to Kojic Acid in water at concentrations of 300, 600, 900, 1200 and 1421 µg/mL in the presence and absence of mammalian metabolic activation (Aroclor-induced rat liver S9) for 3 hours.
There was no cytotoxicity or precipitation but Kojic Acid was tested up to the limit concentration. The positive controls induced the appropriate response.
A small statistically significant increase in mutant frequency was observed following treatment with Kojic acid at the lowest dose level (300 μg/mL) tested in the presence of S9, in Experiment 2. However, there was no evidence of a dose-related response in this experiment (indicated by a non-significant linear trend) and no other statistically significant increases in mutant frequency were observed at any dose level tested in the absence or presence of S9 in Experiments 1 and 2. This observation was therefore considered to be a chance event of no biological significance. It may be noted that the unusually high heterogeneity values were observed for mutation (at 600 μg/mL in the presence of S9 in Experiment 1 and at 900 μg/mL in the presence of S9 in Experiment 2) and for viability (at 900 μg/mL in the absence of S9 in Experiment 2). The levels of heterogeneity observed in these treatments were sporadic and were not believed to have prejudiced the validity of the study in any way, therefore they were included in the analyses. Therefore, under the conditions in this study, Kojic Acid is not mutagenic in this test system.
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Result derived from read across is sufficiently reliable because all Annex XI criteria are met.
- Justification for type of information:
- The read across justification is presented in the Genotoxicity Endpoint summary. The accompanying files are also attached there.
- Reason / purpose for cross-reference:
- read-across source
- Key result
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Conclusions:
- Based on the results of the study for read-across substance Kojic acid, Ethyl Maltol is not considered to be mutagenic in mammalian cells.
- Endpoint:
- in vitro cytogenicity / micronucleus study
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- an in vitro cytogenicity study in mammalian cells or in vitro micronucleus study does not need to be conducted because adequate data from an in vivo cytogenicity test are available
Referenceopen allclose all
A small statistically significant increase in mutant frequency was observed following treatment with Kojic acid at the lowest dose level (300 μg/mL) tested in the presence of S9, in Experiment 2. However, there was no evidence of a dose-related response in this experiment (indicated by a non-significant linear trend) and no other statistically significant increases in mutant frequency were observed at any dose level tested in the absence or presence of S9 in Experiments 1 and 2. This observation was therefore considered to be a chance event of no biological significance. It may be noted that the unusually high heterogeneity values were observed for mutation (at 600 μg/mL in the presence of S9 in Experiment 1 and at 900 μg/mL in the presence of S9 in Experiment 2) and for viability (at 900 μg/mL in the absence of S9 in Experiment 2). The levels of heterogeneity observed in these treatments were sporadic and were not believed to have prejudiced the validity of the study in any way, therefore they were included in the analyses.
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Genetic toxicity in vivo
Description of key information
Cytogenicity (mammalian erythrocyte micronucleus test): Ethyl Maltol was found to be negative in an in vivo micronucleus assay (Equivalent or similar to OECD 474).
Link to relevant study records
- Endpoint:
- in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1982
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Remarks:
- Intraperitoneal administration of test substance (not justified), only 4 animals per dose, no toxicity measurements in the bone marrow included.
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
- Deviations:
- yes
- Remarks:
- Intraperitoneal administration of test substance, sampling at different time intervals after single exposure (24, 48 and 72 hours)
- Qualifier:
- according to guideline
- Guideline:
- other: M. Salamone et al. Towards an improved micronucleus test Studies on 3 model agents. In Mutation Research/Environmental Mutagenesis and Related Subjects, Volume 74, Issue 5, 1980, Pages 347-356, ISSN 0165-1161.
- GLP compliance:
- no
- Type of assay:
- other: Micronucleus test
- Species:
- mouse
- Strain:
- NMRI
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Ivanovas GmbH, Kisslegg
- Age at study initiation: 10-14 weeks
- Diet: Altromin standard chow ad libitum
- Water: ad libitum - Route of administration:
- intraperitoneal
- Vehicle:
- - Vehicle(s)/solvent(s) used: olive oil
- Frequency of treatment:
- Two doses (at 0h and 24h) or single dose (at 0h)
- Post exposure period:
Groups exposed twice: 30h
Groups exposed once: 24h, 48h, 72h- Dose / conc.:
- 980 mg/kg bw (total dose)
- Remarks:
- Administered as single dose (0h) or dosed twice (0h and 24h)
- Dose / conc.:
- 700 mg/kg bw (total dose)
- Remarks:
- Administered twice (0h and 24h)
- Dose / conc.:
- 420 mg/kg bw (total dose)
- Remarks:
- Administered twice (0h and 24h)
- No. of animals per sex per dose:
- 4
- Control animals:
- yes, concurrent vehicle
- Positive control(s):
- none
- Tissues and cell types examined:
- polychromatic erythrocytes in the bone marrow
- Details of tissue and slide preparation:
DETAILS OF SLIDE PREPARATION:
Bone-marrow smears were prepared 24h, 30h, 48h or 72h after treatment. The smears were stained according to the method of Schmid (1976).
METHOD OF ANALYSIS:
Slides were scored as previously described (Wild, King & Eckhardt, 1980).- Evaluation criteria:
- no data
- Statistics:
- Statistical significance was determined according to the methods of Kastenbaum & Bowman (1970)
- Key result
- Sex:
- female
- Genotoxicity:
- negative
- Toxicity:
- not examined
- Vehicle controls validity:
- valid
- Negative controls validity:
- not applicable
- Positive controls validity:
- not applicable
- Additional information on results:
RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no effect
- Ratio of PCE/NCE (for Micronucleus assay) was not examined- Conclusions:
- Under the conditions of this study, Ethyl Maltol did not induce any increase in micronucleated erythrocytes after peritoneal injection in mice.
- Executive summary:
In an NMRI mouse mammalian erythrocyte micronucleus test (Wild et al., 1983), groups of 4 female mice were treated intraperitoneally with Ethyl Maltol in olive oil at doses of 980 mg/kg bw (one dose) or 480, 700, 980 mg/kg bw (two doses 0hrs, 24hrs). Animals were sacrificed 24, 48 or 72 hrs after single treatment, or 30 hours after the second treatment.
Slides were scored for the mean number of micronucleated PE/1000PE (Polychromatic Erythrocytes). After two exposures to 980, 700, 420 or 0 mg/kg bw, the mean numbers of micronucleated PE/100PE were 3.0, 3.2, 2.3 and 1.3 respectively. After a single exposure to 980 mg/kg bw (24, 48, 72 hrs), the number of micronucleated PE/1000PEs were 1.3, 3.5 and 1.8 respectively, with a control value of 2.7. No statistically significant differences were observed. The results of these tests therefore indicate no mutagenic potential of the test substance.
Reference
Results of micronucleus tests on mouse bone marrow after exposure to Ethyl Maltol
Dose (mg/kg) | Surviving/treated mice | Mean no. of micronucleated PE/1000 PE |
0 | 4/4 | 1.3 |
2*980 | 4/4 | 3.0 |
2*700 | 4/4 | 3.2 |
2*420 | 4/4 | 2.3 |
0 | 4/4 | 2.7 |
1* 980 (24 hr) | 4/4 | 1.3 |
1* 980 (48 hr) | 4/4 | 3.5 |
1* 980 (72 hr) | 4/4 | 1.8 |
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Additional information
In vitro studies
There is one in vitro bacterial reverse mutation/Ames test available. There are no in vitro cytogenicity/micronucleus studies available. There is one gene mutation (mammalian cell gene mutation assay) available (read-across to Kojic Acid (CAS No. 501-30-4)).
Gene mutation (Bacterial Reverse Mutation Assay/Ames test):
In a reverse gene mutation assay in bacteria (no guideline), strains of S. typhimurium TA 98 and TA 100 were exposed to Ethyl Maltol at concentrations of 0.5, 1 and 2 mg/plate (plate incorporation) in the presence and absence of mammalian metabolic activation (S9). Quercetin, sterigmatocystin and benzo[a]pyrene were used as positive controls. The study was judged to be valid by the EFSA (FGE.213) and rated Klimisch 2.
The substance induced a dose-related increase in the number of revertant colonies in S. typhimurium TA100, both in the absence and presence of S9 metabolic activation. No mutagenicity was observed in strain TA98. Under the conditions of this study, the test substance is considered mutagenic.
EFSA Journal 2015;13(9):4244
Chromosome aberration (in vitro cytogenicity/micronucleus study):
This study is waived as an in vivo mammalian erythrocyte micronucleus test is available.
Gene mutation (mammalian cell gene mutation assay):
In a mammalian cell gene mutation assay (Hprt; OECD 476/GLP), mouse lymphoma L5178Y cells cultured in vitro were exposed to Kojic Acid in water at concentrations of 300, 600, 900, 1200 and 1421 µg/mL in the presence and absence of mammalian metabolic activation (Aroclor-induced rat liver S9) for 3 hours.
There was no cytotoxicity or precipitation but Kojic Acid was tested up to the limit concentration. The positive controls induced the appropriate response.
A small statistically significant increase in mutant frequency was observed following treatment with Kojic acid at the lowest dose level (300 μg/mL) tested in the presence of S9, in Experiment 2. However, there was no evidence of a dose-related response in this experiment (indicated by a non-significant linear trend) and no other statistically significant increases in mutant frequency were observed at any dose level tested in the absence or presence of S9 in Experiments 1 and 2. This observation was therefore considered to be a chance event of no biological significance. It may be noted that the unusually high heterogeneity values were observed for mutation (at 600 μg/mL in the presence of S9 in Experiment 1 and at 900 μg/mL in the presence of S9 in Experiment 2) and for viability (at 900 μg/mL in the absence of S9 in Experiment 2). The levels of heterogeneity observed in these treatments were sporadic and were not believed to have prejudiced the validity of the study in any way, therefore they were included in the analyses. Therefore, under the conditions in this study, Kojic Acid is not mutagenic in this test system.
Read-across justification:
Introduction and hypothesis for the read across
Ethyl Maltol is a 4-pyranone with an ethyl and hydroxyl group attached at the 2 and 3 position, respectively. For this substance an Ames test, and in vivo mammalian erythrocyte micronucleus test are available but no data regarding in vitro genemutations in mammalian cells is available.In accordance with Article 13 of REACH, lacking information should be generated whenever possible by means other than vertebrate animal tests, i.e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For assessing the in vitro genemutations in mammalian cells for Ethyl Maltol the analogue approach is selected because for one closely related analogue, Kojic acid, such in vitro mutagenicity data is available.
Hypothesis:Ethyl Maltolis not expected to be mutagenic to mammalian cells based on analogue information from Kojic acid.
Available information: For Ethyl Maltol a positive Ames test is available (similar to OECD TG 471, Kl2) and a negative in vivo micronucleus test is available (similar to OECD TG 474, Kl2). For Ethyl Maltol also a carcinogenicity study is available (similar to OECD TG 453, Kl2), showing negative results. No data regarding in vitro genemutations in mammalian cells is available. To fill this genetic toxicity endpoint information from Kojic acid is used for read across. Kojic acid is negative for in vitro genemutations in mammalian cells (OECD TG 476, Kl 1) showing negative results. Also other genotoxicity information is available and reviewed by SCCP. Despite some positive effects in in vitro studies the substance is considered negative for in vitro and in vivo genotoxicity (SCCP, 1182/08).
Target and Source chemical(s):
Chemical structure of the target chemical (Ethyl Maltol) is shown in Data matrix, including physico-chemical properties and toxicological information, thought relevant for using the read across.
Purity / Impurities:
The purity and impurities of Ethyl Maltol do not indicate in vitro gene mutation potential other than indicated by the parent substance. The impurities are all below 1 %.
Analogue approach justification
According to REACH Annex XI an analogue approach and structural alert information can be used to replace testing when information from different sources provides sufficient evidence to conclude that this substance has or does not have a particular dangerous property. The result derived should be applicable for C&L and/or risk assessment and be presented with adequate and reliable documentation.
Analogue selection:Analogues identified in the OECD QSAR toolbox by using structural similarity with Tanimoto 80% did not reveal any substances. Therefore analogues were identified in the OECD QSAR toolbox by using structural similarity with Tanimoto 60%, which showed 10 substances. Kojic acid and Maltol were both considered as possible RA candidates. As mutagenicity testing is ongoing for Maltol and a final conclusion cannot be made, Kojic acid is used as source substance.
Structural similarities and differences:Thetarget chemical, Ethyl Maltol and source chemical, Kojic acid both have a3-hydroxy-4-pyranone backbone and functional group. There are two differences between these two substances: Ethyl Maltol has its alcohol group attached to the ring mirrored compared to Kojic acid. The second difference is that Ethyl Maltol has an ethyl group at the ring where Kojic acid has a hydroxymethyl group.
Toxicokinetics:Absorption of Ethyl Maltol and Kojic acid will be alike based on the similarity in being solids, molecular weight are 140 and 142, the water solubilities are9345 and 43850 mg/L, and calculated log Kow values of 0.29 and -1.25, respectively. The log Kow of Ethyl Maltol is somewhat higher due to the extra methyl group instead of an OH group at this spot.
Metabolism: Theoretically the ethyl group in Ethyl Maltol may turn intoalcohol, aldehyde and finally acid. At this spot in the chemical structure Kojic acid already has an alcohol at its methyl group and may turn into an acid. Experimentally Ethyl Maltol was recovered in the urine of dogs as being glucuronic conjugates or as ethereal sulphates (Rennhard et al., 1971). In a report by Sansho Seiyaku Co (2001) to the ADME of Kojic acid in the rat, Kojic acid was detected in the urine and liver. Metabolites in all organs or tissues detected were glucuronate (6.4 – 39.6% of total radioactivity) and mainly sulphate (35.6 –93.7% of total radioactivity) conjugates of Kojic acid. This is comparable to the experimental findings in the study by Rennhard et al. (1971).
Toxicodynamics, reactivity: Ethyl Maltol and Kojic acid have electrophilic features in the form of alpha and beta unsaturated carbonyls, which can promote to Michael addition, and may cause genotoxicity by combination with nucleophilic groups in nucleic acids. Both Ethyl Maltol and Kojic acid have an OH group (electron withdrawing) attached to the ring. The differences in reactivity between these two substance (ethyl and hydroxymethyl group) can be shown by pKa predictions of both substances. Ethyl Maltol has a higher pKa (11.26) and thus a slightly lower reactivity compared to Kojic acid which has a pKa 7.6.Based on the pKa Ethyl Maltol is expected to be slightly less reactive than Kojic acid. This reactivity of both Ethyl Maltol and Kojic acid may have led to the positive results in the Ames test.
Remaining uncertainties:There are no remaining uncertainties because Ethyl Maltol andKojic acidare structurally very close analogues and also their metabolites. Both are positive in the Ames test. Ethyl Maltol is considered slightly less reactive and therefore read across from Kojic acid is conservative.
Data matrix
The relevant information on physico-chemical properties and toxicological characteristics are presented in the data matrix in Table 1 to further support the read across between Ethyl Maltol and Kojic acid.
Conclusionsfor in vitro mammalian gene mutation
For Ethyl Maltol a positive Ames test is available as well as a negative in vivo micronucleus test similar to OECD TG 471 and 474, respectively.To cover the in vitro genemutations in mammalian cells, information from Kojic acid is used to fill this data gaps. Kojic acid is negative in this test and therefore Ethyl Maltol is also expected to be negative in this test.
Final conclusion on hazard and application in the risk assessment:
Ethyl Maltol is negative in the in vitro gene mutations in mammalian cells.
Common names |
Ethyl Maltol |
Kojic acid |
|
Target |
Source |
Chemical name: IUPAC |
2-Ethyl-3-hydroxy-4H-pyran-4-one |
5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one |
Chemical structure |
||
CAS no. |
4940-11-8 |
501-30-4 |
Einecs no |
225-582-5 |
207-922-4 |
Reach registration |
REACH 2018 registration |
Not REACH registered |
Molecular weight |
140 |
142 |
Physical state |
Solid |
Solid |
Physico-chemical data |
|
|
Vapour pressure (Pa) |
0.2 (IFF measured) |
0.000102 (EpiSuite) |
Water solubility (mg/l) |
9345 (IFF measured) |
43850 (SCCP) |
Log Kow |
2.9 (IFF measured) |
-0.64 (measured from EpiSuite) |
Log Kow predicted |
0.29 |
-1.25 |
pKa |
11.26 (SPARC) |
7.9 and 8.03 (SCCP) |
Human toxicology |
|
|
Acute oral Toxicity mg/kg bw |
1220 (OECD TG 401) |
1000-4000 (OECD TG 401, SCCP) |
Ames |
Positive (OECD TG 471) |
Positive (OECD TG 471) |
In vitro mutagenicity in genemutations in mammalian cells |
Read Across |
Negative (OECD TG 476) |
In vivo mammalian cytogenicity |
Negative (Similar to OECD 474) |
Negative (OECD TG 474) |
Genotoxic carcinogenicity |
Negative (Similar to OECD TG 453) |
Negative (SCCP) |
References
Rennhard H.H., 1971, Metabolism of ethyl Maltol and Maltol in the dog, J. Agric. Food Chem., 19 (1), pp 152–154
Sansho Seiyaku, Absorption, Distribution, Metabolism, and Excretion (ADME) of Kojic Acid in the Rat - Revision of 2001 Institute of Whole Body metabolism Sansho Seiyaku Co., Ltd. unpublished report
SCCP/1182/08. Opinion on Kojic Acid, adopted by the SCCP during the 17th plenary meeting of 30 September 2008:https://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_148.pdf.
In vivo studies
There is one mammalian erythrocyte micronucleus test available.
Cytogenicity (mammalian erythrocyte micronucleus test):
In an NMRI mouse mammalian erythrocyte micronucleus test ((Equivalent or similar to OECD 474), groups of 4 female mice were treated intraperitoneally with Ethyl Maltol in olive oil at doses of 980 mg/kg bw (one dose) or 480, 700, 980 mg/kg bw (two doses 0hrs, 24hrs). Animals were sacrificed 24, 48 or 72 hrs after single treatment, or 30 hours after the second treatment.
Slides were scored for the mean number of micronucleated PE/1000PE (Polychromatic Erythrocytes). After two exposures to 980, 700, 420 or 0 mg/kg bw, the mean numbers of micronucleated PE/100PE were 3.0, 3.2, 2.3 and 1.3 respectively. After a single exposure to 980 mg/kg bw (24, 48, 72 hrs), the number of micronucleated PE/1000PEs were 1.3, 3.5 and 1.8 respectively, with a control value of 2.7. No statistically significant differences were observed. The results of these tests therefore indicate no mutagenic potential of the test substance.
Overall conclusion:
There is a positive in vitro bacterial reverse mutation assay/Ames test. According to the EFSA expert panel in 2015, the result from the combined chronic toxicity/carcinogenicity OECD 453 study conducted with Ethyl Maltol (Refer to 7.5.1) overrules the mutagenicity observed in bacteria.
There is a negative mammalian cell gene mutation assay (read-across to Kojic Acid (CAS No. 501-30-4)). There is a negative in vivo mammalian erythrocyte micronucleus test. Therefore the overall conclusion on the genotoxic properties is negative.
EFSA Journal 2015;13(9):4244
Justification for classification or non-classification
Based on the available information in the dossier, the substance Ethyl Maltol (CAS No. 4940-11-8) does not need to be classified for germ cell mutagenicity when the criteria outlined in Annex I of 1272/2008/EC are applied.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.