1-aminopropan-2-ol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

MIPA did not cause gene mutations in S. typhimurium/E. coli (Ames test) or in Chinese hamster ovary cells (CHO/HGPRT) according or similar to OECD 471 or OECD 476, respectively. No chromosomal aberrations were induced in rat lymphocytes according to OECD 473. All studies were performed in the absence and presence of metabolic activation. Thus, MIPA is not considered to be genotoxic.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

- initial OECD TG 471 + 472, adopted 26 May 1983.
- OECD 471, adopted: 21 July 1997, corrected: 26 June 2020.

Deviations:

no

Principles of method if other than guideline:

based on Ames et al. (1975) with modifications originally described by Yahagi et al. (1975) and Maron and Ames (1983):
- Ames, B.N., McCann, J. and Yamasaki, E. (1975). Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test. Mutation Research 2:347-364.
- Maron, D.M., and Ames B. (1983). Revised Methods for the Salmonella Mutagenicity Test. Mutation Research 113: 173-2 15.
- Yahagi, T., Degawa, M., Seino Y., Matsushima, T., Nagao, M., Sugimura, T., and Hashimoto, Y. (1975). Mutagenicity of carcinogenic azo dyes and their derivatives. Cancer Letters 1:91-96.

This methodology (preincubation modification) has been shown to detect mutagenicity with certain classes of chemicals, such as nitrosamines or volatile test articles, which may not be detected in the standard plate incorporation method.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Chemical Name: Monoisopropanolamine (MIPA)

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: The Dow Chemical Co., Midland, MI,
lot MM930105
- Purity, including information on contaminants, isomers, etc.: 99.63%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability and homogeneity of the test material in the vehicle/solvent under test conditions (e.g. in the exposure medium) and during storage: Actual concentrations of the stock test articles dosing solutions ranged from 87% to 116% of target. Clear, colorless solution at 100 mg/ml in sterile deionized water.

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Remarks:

WP2uvrA

Details on mammalian cell type (if applicable):

deficiencies: Histidine (Salmonella) and tryptophan (E. coli)

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 -induced rat liver

Type and composition of metabolic activation system:
- source of S9: Liver microsomal enzymes (S9 homogenate) were purchased from Molecular Toxicology, Inc., Annapolis, MD 2 140 1, Batch 05 15 (40.0 mg of protein per ml). The homogenate was prepared from male Sprague-Dawley rats that had been injected (i.p.) with AroclorTM 1254 (200 mg per ml in corn oil) at 500 mg/kg as described by Ames et al, 1975.
- method of preparation of S9 mix: The S9 mix was prepared immediately prior to its use in any experimental
procedure.
0.70 ml H2O
0.10 ml 1M NaH2P04/Na2HP04, pH7.4
0.02 ml 0.25M Glucose-6-phosphate
0.04 ml 0.10 M NADP
0.04 ml 0.825M KCl/0.2M MgCl2
0.10 ml S9 Homogenate
--> 1.00 ml
- concentration or volume of S9 mix and S9 in the final culture medium: 50 µl vehicle or test article dilution, 100 µl tester strain, 500 µl aliquot of S9 mix
- quality controls of S9 (e.g., enzymatic activity, sterility, metabolic capability): check for sterility by plating 0.5 ml on selective agar

Test concentrations with justification for top dose:

100, 250, 500, 1000, 2500 and 5000 ug/plate

Doses to be tested in the mutagenicity assay were selected based on the results of the dose range finding study conducted on the test article using tester strains TA100 and WP2uvrA in both the presence and absence of S9 mix (one plate per dose). Ten doses of test article, from 5,000 to 6.67 µg per plate, were tested (Experiment 16247-A1). Cytotoxicity was observed with both tester strains TA100 and WP2uvrA at the 3,330 and 5,000 pg per plate doses in both the presence and absence of S9 mix as evidenced by a reduction in the number of revertants per plate and/or a thinning of the bacterial background lawn. No test article precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9 mix.

Vehicle / solvent:

Sterile deionized water (CHV Batch 296,297,298 and 299)

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

- no MA: TA98: 1.0 µg 2-nitrofluorene, TA100, TA 1535: 2.0 µg sodium azide, TA1537: 2.0 µg ICR-191, WP2uvrA: 1.0 µg 4-nitroquinoline-N-oxide. - with MA: TA98, TA100, TA1535, TA1537: 2.5 µg 2-aminoanthracene, WP2uvrA: 25.0 µg 2-aminoanthracene.

Details on test system and experimental conditions:

- Number of replicates: 3 plates/dose
- Pre-incubation time: 20 min. 37 C

NUMBER OF REPLICATIONS:
- Number of cultures per concentration: triplicate
- Number of independent experiments: 2

METHOD OF TREATMENT/ EXPOSURE:
- Test substance added in medium: preincubation

TREATMENT SCHEDULE:
- Preincubation period, if applicable: The test article, the tester strain and the S9 mix (or phosphate buffer, where appropriate) were preincubated for 20 +/- 2 minutes at 37 +/- 2°C prior to the addition of molten, selective overlay agar.
- Exposure duration/duration of treatment: The agar and the preincubation reaction mixture were mixed and then overlaid onto a minimal agar plate. Following incubation at 37 +/- 2°C for 48 +/- 8 hr, revertant colonies were counted.

METHODS FOR MEASUREMENT OF CYTOTOXICITY
Cytotoxicity was detected as a decrease in the number of revertant colonies per plate and/or by a thinning or disappearance of the bacterial background lawn.

CRITERIA FOR A VALID ASSAY:
1.) Tester Strain Integrity: S. typhimurium (rfa wall mutation, pKM101 Plasmid, characteristic number of spontaneous revertants).
2.) Tester Strain Integrity: E. coli (characteristic number of spontaneous revertants).
3.) Tester Strain Culture Density: density of tester strain cultures were greater than or equal to 0.5 x 10exp9 bacteria per ml and/or had reached a target level of turbidity demonstrated to produce cultures with a density greater than or equal to 0.5 x 10exp9 bacteria per ml.
4.) Positive Control Values: without or with MA at least a 3-fold increase over the mean value of the vehicle control for that strain;
5.) Cytotoxicity: A minimum of three non-toxic doses were required to evaluate assay data.

Rationale for test conditions:

- highest test concentration: 5000 µg/plate, which is the recommended maximum test concentration for soluble non-cytotoxic substances in the OECD TG471.
- dose range findings study with 10 concentrations: 6.67, 10, 33.3, 66.7, 100, 333, 667, 1000, 3330, 5000 µg/plate TA100 and WP2uvrA
- preincubation study with 6 concentrations: 100, 250, 500, 1000, 2500, 5000 µg/plate.

Evaluation criteria:

CRITERIA FOR A POSITIVE RESPONSE
For a test article to be considered positive, it had to produce at least a 3-fold increase in the mean
revertants per plate of at least one tester strain over the mean revertants per plate of the
appropriate vehicle control. This 3-fold or greater increase in the mean number of revertants per
plate had to be observed at more than one dose and had to be accompanied by a dose response to
increasing concentrations of the test article. In addition, the observed dose-responsive increase
had to be shown to be reproducible. An observed response which did not meet all three of the
above criteria (magnitude, dose-responsiveness, reproducibility) was not evaluated as positive.

Statistics:

mean revertants per plate +/- standard deviation

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

with MA: >= 2500 µg/plate; without MA: 5000 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

with MA: >= 2500 µg/plate; without MA: 5000 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

with MA: >= 2500 µg/plate; without MA: 5000 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

with MA: >= 2500 µg/plate; without MA: 5000 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

with MA: >= 2500 µg/plate; without MA: 5000 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

- with MA: >= 2500 µg/plate normal-slightly reduced background lawn;
- without MA: 5000 µg/plate moderately-extremely reduced background lawn

Result tables: see attached pdf in section "Overall remarks, attachments"

Conclusions:

Not mutagenic

Executive summary:

The results of the Salmonella - Escherichia colilMammalian-Microsome Reverse Mutation Assay, Preincubation Method with a Confirmatory Assay, indicate that under the conditions of this study, in both an initial and a confirmatory assay, the test article, Monoisopropanolamine, did not cause a positive increase in the number of revertants per plate of tester strains TA98, TA100, TA1535, TA1537, or WP2uvrA either in the presence or absence of microsomal enzymes prepared from AroclorTM-induced rat liver up to the highest dose of 5000 µg/plate tested.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

Haworth S, Lawlor T, Mortelmans K, Speck W, Zeiger E (1983): Salmonella mutagenicity results for 250 chemicals. Environ Mutagen S[Suppl 1]:3-142.

Deviations:

yes

Remarks:

No E.coli strain or TA102 tested; lower purity compared to other Ames tests

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Aldrich
- Purity: 96.4%

Target gene:

Strain Target Gene:
TA1537 hisC3076
TA1535 hisG46
TA100 hisG46
TA98 hisD3052

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

The S9 fractions were prepared from the liver of Aroclor 1254-induced male Sprague-Dawley rats and male Syrian hamsters.

Test concentrations with justification for top dose:

33 - 4000 ug/plate

Vehicle / solvent:

water

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

other: For strains tested with S9: All strains, 2-aminoanthracene.

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 2 days
DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

Evaluation criteria:

According to Haworth et al. (1983).

Species / strain:

S. typhimurium, other: TA98, TA100, TA1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Slightly toxic at highest dose in the 3 strains.

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Slightly toxic at highest dose

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

ambiguous

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Slightly toxic at highest dose

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Result tables: see attached pdf in section "Overall remarks, attachments". 

Conclusions:

Under the conditions tested the test substance was not mutagenic in the strains TA98, TA100 and TA1537 with and without metabolic activation. With S9 mix from hamster liver, but neither without nor with S9 mix from rat liver, the TA1535 strain presented some weak positive results. However, there were only low level dose responses, occurring in the presence of slight toxicity and/or the respective solvent control value was rather low. Therefore, the test substance was rated as ambiguous / questionable under these test conditions.

Reference 3

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

Ames et al., Mut Res 31, 347-364, 1975

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Analytical purity: 97%
- Supplier: Tokyo Kasei Kogyo Co. LTD. Tokyo, Japan

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Details on mammalian cell type (if applicable):

CELLS USED
- Type and source of cells: S. typhimurium provided by B.N. Ames, U.S .A.; E. coly provided by M. Ishizawa, Japan

MEDIA USED
- Type and composition of media, CO2 concentration, humidity level, temperature:
- S9 mix or sodium phosphate buffer (pH 7.4) for preincubation
- minimal glucose agar
- 37°C

Species / strain / cell type:

S. typhimurium TA 1538

Details on mammalian cell type (if applicable):

CELLS USED
- Type and source of cells:
S. typhimurium provided by B.N. Ames, U.S .A.

MEDIA USED
- Type and composition of media, CO2 concentration, humidity level, temperature:
- S9 mix or sodium phosphate buffer (pH 7.4) for preincubation
- minimal glucose agar
- 37°C

Metabolic activation:

with and without

Metabolic activation system:

S9-mix from the liver of male Sprague-Dawley rats, pretreated with polychlorinated biphenyl (KC 500) at a dose of 500 mg/kg body weight five days before sacrifice.

Test concentrations with justification for top dose:

1 - 5000 ug/plate

Vehicle / solvent:

water

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

2-nitrofluorene

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

other: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide, 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

Species / strain:

other: TA98, TA100, TA1535, TA1537, E. coli WP2 uvrA

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Result table see attached pdf in next section "Overall remarks, attachments". 

 

Abbreviations for positive controls: 

AF2: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide, ENNG: N-ethyl-N'-nitro-N-nitrosoguanidine, 9AC: 9-aminoacridine, 4NQO: 4-nitroquinoline-l-oxide, B(a)P: benzo(a)pyrene, 2AA: 2-aminoanthracene

Conclusions:

The reverse bacterial gene mutation test for MIPA is negative.

Reference 4

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

GLP compliance:

yes

Type of assay:

in vitro mammalian cell gene mutation test using the Hprt and xprt genes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: The Dow Chemical Co., Midland, MI, lot MM930105
- Purity: 99.63%
- Purity test date: 1994

Target gene:

HGPRT locus

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Remarks:

-K1-BH-4

Details on mammalian cell type (if applicable):

Proficiences: low spontaneous mutation frequency at the HGPRT locus.

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9 : purchased from Sitek Research Laboratories, Rockville, MD, USA
- method of preparation of S9 mix : liver homogenates prepared from Aroclor-1254 treated (500 mg/kg) male Sprague-Dawley rats
- concentration or volume of S9 mix and S9 in the final culture medium : 10% (v/v)

Test concentrations with justification for top dose:

156.3-2500 µg/ml
Number of replicates: 2
Analytical method: GC/HPLC

Vehicle / solvent:

water

Untreated negative controls:

no

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

other: with S9: 20-Methylcholanthrene, final conc.: 4µg/mL

Details on test system and experimental conditions:

HGPRT assay
- Application: Cells were treated for approximately 4 hours. Then, cells were subcultured into petri dishes (1x10E6/dish). This was repeated every 2-3 days up to 7-8 days. Then the cells were trypsinised and plated in selection medium (2x10E5 cells/dish). Mutant frequency was determined 8-10 days later.

Evaluation criteria:

Based on statistical evaluation.

DESCRIPTION OF FOLLOW UP REPEAT STUDY: repeat study was similar to first study.

Statistics:

- frequency of mutants per 10E6 clonable cells: ANOVA
- actual plate counts: follow a poisson distribution
- mean plate count is used as an estimate of variance
- linear trend test and lack of fit test are employed (α=0.05) as an omnibus test to compare treated groups to the negative control
- if significant increasing trend or a significant lack of fit: Dunnett’s t-test is conducted, comparing each treated group and the positive control to the negative control (α=0.05, one-sided)
- additional comparison of the positive control to the negative control (α=0.05): linear contrast statement

- acceptance criteria: the mutation frequency in positive controls should be significantly higher than the negative controls, and the negative controls should be within reasonable limits of laboratory historical controls and literature values
- chemical considered positive: statistically significant, dose related, reproducible increase in mutation frequency induced
- final interpretation of the data: mutation frequency and cloning efficiencies in the negative controls

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

at the highest concentration

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS:
Highest dose was based on changes in pH/osmolality. pH at 2500 ug/mL was 9.19. This was lowered to 7.40 (pH of control was 7.05). Osmolality 307 mOsmol/kg water versus 257 in the control. Higher concentrations needed more HCl to adjust the pH, revealing an unacceptably high osmolality.

Table 1: Survival of CHO cells (passage 29) treated with the test chemical.

		Without S-9				With S-9
		No. of Colonies Per Dish				No. of Colonies Per Dish
Treatment(µg/ml)	1	2	3	RCS(%) a	1	2	3	RCS(%) a
Neg. control b	166	163	147	100.0	102	148	142	100.0
39.06	166	147	152	97.7	111	125	123	91.6
78.13	131	132	136	83.8	115	114	131	91.8
156.25	171	157	163	103.2	120	120	106	88.3
312.50	124	142	136	84.5	146	123	121	99.5
625.00	142	160	139	92.6	128	106	130	92.9
1250.00	137	162	123	88.7	111	91	133	85.5
2500.00	140	107	122	77.5	124	122	112	91.3

a: Relative cell survival (%) = (mean number of colonies / dish in the treated*100) / (Mean number of colonies / dish in the negative control)

b: 1% water

Table 2: Results of the gene mutation assay in the abscence of S-9, Assay 1. Positive control: 621 µg/mL EMS. Negative control: 1% water.

Toxicity Assay					Mutation Assay											Cloning Efficiency (CE)
	Colonies/Dish				TGr Colonies/Dish b											Colonies/Dish				TGr Muatants per 1E6 Clonable Cells
Treatment (µg/mL)	1	2	3	RCS(%)a	1	2	3	4	5	6	7	8	9	10	Total	1	2	3	CE(%) c
Neg. Control	122	123	125	104.4	0	0	0	2	1	0	1	0	1	0	5	156	187	163	84.3	3.0
Neg. Control	128	112	99	95.6	2	0	2	1	0	0	0	1	0	0	6	123	162	144	71.5	4.2
156.3	129	136	102	103.5	0	0	0	0	0	1	1	0	1	1	4	114	165	137	69.3	2.9
156.3	125	123	119	103.5	0	0	0	0	0	1	1	1	1	0	4	166	129	185	80.0	2.5
312.5	94	83	97	77.3	4	1	0	1	0	1	1	0	0	0	8	222	251	204	112.8	3.5
312.5	109	109	109	92.2	0	2	0	1	3	2	0	1	1	2	12	123	155	128	67.7	8.9
625.0	107	128	107	96.5	0	0	0	1	0	2	0	0	0	0	3	144	102	146	65.3	2.3
625.0	89	94	94	78.1	0	0	0	0	1	0	0	0	0	0	1	137	133	111	63.5	0.8
1250.0	106	118	112	94.8	0	0	0	0	0	0	1	0	1	1	3	134	149	145	71.3	2.1
1250.0	105	108	115	92.5	2	1	0	0	1	1	1	0	0	1	7	153	147	157	76.2	4.6
2500.0	74	68	58	56.4	0	0	0	0	0	0	0	0	0	0	0	135	119	158	68.7	0.0
2500.0	80	53	62	55.0	2	0	1	3	0	3	4	1	2	3	19	134	149	132	69.2	13.7
Pos. Control	15	25	26	18.6	20	17	16	18	28	26	27	30	20	21	223	42	28	41	18.5	602.7 d
Pos. Control	22	21	18	17.2	17	13	12	17	23	22	20	14	14	9	161	42	56	62	26.7	301.9 d

a: Relative cell survival (%)= (Mean number of colonies / dish in the treated) / (Mean number of colonies/ dish in the negative control [avg. of replicates]) * 100

b: TGr = 6-Thioguanine resistant

c: CE(%) = (Mean number of colonies/dish) / (No. of cells seeded/dish) * 100

d: The frequency of TGr mutants is significantly higher than the concurrent negative control value (alpha=0.05).

Table 3: Results of the gene mutation assay in the abscence of S-9, Assay 2. Positive control: 621 µg/mL EMS. Negative control: 1% water.

Toxicity Assay					Mutation Assay											Cloning Efficiency (CE)
	Colonies/Dish				TGr Colonies/Dish b											Colonies/Dish				TGr Muatant per 1E6 Clonable Cells
Treatment (µg/mL)	1	2	3	RCS(%) a	1	2	3	4	5	6	7	8	9	10	Total	1	2	3	CE(%) c
Neg. Control	116	102	137	97.7	1	1	0	2	3	2	0	0	0	0	9	221	192	199	102.0	4.4
Neg. Control	124	113	135	102.3	0	0	0	1	0	1	0	0	0	0	2	186	160	189	89.2	1.1
156.3	108	123	97	90.2	0	1	0	1	0	0	0	0	0	0	2	206	174	196	96.0	1.0
156.3	122	144	123	107.0	2	1	1	2	1	1	0	4	0	2	14	187	177	171	89.2	7.9
312.5	118	128	106	96.8	2	2	2	2	3	2	3	4	2	1	23	207	191	188	97.7	11.8
312.5	143	127	97	101.0	0	1	1	0	0	1	1	0	0	1	5	163	195	178	89.3	2.8
625.0	141	161	142	122.1	0	2	0	5	1	8	1	1	0	0	18	229	241	223	115.5	7.8
625.0	145	126	103	102.9	1	1	1	0	0	5	1	1	0	3	13	214	184	190	98.0	6.6
1250.0	179	146	131	125.4	2	0	0	0	0	0	1	0	0	1	4	211	221	198	105.0	1.9
1250.0	84	117	8.5	78.7	3	2	3	1	1	3	2	1	2	1	19	214	205	214	105.5	9.0
2500.0	106	119	140	100.4	0	0	2	2	0	1	0	3	1	0	9	208	207	171	97.7	4.6
2500.0	124	121	134	104.3	1	0	0	0	1	1	1	1	1	0	6	178	182	198	93.0	3.2
Pos. Control	45	43	48	37.4	40	41	26	30	37	32	34	40	29	24	333	82	91	98	45.2	368.6 d
Pos. Control	36	47	34	32.2	41	47	41	49	38	37	26	55	35	33	402	112	100	97	51.5	390.3 d

a: Relative cell survival (%)= (Mean number of colonies / dish in the treated) / (Mean number of colonies/ dish in the negative control [avg. of replicates]) * 100

b: TGr = 6-Thioguanine resistant

c: CE(%) = (Mean number of colonies/dish) / (No. of cells seeded/dish) * 100

d: The frequency of TGr mutants is significantly higher than the concurrent negative control value (alpha=0.05).

Table 4: Results of the gene mutation assay in the presence of S-9, Assay 1. Positive control: 4 µg/mL 20-MCA. Negative control: 1% water.

Toxicity Assay					Mutation Assay											Cloning Efficiency (CE)
	Colonies/Dish				TGr Colonies/Dish b											Colonies/Dish				TGr Muatant per 1E6 Clonable Cells
Treatment (µg/mL)	1	2	3	RCS(%) a	1	2	3	4	5	6	7	8	9	10	Total	1	2	3	CE(%) c
Neg. Control	81	68	70	103.8	0	0	0	1	0	0	0	0	0	0	1	104	126	102	55.3	0.9
Neg. Control	67	70	66	96.2	2	2	1	0	1	2	2	0	1	1	12	127	143	118	64.7	9.3
156.3	88	66	61	101.9	0	0	0	0	0	1	1	0	0	1	3	134	112	107	58.8	2.5
156.3	98	74	78	118.5	0	0	1	1	1	0	0	1	1	1	6	123	119	143	64.2	4.7
312.5	90	89	78	121.8	1	2	1	0	1	2	0	0	1	0	8	119	156	114	64.8	6.2
312.5	84	70	72	107.1	1	0	1	0	0	0	0	0	1	0	3	141	148	154	73.8	2.0
625.0	58	63	64	87.7	1	0	2	1	1	1	0	1	0	1	8	139	120	129	64.7	6.2
625.0	74	69	61	96.7	0	0	0	0	1	0	0	0	0	1	2	114	138	173	70.8	1.4
1250.0	70	68	74	100.5	- d	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
1250.0	74	61	57	91.0	0	1	1	0	0	1	0	0	0	0	3	155	123	143	70.2	2.1
2500.0	58	45	55	74.9	0	0	0	0	0	0	1	0	0	0	1	144	135	135	69.0	0.7
2500.0	70	74	79	105.7	0	0	0	0	0	0	0	0	0	0	0	123	130	150	67.2	0.0
Pos. Control	65	68	76	99.1	16	20	14	16	12	16	17	6	17	15	149	108	106	111	54.2	137.5 e
Pos. Control	63	61	67	90.5	14	20	11	13	12	21	24	12	18	19	164	90	97	105	48.7	168.5 e

a: Relative cell survival (%)= (Mean number of colonies / dish in the treated) / (Mean number of colonies/ dish in the negative control [avg. of replicates]) * 100

b: TGr = 6-Thioguanine resistant

c: CE(%) = (Mean number of colonies/dish) / (No. of cells seeded/dish) * 100

d: Data lostdueto technical error.

e: The frequency of TGr mutants is significantly higher than the concurrent negative control value (alpha=0.05).

Table 5: Results of the gene mutation assay in the presence of S-9, Assay 2. Positive control: 4 µg/mL 20-MCA. Negative control: 1% water.

Toxicity Assay					Mutation Assay											Cloning Efficiency (CE)
	Colonies/Dish				TGr Colonies/Dish b											Colonies/Dish				TGr Muatant per 1E6 Clonable Cells
Treatment (µg/mL)	1	2	3	RCS(%) a	1	2	3	4	5	6	7	8	9	10	Total	1	2	3	CE(%) c
Neg. Control	122	148	133	87.3	1	1	1	0	0	4	1	1	0	1	10	172	195	170	89.5	5.6
Neg. Control	112	200	208	112.7	3	0	0	0	0	0	0	0	2	2	7	166	111	125	67.0	5.2
156.3	218	184	189	128.1	1	0	1	1	2	0	1	1	0	2	9	185	223	231	106.5	4.2
156.3	159	138	162	99.5	1	1	0	1	1	2	0	1	1	0	8	171	180	206	92.8	4.3
312.5	137	152	150	95.1	1	0	0	1	1	2	1	5	1 ,	0	12	213	205	201	103.2	5.8
312.5	104	125	122	76.1	0	0	0	0	0	0	0	1	1	0	2	180	200	209	98.2	1.0
625.0	109	120	138	79.5	0	0	0	0	1	2	0	0	1	0	4	225	226	193	107.3	1.9
625.0	139	114	133	83.6	3	1	1	3	1	2	0	1	1	0	13	217	209	210	106.0	6.1
1250.0	105	95	97	64.4	0	3	1	1	0	0	0	1	0	0	6	227	198	187	102.0	2.9
1250.0	99	81	95	59.6	0	0	1	1	2	0	0	0	1	1	6	227	223	225	112.5	2.7
2500.0	81	81	98	56.3	0	0	2	0	1	1	0	0	0	4	8	183	189	206	96.3	4.2
2500.0	75	79	74	49.4	1	3	1	2	2	3	6	2	1	2	23	207	186	206	99.8	11.5
Pos. Control	84	87	98	58.3	42	42	41	35	30	38	41	34	24	23	350	184	154	165	83.8	208.7d
Pos. Control	97	90	93	60.7	32	43	24	38	29	41	32	24	21	38	322	176	178	155	84.8	189.8d

a: Relative cell survival (%)= (Mean number of colonies / dish in the treated) / (Mean number of colonies/ dish in the negative control [avg. of replicates]) * 100

b: TGr = 6-Thioguanine resistant

c: CE(%) = (Mean number of colonies/dish) / (No. of cells seeded/dish) * 100

d: The frequency of TGr mutants is significantly higher than the concurrent negative control value (alpha=0.05).

Conclusions:

The forward mammalian gene mutation assay in the chinese hamster overay cell/Hypoxanthine-Guanine-Phosphoribosyl transferase (CHO/HGPRT) for MIPA is negative.
Under the conditions tested the substance was not mutagenic in a HGPRT assay in CHO cells.

Reference 5

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

OECD (1983)

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: The Dow Chemical Co., Midland, MI, lot MM930105
- Purity: 99.63%
- Purity test date: 1994

Species / strain / cell type:

lymphocytes: rat lymphocytes

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: blood sample collection from Sprague-Dawley rats
- Suitability of cells: The laboratory rat is widely used for toxicologieal studies and hence the results of the in vitro cytogenetic tests can be compared with other toxicological end points. Since rats can be maintained in well controlled environments, the influence of environmental factors on the end point being measured ean be controlled. The karyotype of cultured rat lymphocytes (2N=42) is stable as opposed to the relative karyotypic instability of established cell lines. Furthermore, with the rat lymphocyte system, S-9 preparations from the same species ean be used for metabolite activation.

For lymphocytes:
- Sex, age and number of blood donors: male, 17-18 weeks, number of animals not specified
- whole blood cultures used
- blood from different donors were pooled

MEDIA USED
- Type and composition of media, CO2 concentration, temperature:
- RPMI 1640 medium (with 25 mM HEPES, GIBCO, Grand Island, NY) + 10% heat-inactivated fetal bovine serum (GIBCO) + Fungizone 0.25 Ilg/ml; penicillin G, 100 u/ml; and streptomycin sulfate, 0.1 mg/ml (GIBCO) + 20 Ilg/ml PHA (HA17, Murex Diagnostics Ltd.,Dartford, England) + 2 mM L-glutamine (GIBCO)
- 37°C

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9: purchased from Sitek Research Laboratories, Rockville, MD, USA
- method of preparation of S9 mix: liver homogenates prepared from Aroclor-1254 treated (500 mg/kg) male Sprague-Dawley rats
- concentration or volume of S9 mix and S9 in the final culture medium : 10% (v/v)

Test concentrations with justification for top dose:

Assay 1, presence of S-9
2.5, 8.3, 25, 83.3, 250, 833, 2500 µg/mL
Assay 1, abscence of S-9
2.5, 8.3, 25, 83.3, 250, 833, 2500 µg/mL
Assay 2, presence of S-9
250, 833, 2500 µg/mL
Assay 2, abscence of S-9
83.3, 250, 833, 1500 µg/mL

Analytical method: GC/HPLC

Vehicle / solvent:

- Vehicle used: water

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

water

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Details on test system and experimental conditions:

ADMINISTRATION:
-Treatment time/harvest time:
-S9-mix: 24/24 hours and 48/48 hours (second test)
+S9-mix: 4/24 hours and 4/48 hours (second test)
- Dosing;
-S9-mix: 2.5, 8.33, 25.0, 83.3, 250, 833, 2500 ug/mL
(first test)
-S9-mix: 83.3, 250, 833, 1500 ug/mL (second test)
+S9-mix: 2.5, 8.33, 25.0, 83.3, 250, 833, 2500 ug/mL
(first test)
+S9-mix: 83.3, 250, 833, 2500 ug/mL (second test)
-Doses used for evaluation
-S9-mix: 83.3, 250, 833 ug/mL (first test)
-S9-mix: 250, 833, 1500 ug/mL (24 h harvest)
1500 ug/ml (48 h harvest) (second test)
+S9-mix: 250, 833, 2500 ug/mL (first test)
+S9-mix: 250, 833, 2500 ug/mL (24 h harvest)
2500 ug/mL (48 h harvest) (second test)
- Number of replicates: 2

Mitotic index: based on 1000 cells.
No. of metaphases analyzed: 100 metaphases/replicate (200/dose).

Evaluation criteria:

- Statistically significant increase in the aberrant cells frequency, with or without S9-mix

Statistics:

- At each dose level, data from the replicates were pooled
- A 2-way contingency table was constucted to analyze the frequencies of cytogenetic abnormalities. An overall Chi-square statistic, based on the table, was partitioned into components of interest.
- Two global hypotheses: (1) no differences in average number of cells with aberrations among the dose groups, and (2) no linear trend of increasing number of cells with aberrations with increasing dose
- ordinal metric used for the doses in the statistical evaluation
- If either statistic was found to be significant at α=0.01 versus a one-sided increasing alternative, pairwise tests (i.e., control vs treatment) were performed at each dose level and evaluated at α=0.01 again versus a one-sided alternative.
- Acceptance criteria: The chromosomal aberration frequency in the positive control cultures should be significantly higher than the negative controls, the aberration frequency in the negative control should be within reasonable limits of the laboratory historical values.
- considered positive in this assay if it induces a significant dose-related, and reproducible increase in the frequency of cells with aberrations

Species / strain:

lymphocytes: primary cultures from the rat

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: Without metabolic activation: 833 ug/mL (Assay 1), 1500 µg/mL (Assay 2); With metabolic activation: no toxicity up to 2500 ug/mL

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

True negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

GENOTOXIC EFFECTS:
- with metabolic activation: no effects
- without metabolic activation: no effects
MITOTIC INDEX:
- Without metabolic activation (shown as % change of MI compared to controls)
- 1500 ug/mL (24h): 78% of the control
- 1500 ug/mL (48 h): 86% of the control
- With metabolic activation
- 2500 ug/mL (24h and 48h): no significant reduction.

TEST-SPECIFIC CONFOUNDING FACTORS:
Highest dose was based on changes in pH/osmolality. pH at 2500 ug/mL was too high and was lowered to approximately 7.4. Osmolality at 2500 ug/mL was at an acceptable level (55-57 mOsmol/kg water above the control). Higher concentrations needed more HCl to adjust the pH, revealing an unacceptably high osmolality.

The following tables only show the confirmation assays (second round assays).

Table 1: Mitotic indicies (M.I.) of cell cultures treated with MIPA in the abscence of S-9

	% M.I. Harvested 24 h After Treatment			% M.I. Harvested 48 h After Treatment
	Replicate	Replicate	Average	Replicate	Replicate	Average
Dose µg/ml	A	B	A+B	A	B	A+B
Negative control a	7.3	9.3	8.3	6.3	5.8	6.1
83.3	10.2	8.0	9.1	8.8	6.9	7.9
250.0	8.5	10.3	9.4	7.3	6.8	7.1
833.0 b	7.9	5.9	6.9	3.4	3.7	3.6
1500.0 b	7.0	6.0	6.5	4.1	6.3	5.2
Positive control c	3.9	4.1	4.0	ND	ND	ND
Positivecontrol d	3.2	4.0	3.6	ND	ND	ND

a: 1% Water

b: 2N HCl was added to adjust the pH of the treatment medium.

c: MMC (0.05 µg/ml)

d: MMC (0.075 µg/ml)

ND: Not Done

Table 2: Mitotic indicies (M.I.) of cell cultures treated with MIPA in the presence of S-9

	% M.I. Harvested 24 h After Treatment			% M.I. Harvested 48 h After Treatment
	Replicate	Replicate	Average	Replicate	Replicate	Average
Dose µg/ml	A	B	A+B	A	B	A+B
Negative control a	9.2	13.0	11.1	4.5	6.2	5.4
250.0	6.0	7.6	6.8	8.6	6.2	7.4
833.0 b	9.1	11.0	10.1	9.0	9.1	9.1
2500.0 b	11.5	12.1	11.8	5.9	7.8	6.9
Positive control c	1.6	1.8	1.7	ND	ND	ND

a: 1% Water

b: 2N HCl was added to adjust the pH of the treatment medium.

c: CP (6 µg/ml)

ND: Not Done

Table 3: Results of the chromosomal aberration assay 24h after treatment in the abcence of S-9

Test Chemical: MIPA, Negative Control: 1% Water, Positive Control: (0.075 µg/ml MMC)

	Neg. Control			250 µg/ml			833 µg/ml			1500µg/ml			Pos. Control
	A	B	A+B	A	B	A+B	A	B	A+B	A	B	A+B	A	B	A+B
No. of cells scored	100	100	200	100	100	200	100	100	200	100	100	200	100	100	200
Chromatid Gaps	0	4	4	4	4	8	6	6	12	7	7	14	10	11	21
Chromosome Gaps	0	2	2	1	0	1	1	0	1	1	5	6	3	15	18
Chromatid Breaks	2	1	3	0	3	3	1	0	1	0	9	9	14	19	33
Chromatid Exchanges	0	0	0	0	0	0	0	0	0	0	0	0	15	7	22
Chromosome Breaks	0	0	0	0	0	0	0	0	0	1	0	1	8	9	17
Chromosome Exchanges	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Total Aberrations	2	1	3	0	3	3	1	0	1	1	9	10	37	36	73
(excluding gaps) a			(1.5)			(1.5)			(0.5)			(5.0)			(36.5)
No. of cells with Aberr.	2	1	3	0	3	3	1	0	1	1	8	9	24	32	56 b
(excluding gaps) a			(1.5)			(1.5)			(0.5)			(4.5)			(28.0)
Miscellaneous Aberr.	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1
Cells with Multiple Aberr. (5 or more aberr.)	0	0	0	0	0	0	0	0	0	0	0	0	1	0	1

a: Values in parentheses are percentages.

b: Significantly (alpha<0.01) different from the negative control.

Table 3: Results of the chromosomal aberration assay 24h after treatment in the presence of S-9

Test Chemical: MIPA, Negative Control: 1% Water, Positive Control: (6 µg/ml CP)

	Neg. Control			250 µg/ml			833 µg/ml			2500 µg/ml			Pos. Control
	A	B	A+B	A	B	A+B	A	B	A+B	A	B	A+B	A	B	A+B
No.of cells scored	100	100	200	100	100	200	100	100	200	100	100	200	100	100	200
Chromatid Gaps	2	0	2	1	4	5	3	0	3	1	0	1	42	35	77
Chromosome Gaps	0	1	1	1	1	2	1	1	2	1	1	2	15	22	37
Chromatid Breaks	2	1	3	0	1	1	1	1	2	0	0	0	29	24	53
Chromatid Exchanges	0	0	0	0	0	0	0	0	0	0	0	0	59	45	104
Chromosome Breaks	0	0	0	0	1	1	0	0	0	0	1	1	34	24	58
Chromosome Exchanges	0	0	0	0	0	0	0	0	0	0	0	0	0	2	2
Total Aberrations	2	1	3	0	2	2	1	1	2	0	1	1	122	95	217
(excluding gaps) a			(1.5)			(1.0)			(1.0)			(0.5)			(108.5)
No. of cells with Aberr.	2	1	3	0	2	2	1	1	2	0	1	1	61	60	121 b
(excluding gaps) a			(1.5)			(1.0)			(1.0)			(0.5)			(60.5)
Miscellaneous Aberr.	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Cells with Multiple Aberr.	0	0	0	0	0	0	0	0	0	0	0	0	2	5	7
(5 or more aberr.)

a: Values in parentheses are percentages.

b: Significantly (alpha<0.01) different from the negative contral.

Conclusions:

The test material, MIPA, did not induce a significant increase in the frequency of cells with chromosomal abnormalities. Hence, it was concluded that under the experimental conditions used, MIPA was negative in this in vitro chromosomal aberration test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

MIPA was found not mutagenic in an in vivo Drosophila SLRL study upon feeding (24000 ppm MIPA) or injection (1900 ppm).

Link to relevant study records

Reference

Endpoint:

in vivo mammalian germ cell study: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 477 (Genetic Toxicology: Sex-linked Recessive Lethal Test in Drosophila melanogaster)

Version / remarks:

The guideline is not specified but given the scientific description of the study, performance similar to OECD 477 is suggested.

Principles of method if other than guideline:

Method: Woodruff, RC et al., Env. Mutagen., 6, 189-202.
Adult Canton-S males were subjected to a 3 day feeding exposure. They were mated to Basc females using a 2 to 3 day brooding pattern for a total of
three broods spanning 7 days. If the feeding sex-linked recessive lethal (SLRL) test was negative, an injection exposure was performed. As in the feeding exposure, a 2 to 3 day brooding pattern for three broods was used.

GLP compliance:

not specified

Type of assay:

Drosophila SLRL assay

Specific details on test material used for the study:

- Purity: 96.4 %
- Supplier: Aldrich (3803 LE)

Species:

Drosophila melanogaster

Strain:

other: Canton S

Sex:

male

Route of administration:

other: In feed. If the results of the feeding SLRL test were negative, an injection exposure was performed.

Vehicle:

Water

Duration of treatment / exposure:

feeding study: 3 days; If the results of the feeding SLRL test were negative, a single injection exposure was performed.

Frequency of treatment:

continuously in feed

Dose / conc.:

24 250 ppm

Remarks:

feeding study

Dose / conc.:

1 940 ppm

Remarks:

injection

No. of animals per sex per dose:

no data

Control animals:

yes, concurrent no treatment

Evaluation criteria:

A minimum of approximately 5,000 chromosomes were scored in each of the treated and concurrent control groups, unless the mutant frequency exceeded 1%. Clusters were identified using the Poisson distribution (Owen, 1962) and were removed before analysis.

Statistics:

The statistical evaluation of a SLRL test included a comparison with the concurrent solvent control using the normal approximation to the binomial distribution, as presented by Margolin et al. (1983), as well as a comparison with the historical control as described by Mason et al. (1992). In order to be considered mutagenic, the mutant frequency in the treated sample must exceed 0.15% with a P value of less than 0.05, or the treated frequency must exceed 0.1% with a P value of less than 0.01. If the treated frequency was between 0.1% and 0.15% and the P value was between 0.1 and 0.01; or if the treated frequency was higher than 0.15%, and the P value was between 0.1 and 0.05 the assay was considered equivocal. All other assays were considered negative.

Sex:

male

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

not specified

Table 1: Results of the drosophila testing in Mono-isopropanolamin.

Dose (ppm)	ROA	Percent mortality	Percent sterility	Lethals			Tests			Total lethals	Total tests	Percent lethals
				Br 1	Br 2	Br 3	Br 1	Br 2	Br 3
24,000	feeding	5	17	1	0	2	2,658	1,421	847	3	4,926	0.06
0				1	0	1	2,875	2,748	2,414	2	8,037	0.02
1,900	injection	14	8	2	2	2	1,911	1,675	1,562	6	5,148	0.12
0				0	2	0	1,739	1,493	1,079	2	4,311	0.05

One cluster of 3 in the injection control and one of 4 in the treated feeding experiment

Conclusions:

Under the conditions tested the test substance was not mutagenic in a Drosophila SLRL assay.
Thus, MIPA is not considered to be genotoxic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Mode of Action Analysis / Human Relevance Framework

No information available.

Additional information

IN VITRO TESTS

Bacterial mutation testing

The results of the Salmonella - Escherichia coli/Mammalian-Microsome Reverse Mutation Assay (1996; in line with OECD471, under GLP), indicate that under the conditions of this study (preincubation method), in both an initial and a confirmatory assay, the test article, Monoisopropanolamine, did not cause a positive increase in the number of revertants per plate of tester strains TA98, TA100, TA1535, TA1537, or WP2uvrA either in the presence or absence of metabolic activation up to the highest dose of 5000 µg/plate tested.

Supportingly, in the Ames test by Shimizu et al. (1985) MIPA was found not mutagenic in S. typhimurium strains TA98, TA100, TA 1535, TA1537 and TA 1538, and E. coli WP2 uvr A, incubated with 1 to 5000 µg MIPA/plate in the presence and absence of metabolic activation. Cytotoxicity was observed at the highest dose only. 

MIPA was also tested in the Ames reverse mutation assay by Zeiger et al. (1987), using S. typhimurium strains TA98, TA100, TA1535 and TA1537 at 33 to 4000 µg/plate with and without metabolic activation. MIPA was slightly cytotoxic at the higher concentrations. The test substance was not mutagenic in the strains TA98, TA100 and TA1537 with and without metabolic activation. With metabolic activation, the TA1535 strain presented some weak positive results. However, there were only low level dose responses, occurring in the presence of slight toxicity and/or the respective solvent control value was rather low. Therefore, the test substance was rated as ambiguous / questionable under these test conditions.
The substance purity in this Ames test was about 96%, whereas substance purity in the other Ames tests with negative results was higher. Therefore, impurities are likely to be responsible for this ambiguous result.

Taken together, the test-substance is considered to be not mutagenic in bacterial mutation testing.

Mammalian cell gene mutation testing

Induction of gene mutations in mammalian cells was investigated in an HGPRT assay (1995; according to OECD476, under GLP) using Chinese hamster ovary (CHO) cells at 156 to 2500 µg/mL, with and without metabolic activation. The results indicate that MIPA did not result in gene mutations in this assay. No cytotoxicity was observed. Overall, MIPA is considered not to induce gene mutations.

MIPA tested at 83 - 1500 µg/mL (-S9) and 250 - 2500 µg/mL (+S9) did not induce significant increases in chromosomal aberrations using rat lymphocytes with and without metabolic activation (1995; according to OECD473, under GLP). Cytotoxicity was observed without metabolic activation only, at 833 µg/mL. MIPA was judged non-clastogenic.

 

Since no genotoxic properties were revealed in the in vitro studies, no in vivo genotoxicity study is needed for MIPA.

 

IN VIVO TESTING

An in vivo sex-linked recessive lethal (SLRL) assay was performed in Drosophila melanogaster. Adult Canton-S males were subjected to a 3 day feeding exposure to 24000 ppm MIPA. They were mated to Basc females using a 2 to 3 day brooding pattern for a total of three broods spanning 7 days. A minimum of approximately 5000 chromosomes were scored per group unless the mutant frequency exceeded 1%. If the feeding test was negative, an injection exposure (1900 ppm) was performed. MIPA was found not mutagenic in the Drosophila SLRL test under the conditions tested (Foureman et al., 1994).

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for genotoxicity under Regulation (EC) No. 1272/2008.