2-(hydroxymethylamino)ethanol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Genetic toxicity study in vitro was conducted to assess the ability of the Ethanol, 2-(hydroxymethylamino) to induce unscheduled DNA synthesis in primary cultures of adult rat hepatocytes. Cultures were established with cells derived from the collagenase-perfused liver of a young adult male Fischer 344 rat. The culture was exposed to Ethanol, 2-(hydroxymethylamino) at concentrations of 0.78125, 1.5625, 3.125, 6.25, 12.5, 25.0, 50.0 and 100.0 ug/ml in 2 independent experiments. Positive control was used Michler's ketone (direct acting) and 2-Acetylamino fluorine (2-AAF) (indirect acting). The cells were examined microscopically at approximately 1000x magnification under oil immersion using a Leitz Dialux 20L microscope. Unscheduled DNA Synthesis was measured by counting nuclear grains and subtracting the average number of cytoplasmic grains in 3 nuclear sized areas adjacent to each nucleus (background count). This value was referred to as the net nuclear grain count. In the first assay, there were no evidence of of unscheduled DNA synthesis up to 25 μg/ml. In the second assay, results were obtained up to 25 µg /ml with no evidence of unscheduled DNA synthesis at concentrations of 12.5 µg /ml and lower. Cell toxicity was observed at concentrations of 50 and 100 µg /ml. At the concentration of 25.5 µg/ml there was, however, a slight increase in the mean net grains per nucleus, accompanied by an increase in the percentage of cells adjudged to be in repair. The increase obtained did not meet the criteria required for a positive response, was not similarly observed in the first experiment and was not associated with a dose-related trend at lower concentrations. Unscheduled DNA Synthesis was not demonstrated by 2-[(Hydroxymethyl) amino] ethanol when tested in dimethylsulphoxide at concentrations extending into the toxic range. Therefore, the substance 2-[(Hydroxymethyl) amino] ethanol is non genotoxic to adult rat hepatocytes.

Link to relevant study records

Reference

Endpoint:

in vitro DNA damage and/or repair study

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from USEPA HPVreport

Qualifier:

according to guideline

Guideline:

other: EPA Guideline 84-2(b)

Principles of method if other than guideline:

Genetic toxicity study in vitro was conducted to assess the ability of the Ethanol, 2-(hydroxymethylamino) to induce unscheduled DNA synthesis in primary cultures of adult rat hepatocytes.

GLP compliance:

no

Type of assay:

other: unscheduled DNA Synthesis

Specific details on test material used for the study:

- Name of test material: Troysan 174, (2[(Hydroxymethyl)amino] ethanol)
- IUPAC name: 2-[hydroxy(methyl)amino]ethanol
- Molecular formula: C3H9NO2
- Molecular weight: 91.1091 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: 100 %
- Impurities (identity and concentrations): No data

Target gene:

No data

Species / strain / cell type:

hepatocytes: Rat/ Fischer 344/ adult hepatocytes -

Details on mammalian cell type (if applicable):

No data

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

not specified

Metabolic activation system:

No data

Test concentrations with justification for top dose:

0.78125, 1.5625, 3.125, 6.25, 12.5, 25.0, 50.0 and 100.0 ug/ml

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The chemical was soluble in DMSO

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

2-acetylaminofluorene

other: Michler's ketone (direct acting) at 2.0 and 8.0 ug/ml

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium
- Cell density at seeding (if applicable): No data

DURATION
- Preincubation period: No data
- Exposure duration: No data
- Expression time (cells in growth medium): No data
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data

SPINDLE INHIBITOR (cytogenetic assays): No data

STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: Duplicate

METHODS OF SLIDE PREPARATION AND STAINING TECHNIQUE USED:

NUMBER OF CELLS EVALUATED: No data

NUMBER OF METAPHASE SPREADS ANALYSED PER DOSE (if in vitro cytogenicity study in mammalian cells): No data

CRITERIA FOR MICRONUCLEUS IDENTIFICATION: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data
- Any supplementary information relevant to cytotoxicity: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Methods, such as kinetochore antibody binding, to characterize whether micronuclei contain whole or fragmented chromosomes (if applicable): No data

- OTHER: This study was conducted to assess the ability of the test compound to induce
unscheduled DNA synthesis in primary cultures of adult rat hepatocytes, as measured by silver grain counts in photographic emulsion formed by radiation from [6 3H]-thymidine taken up by the cells. The cells were examined microscopically at approximately 1000x magnification under oil immersion using a Leitz Dialux 20L microscope.

Rationale for test conditions:

No data

Evaluation criteria:

Unscheduled DNA Synthesis was measured by counting nuclear grains and subtracting the average number of cytoplasmic grains in 3 nuclear sized areas
adjacent to each nucleus (background count). This value was referred to as the net nuclear grain count. The cell cultures were scored, and the results assessed according to the criteria of Butterworth et al, in conjunction with historical data generated in-house

Statistics:

No data available

Species / strain:

hepatocytes: Rat/ Fischer 344/ adult hepatocytes -

Metabolic activation:

not specified

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

50 – 100 ug/ml

Vehicle controls validity:

valid

Remarks:

Vehicle controls were considered valid, having met the requirements as specified by the acceptance criteria

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Remarks:

Both direct and indirect acting positive controls demonstrated the sensitivity of the assays.

Additional information on results:

No data

Conclusions:

Unscheduled DNA Synthesis was not demonstrated by 2-[(Hydroxymethyl) amino] ethanol when tested in dimethylsulphoxide at concentrations extending into the toxic range. Therefore, the substance 2-[(Hydroxymethyl) amino] ethanol is non genotoxic to adult rat hepatocytes.

Executive summary:

Genetic toxicity study in vitro was conducted to assess the ability of the Ethanol, 2-(hydroxymethylamino) to induce unscheduled DNA synthesis in primary cultures of adult rat hepatocytes. Cultures were established with cells derived from the collagenase-perfused liver of a young adult male Fischer 344 rat. The culture was exposed to Ethanol, 2-(hydroxymethylamino) at concentrations of 0.78125, 1.5625, 3.125, 6.25, 12.5, 25.0, 50.0 and 100.0 ug/ml in 2 independent experiments. Positive control was used Michler's ketone (direct acting) and 2-Acetylamino fluorine (2-AAF) (indirect acting). The cells were examined microscopically at approximately 1000x magnification under oil immersion using a Leitz Dialux 20L microscope. Unscheduled DNA Synthesis was measured by counting nuclear grains and subtracting the average number of cytoplasmic grains in 3 nuclear sized areas adjacent to each nucleus (background count). This value was referred to as the net nuclear grain count. In the first assay, there were no evidence of of unscheduled DNA synthesis up to 25 μg/ml. In the second assay, results were obtained up to 25 µg /ml with no evidence of unscheduled DNA synthesis at concentrations of 12.5 µg /ml and lower. Cell toxicity was observed at concentrations of 50 and 100 µg /ml. At the concentration of 25.5 µg/ml there was, however, a slight increase in the mean net grains per nucleus, accompanied by an increase in the percentage of cells adjudged to be in repair. The increase obtained did not meet the criteria required for a positive response, was not similarly observed in the first experiment and was not associated with a dose-related trend at lower concentrations. Unscheduled DNA Synthesis was not demonstrated by 2-[(Hydroxymethyl) amino] ethanol when tested in dimethylsulphoxide at concentrations extending into the toxic range. Therefore, the substance 2-[(Hydroxymethyl) amino] ethanol is non genotoxic to adult rat hepatocytes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Genetic toxicity in vivo test was conducted to assess the potential induction of micronuclei by 2-(Hydroxymethyl) aminoethanol in bone marrow cells of mice. 15 male and 15 female mice per dose were treated with a single acute oral administration of the test substance by intragastric gavage at dosages of 0, 150, 300 and 600 mg/kg. Mitomycin C used as positive control at 12 mg/kg bodyweight and water was used as solvent control.

Bone marrow smears were obtained from five male and five female animals in the negative control and test substance groups at 24, 48 or 72 hours after dosing. Bone marrow smears were obtained from the positive control group 24 hours after dosing. One smear from each animal was examined for the presence of micronuclei in 1000 polychromatic erythrocytes. The ratio of polychromatic to normochromatic erythrocytes was assessed by examination of at least 1000 erythrocytes from each animal.

Three male and five female animals died after treatment with the highest level of 2-(Hydroxymethyl)aminoethanol in the micronucleus test. At post mortem examination, none of these animals showed signs of misdosing. No adverse clinical signs were obtained for the vehicle control or positive control treated animals over the duration of the test. A slight but statistically significant increase in the frequency of micronucleated polychromatic erythrocytes was obtained at the 24 hour sampling time for animals treated at the intermediate level (300 mg/kg) of the test substance. This increase was small and was not dose related and was not apparent at the later sampling times. There was no significant decrease in the ratio of polychromatic to normochromatic erythrocytes after treatment of the animals with 2-(Hydroxymethyl)aminoethanol. Ethanol, 2-(hydroxymethylamino) did not show any evidence of causing chromosome damage or bone marrow cell toxicity when administered orally to CD-1 mouse. Hence, the substance Ethanol, 2-(hydroxymethylamino) is not genotoxic to CD-1 mouse.

Link to relevant study records

Reference

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from USEPA HPV report

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Principles of method if other than guideline:

Genetic toxicity in vivo test was conducted to assess the potential induction of micronuclei by 2-(Hydroxymethyl) aminoethanol in bone marrow cells of mice.

GLP compliance:

no

Type of assay:

micronucleus assay

Specific details on test material used for the study:

- Name of test material: Troysan 174, (2[(Hydroxymethyl)amino] ethanol)
- IUPAC name: 2-[hydroxy(methyl)amino]ethanol
- Molecular formula: C3H9NO2
- Molecular weight: 91.1091 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: 74.3 %
- Impurities (identity and concentrations): 26.7%

Species:

mouse

Strain:

CD-1

Details on species / strain selection:

No data

Sex:

male/female

Details on test animals or test system and environmental conditions:

No data available

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: The test chemical was soluble in water
- Concentration of test material in vehicle: 0, 150, 300 and 600 mg/kg
- Amount of vehicle (if gavage or dermal): No data available
- Type and concentration of dispersant aid (if powder): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test chemical was dissolved in water to give a dose range of 0, 150, 300 or 600 mg/Kg

DIET PREPARATION
- Rate of preparation of diet (frequency): No data
- Mixing appropriate amounts with (Type of food): No data
- Storage temperature of food: No data

Duration of treatment / exposure:

Duration of test: 72 hrs
Duration of exposure: 24, 48 or 72 hours

Frequency of treatment:

Single dose

Post exposure period:

No data available

Remarks:

0, 150, 300 and 600 mg/kg

No. of animals per sex per dose:

Total: 140
0 mg/Kg bw: 15 males and 15 females
150 mg/Kg bw: 15 males and 15 females
300 mg/Kg bw: 15 males and 15 females
600 mg/Kg bw: 20 males and 20 females
Positive control: 5 males and 5 females

Control animals:

yes, concurrent vehicle

Positive control(s):

- Positive controls: Mitomycin C
- Justification for choice of positive control(s): No data
- Route of administration: oral by intragastric gavage.
- Doses / concentrations: 12 mg/kg bodyweight

Tissues and cell types examined:

bone marrow cell

Details of tissue and slide preparation:

No data available

Evaluation criteria:

A positive response is normalyy indicated by a substantial, statistically significant increase (P< 0.01) in the incidence of micronucleated polychromatic erythrocytes compared to the incidence for the concurrent vehicle control group for at least one of the dampling times; Individual and/or group mean values should exceed the laboratory historiacal control range. A negative result is indicated where individual and group mean incidences of micronucleated polychromatic erythrocytes for animals treated with the test substance are not significantly greater (P> 0.01) than incidences for the concurrent control gorup and where these values fall within the historical control range. An equvivalent response is obtained when the resukts cannot be adequately classified using the criteria for a positive or negative response.

Bone marrow cell toxicity (or depression) is normally indicated by a substantial, statistically significant decrease (P<00.1) in the ration of polychromatic to normochromatic erythrocytes. This decrease would normally be evident at both the 48 and 72 hrs sampling points, a decrease at the 24 hour point is not necessarily expected because of the relatively long transition time of erythroid cells. A very large decrease in this ration would be indicative of a cytotoxic effect.

Statistics:

Kruskal-Wallis’s test, Jonckheere’s test for trend, Wilcoxon’s sum of ranks test

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

valid

Remarks:

Mitomycin C did not cause any statistically significant decreases in the p/a ratio at the 24 hour sampling time [P>0.01 using Wilcoxon’s sum of ranks test].

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: A preliminary toxicity test had previously shown 600 mg/kg to be approximately the maximum tolerated dosage.
- Solubility: No data available
- Clinical signs of toxicity in test animals: None of these animals showed signs of misdosing at post mortem examination. No adverse clinical signs were obtained for the vehicle control or positive control treated animals over the duration of the test
- Evidence of cytotoxicity in tissue analyzed: No data available
- Rationale for exposure: No data available
- Harvest times: No data available
- High dose with and without activation: No data available
- Other:

RESULTS OF DEFINITIVE STUDY
- Types of structural aberrations for significant dose levels (for Cytogenetic or SCE assay): No data available

- Induction of micronuclei (for Micronucleus assay): A slight but statistically significant increase (P< 0.01 using Kruskal-Wallis’s test) in the frequency of micronucleated polychromatic erythrocytes was obtained at the 24 hour sampling time for animals treated at the intermediate level (300 mg/kg) of the test substance. This increase was small and was not dose related (P>0.01 using Jonckheere’s test for trend) and was not apparent at the later sampling times. Slides from this group along with those from the concurrent vehicle control were re-examined by a second slide reader and, in this instance, no significant increase in the incidence of micronucleated polychromatic erythrocytes was recorded. In all cases the group mean and individual animal incidence of micronucleated polychromatic erythrocyte values obtained were well within the laboratory historical control range. The increase recorded in the original examination is therefore thought to be the result of chance variation and is not indicative of chromosome damage. At all other sampling times and does levels, mice treated with 2-(Hydroxymethyl)aminoethanol did not show any significant increase in the frequency of micronucleated polychromatic erythrocytes.

- Ratio of PCE/NCE (for Micronucleus assay): There was no significant decrease in the ratio of polychromatic to normochromatic erythrocytes after treatment

- Appropriateness of dose levels and route: No data available

- Statistical evaluation: No data available

Table: Micronucleus test- mortality data

Dose (mg/Kg)	Mortality ratio (No. of deaths/ No. dosed)
	Male	Female	Combined
0	0/15	0/15	0/30
150	0/15	0/15	0/30
300	0/15	0/15	0/30
600	3/20	5/20	8/40
Mitomycin C (12 mg/Kg)	0/5	0/5	0/10

Conclusions:

Ethanol, 2-(hydroxymethylamino) did not show any evidence of causing chromosome damage or bone marrow cell toxicity when administered orally to CD-1 mouse. Hence, the substance Ethanol, 2-(hydroxymethylamino) is not genotoxic to CD-1 mouse.

Executive summary:

Genetic toxicity in vivo test was conducted to assess the potential induction of micronuclei by 2-(Hydroxymethyl) aminoethanol in bone marrow cells of mice. 15 male and 15 female mice per dose were treated with a single acute oral administration of the test substance by intragastric gavage at dosages of 0, 150, 300 and 600 mg/kg. Mitomycin C used as positive control at 12 mg/kg bodyweight and water was used as solvent control.

Bone marrow smears were obtained from five male and five female animals in the negative control and test substance groups at 24, 48 or 72 hours after dosing. Bone marrow smears were obtained from the positive control group 24 hours after dosing. One smear from each animal was examined for the presence of micronuclei in 1000 polychromatic erythrocytes. The ratio of polychromatic to normochromatic erythrocytes was assessed by examination of at least 1000 erythrocytes from each animal.

Three male and five female animals died after treatment with the highest level of 2-(Hydroxymethyl)aminoethanol in the micronucleus test. At post mortem examination, none of these animals showed signs of misdosing. No adverse clinical signs were obtained for the vehicle control or positive control treated animals over the duration of the test. A slight but statistically significant increase in the frequency of micronucleated polychromatic erythrocytes was obtained at the 24 hour sampling time for animals treated at the intermediate level (300 mg/kg) of the test substance. This increase was small and was not dose related and was not apparent at the later sampling times. There was no significant decrease in the ratio of polychromatic to normochromatic erythrocytes after treatment of the animals with 2-(Hydroxymethyl)aminoethanol. Ethanol, 2-(hydroxymethylamino) did not show any evidence of causing chromosome damage or bone marrow cell toxicity when administered orally to CD-1 mouse. Hence, the substance Ethanol, 2-(hydroxymethylamino) is not genotoxic to CD-1 mouse.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Gene mutation in vitro:

Various data available for the target chemical and its read across was reviewed to determine the mutagenic nature of Ethanol, 2-(hydroxymethylamino). The studies are as mentioned below:

Genetic toxicity study in vitro was conducted to assess the ability of the Ethanol, 2-(hydroxymethylamino) to induce unscheduled DNA synthesis in primary cultures of adult rat hepatocytes (USEPA, 2005). Cultures were established with cells derived from the collagenase-perfused liver of a young adult male Fischer 344 rat. The culture was exposed to Ethanol, 2 -(hydroxymethylamino) at concentrations of 0.78125, 1.5625, 3.125, 6.25, 12.5, 25.0, 50.0 and 100.0 ug/ml in 2 independent experiments. Positive control was used Michler's ketone (direct acting) and 2-Acetylamino fluorine (2-AAF) (indirect acting). The cells were examined microscopically at approximately 1000x magnification under oil immersion using a Leitz Dialux 20L microscope. Unscheduled DNA Synthesis was measured by counting nuclear grains and subtracting the average number of cytoplasmic grains in 3 nuclear sized areas adjacent to each nucleus (background count). This value was referred to as the net nuclear grain count. In the first assay, there were no evidence of of unscheduled DNA synthesis up to 25 μg/ml. In the second assay, results were obtained up to 25 µg /ml with no evidence of unscheduled DNA synthesis at concentrations of 12.5 µg /ml and lower. Cell toxicity was observed at concentrations of 50 and 100 µg /ml. At the concentration of 25.5 µg/ml there was, however, a slight increase in the mean net grains per nucleus, accompanied by an increase in the percentage of cells adjudged to be in repair. The increase obtained did not meet the criteria required for a positive response, was not similarly observed in the first experiment and was not associated with a dose-related trend at lower concentrations. Unscheduled DNA Synthesis was not demonstrated by 2-[(Hydroxymethyl) amino] ethanol when tested in dimethylsulphoxide at concentrations extending into the toxic range. Therefore, the substance 2-[(Hydroxymethyl) amino] ethanol is non genotoxic to adult rat hepatocytes.

Bacterial reverse mutation assay (USEPA, 2005) was performed to determine the muategenic nature of Troysan 174, (2[(Hydroxymethyl)amino] ethanol) using Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100 and E. coli WP2uvrA- (pKM101). The study was performed by the direct plate incorpoartion assay in the presence and absence of Aroclor 1254 liver induces S9 mix. The test chemical was dissolved in sterile ultrapure water and used at dos levels of 0, 3, 10, 33, 100, 333, and 1000 ug/plate (with) and 0, 1.7, 5, 16.7, 50, 167, and 500 ug/plate (without) in the first experiment and 0, 50, 100, 150, 200, 250, 300, 350, 400, and 450 ug/plate (with) and 0, 50, 100, 200, 300, 400, 500, and 600 ug/plate (without) in the second experiment. In the first experiment, mutagenic activity was observed in the presence of S9 mix in TA 1535 and TA 100. In TA 1535 responses were observed at 10, 33 and 333 ug/plate; in TA 100 at 333 ug per plate only whereas no mutagenic activity was observed in any strain in the absence of S9 mix. The response observed in TA 1535 was not reproduced in the second experiment. In the presence of S9 mix, TA 100 showed significant dose related increases. Mutagenic activity was also observed in TA 100 in the absence of S9 mix at 500 ug per plate only. Based on the observations made, third experiment was performed with TA 1535 in the absence, and TA 1538 in the presence and absence of S9 mix. These strains showed no mutagenic activity. In the absence of S9 mix, Strain TA98 did not meet the study criteria for acceptance in the third and the fourth experiment conducted. No mutagenic response was observed for the strain TA98 in the fifth experiment conducted. Further work was undertaken using a new batch of test material. This included retesting in S. typhimurium TA 100 and also E. coli WP2uvrA- (pKM101). A narrower range of dose levels was employed in both the presence and absence of S9 mix. Selected plates were also subjected to replicate plating to ensure that all colonies identified as being phenotypically his+ or trp+ were also genetically his+ or trp+ respectively. Clear dose-related mutagenic responses were observed in all the tests and in both of the strains employed. 2[(Hydroxymethyl)amino] ethanol did not induce gene mutation in Salmonella typhimurium strans TA1535, TA1538 and TA98 in the presence and absence of S9 metabolic activation system. It however induce gene mutation in Salmonella typhimurium strain TA100 with and without S9 mix and in E. coli WP2uvrA- (pKM101).

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, gene mutation was predicted for 2-[hydroxy(methyl)amino]ethanol. The study assumed the use of Salmonella typhimurium strainsTA 1535, TA 1537, TA 98, TA 100 and TA 102 with and without S9 metabolic activation system. 2-[hydroxy(methyl)amino]ethanol was predicted to not induce gene mutation in Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 in the presence and absence of S9 metabolic activation system and hence, according to the prediction made, the chemical is not likely to classify as a gene mutant in vitro.

Gene mutation toxicity was predicted for 2-[hydroxy(methyl)amino]ethanol using the battery approach from Danish QSAR database (2017). The study assumed the use of Salmonella typhimurium bacteria in the Ames test. The end point for gene mutation has been modeled in the Danish QSAR using the three software systems Leadscope, CASE Ultra and SciQSAR. Based on predictions from these three systems, a fourth and overall battery prediction is made. The battery prediction is made using the so called Battery algorithm. With the battery approach it is in many cases possible to reduce “noise” from the individual model estimates and thereby improve accuracy and/or broaden the applicability domain. Gene mutation toxicity study as predicted by Danish QSAR for 2-[hydroxy(methyl)amino]ethanol is negative and hence the chemical is predicted to not classify as a gene mutant in vitro.

In a study by Zeiger et al (Environmental Mutagenesis, 1987) for 50 -60% structurally similar read across chemical, Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters was performed to evaluate the mutagenic nature of N-Methyl diethanolamine (RA CAS no 105 -59 -9; IUPAC name: 2,2'-(methylimino)diethanol) using S. typhimurium tester strains TA1535, TA97, TA98 and TA100. The study was performed as per the preincubation assay and the preincubation time was 20 mins and the plates were incubated for 48 hrs. The test compound was used at a dosage level of 0, 33, 100, 333, 1000, 3333 or 10000 µg/plate in the preincubation assay of 48 hrs. Concurrent solvent and positive control chemicals were included in the study. N-Methyl diethanolamine did not induce a reproducible, dose-related increase in his⁺revertants over the corresponding solventin the S. typhimurium tester strains TA1535, TA1537, TA98 and TA100 in the presence and absence of S9 metabolic activation system and hence is negative for mutation in vitro.

In another study by Zeiger et al (Environmental mutagenesis, 1983) for structurally and functionally similar read across chemical, gene mutation toxicity study was performed to determine the mutagenic nature of the test compound 1 , 2-Propylene glycol (RA CAS no 57 -55 -6; IUPAC name: 1,2- Propanediol). The study was performed by the preincubation protocol using Salmonella typhimurium strains TA1535, TA1537, TA98, and TA100 both in the presence and absence of S9 metabolic activation system. Preincubation was carried at 37°C for 20 mins followed by exposure period of 48 hrs at dose levels of 0, 100, 333, 1000, 3333 or 10000 µg/plate. 1 , 2-Propylene glycol did not induce mutation in the Salmonella typhimurium strains TA1535, TA1537, TA98, and TA100 both in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Gene toxicity in vivo:

Data for the target chemical was reviewed to determine the mutagenic nature of in vivo 2-(Hydroxymethyl) aminoethanol. The study is as mentioned below:

Genetic toxicity in vivo test was conducted to assess the potential induction of micronuclei by 2-(Hydroxymethyl) aminoethanol in bone marrow cells of mice. 15 male and 15 female mice per dose were treated with a single acute oral administration of the test substance by intragastric gavage at dosages of 0, 150, 300 and 600 mg/kg. Mitomycin C used as positive control at 12 mg/kg bodyweight and water was used as solvent control. Bone marrow smears were obtained from five male and five female animals in the negative control and test substance groups at 24, 48 or 72 hours after dosing. Bone marrow smears were obtained from the positive control group 24 hours after dosing. One smear from each animal was examined for the presence of micronuclei in 1000 polychromatic erythrocytes. The ratio of polychromatic to normochromatic erythrocytes was assessed by examination of at least 1000 erythrocytes from each animal. Three male and five female animals died after treatment with the highest level of 2-(Hydroxymethyl)aminoethanol in the micronucleus test. At post mortem examination, none of these animals showed signs of misdosing. No adverse clinical signs were obtained for the vehicle control or positive control treated animals over the duration of the test. A slight but statistically significant increase in the frequency of micronucleated polychromatic erythrocytes was obtained at the 24 hour sampling time for animals treated at the intermediate level (300 mg/kg) of the test substance. This increase was small and was not dose related and was not apparent at the later sampling times. There was no significant decrease in the ratio of polychromatic to normochromatic erythrocytes after treatment of the animals with 2-(Hydroxymethyl)aminoethanol. Ethanol, 2-(hydroxymethylamino) did not show any evidence of causing chromosome damage or bone marrow cell toxicity when administered orally to CD-1 mouse. Hence, the substance Ethanol, 2-(hydroxymethylamino) is not genotoxic to CD-1 mouse.

Based on the data available for the target chemical and its read across, Ethanol, 2-(hydroxymethylamino) does not exhibit gene mutation in vitro and in vivo. Hence the test chemical is not likely to classify as a gene mutant in vitro and in vivo.

Justification for classification or non-classification

Based on the data available for the target chemical and its read across, Ethanol, 2-(hydroxymethylamino) does not exhibit gene mutation in vitro and in vivo. Hence the test chemical is not likely to classify as a gene mutant in vitro and in vivo.