Potassium hydrogen phthalate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation in vitro:

Ames test:

Ames assay was performed to investigate the potential of Potassium hydrogen phthalate (CAS No. 877-24-7) to induce gene muta­tions in comparison to negative control according to the plate incorporation test (Trial I) and the pre-incubation test (Trial II) using theSalmonella typhimuriumstrains TA 1535, TA 1537, TA 98, TA 100 and TA 102.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the negative and positive controls was tested in triplicate. Based on the solubility and precipitation test results eight different concentrations viz., 0.0 (N.C), 0.002, 0.005, 0.016, 0.050, 0.158, 0.501, 1.582 and 5 mg/plate were selected for pre-experiment.

Based on the pre-experiment results, the test item was tested with the following concentrations: 0 (NC), 0.050, 0.158, 0.501, 1.582 and 5 mg/plate for main study, both in the presence of metabolic activation (+S9) and in the absence of metabolic activation (-S9).

No substantial increase in revertant colony numbers in any of the tester strains were observed following treatment with Potassium hydrogen phthalate (CAS No. 877-24-7) at any dose level in both the confirmatory trials, neither in the presence nor in the absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. The spontaneous reversion rates in the negative and positive controls were within the range of our historical data.

The positive controls used for various strains showed a distinct in­crease in induced revertant colonies in both the methods i.e. Plate incorporation method and Pre-incubation method.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item [Potassium hydrogen phthalate (CAS No. 877-24-7)] did not induce gene mutations by base pair changes or frame shifts in the genome of the strains used.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19-02-2018 - 06-04-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

This study was performed to investigate the potential of Potassium hydrogen phthalate (CAS No. 877-24-7) to induce gene muta¬tions in comparison to negative control according to the plate incorporation test (Trial I) and the pre-incubation test (Trial II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

other:

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced S9 metabolic activation system

Test concentrations with justification for top dose:

0 (NC), 0.050, 0.158, 0.501, 1.582 and 5 mg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: RO (Reverse Osmosis) Water
- Justification for choice of solvent/vehicle: The test chemical was soluble in RO (Reverse Osmosis) Water

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

RO (Reverse Osmosis) Water

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other: 4-Nitro-o-phenylenediamine (TA 1537, TA 98, without S9); 2-Aminoanthracene (TA 1535, TA 1537, TA 98, TA 100 and TA 102, with S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation- Trial I); preincubation (Trial II)

DURATION
- Preincubation period: Trial I: Not applicable Trial II: 60 min
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- 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: Each concentration, including the negative, vehicle and positive controls was tested in triplicate in two independent experiments performed

METHODS OF SLIDE PREPARATION AND STAINING TECHNIQUE USED: Not applicable

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: No data

Rationale for test conditions:

No data

Evaluation criteria:

A test item is considered as a mutagen, if a biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA 98, TA 100 and TA 102) or thrice (strains TA 1535 and TA 1537) the colony count of the corresponding solvent control is observed..

A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.

An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment.

A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative control and vehicle control such an increase is not considered biologically relevant.

Statistics:

No data

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: No data
- Definition of acceptable cells for analysis: No data
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: To evaluate the toxicity of the test item, a pre-experiment was performed with strains TA 98 and TA 100. Eight concentrations ([0.0 (N.C), 0.002, 0.005, 0.016, 0.050, 0.158, 0.501, 1.582 and 5 mg/plate) ] were tested for toxicity and mutation induction with 3 plates each (triplicates). The experimental conditions in this pre-experiment were the same as described below for the Trial-I (Plate incorporation test). Toxicity of the test item results in a reduction in the number of spontaneous revertants or a clearing of the bacterial background lawn.

In the pre-experiment, the concentration range of the test item was 0.002 - 5 mg/plate based on the solubility and precipitation test. In treated concentrations 5 - 0.002 mg/plate (T8-T1) no colony reduction or back ground lawn reduction was observed both, in absence and in the presence of metabolic activation. Based on the results of pre-experiment following doses were selected for the main study trials: 0.0 (N.C), 0.050, 0.158, 0.501, 1.582 and 5 mg/plate, both in the absence (-S9) as well as in the presence of metabolic activation (+S9).

CYTOKINESIS BLOCK (if used)
- Distribution of mono-, bi- and multi-nucleated cells: No data

NUMBER OF CELLS WITH MICRONUCLEI
- Number of cells for each treated and control culture: No data
- Indication whether binucleate or mononucleate where appropriate: No data

HISTORICAL CONTROL DATA (with ranges, means and standard deviation and confidence interval (e.g. 95%)
- Positive historical control data: No data
- Negative (solvent/vehicle) historical control data: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Measurement of cytotoxicity used: No data
- Other observations when applicable: No data

Remarks on result:

other: No mutagenic potential

TABLE1- REVERTANT COUNT FOR PRE-EXPERIMENT

Dose (mg/plate)	R	Without metabolic activation (-S9)		With metabolic activation (+S9)
		TA100	TA 98	TA100	TA 98
NC (0.00)	R1	88	17	91	17
	R2	90	20	96	18
	R3	85	20	90	18
T1 (0.002)	R1	87	17	102	21
	R2	91	18	100	22
	R3	88	20	94	18
T2 (0.005)	R1	83	18	83	19
	R2	94	21	90	15
	R3	97	21	90	19
T3 (0.016)	R1	91	19	92	20
	R2	93	16	88	23
	R3	88	18	84	22
T4 (0.050)	R1	92	22	89	18
	R2	90	22	93	22
	R3	86	20	91	22
T5 (0.158)	R1	93	24	98	17
	R2	91	21	95	20
	R3	96	20	93	21
T6 (0.501)	R1	99	21	96	17
	R2	94	18	94	16
	R3	104	18	88	19
T7 (1.582)	R1	91	23	84	21
	R2	86	17	96	18
	R3	88	19	94	20
T8 (5)	R1	67	15	75	13
	R2	58	14	78	11
	R3	71	11	76	11
PC	R1	1088	786	1668	828
	R2	1133	794	1792	1033
	R3	1129	849	1819	1114

NC           =     Negative control

PC            =     Positive control             

R              =     Replicate

T              =     Test concentration (T8: Highest, T1: Lowest)

4-Nitro-o-phenylenediamine [10μg/plate]: TA 98

Sodium azide [10μg/plate]: TA 100,

2-Aminoanthracene [2.5μg/plate]: TA98, TA100

 

TABLE 2 - REVERTANT COUNT IN PLATE INCORPORATION METHOD (TRIAL I)

Dose (mg/plate)	R	In the presence of Metabolic Activation (+S9)
		TA 1537	TA 1535	TA 98	TA 100	TA 102
NC (0.00)	R1	6	11	17	91	300
	R2	4	15	18	96	299
	R3	10	12	18	90	287
T1 (0.050)	R1	7	11	18	89	296
	R2	4	10	22	93	275
	R3	6	14	22	91	300
T2 (0.158)	R1	8	12	17	98	283
	R2	5	11	20	95	293
	R3	6	13	21	93	296
T3 (0.501)	R1	7	12	17	96	275
	R2	7	14	16	94	287
	R3	4	10	19	88	280
T4 (1.582)	R1	8	13	21	84	261
	R2	8	13	18	96	275
	R3	4	9	20	94	291
T5 (5)	R1	6	12	13	75	300
	R2	8	14	11	78	292
	R3	9	10	11	76	286
PC	R1	215	455	828	1668	1983
	R2	225	405	1033	1792	1671
	R3	198	568	1114	1819	1834

 

Dose (mg/plate)	R	In the Absence of Metabolic Activation (-S9)
		TA 1537	TA 1535	TA 98	TA 100	TA 102
NC (0.00)	R1	8	13	17	88	289
	R2	10	11	20	90	276
	R3	7	9	20	85	298
T1 (0.050)	R1	6	10	22	92	301
	R2	9	12	22	90	255
	R3	7	10	20	86	286
T2 (0.158)	R1	6	9	24	93	281
	R2	8	8	21	91	273
	R3	9	13	20	96	291
T3 (0.501)	R1	5	11	21	99	256
	R2	4	11	18	94	263
	R3	9	9	18	104	279
T4 (1.582)	R1	4	14	23	91	266
	R2	5	10	17	86	298
	R3	10	8	19	88	274
T5 (5)	R1	10	11	15	67	245
	R2	4	9	14	58	280
	R3	6	12	11	71	274
PC	R1	175	1413	786	1088	1565
	R2	183	1375	794	1133	1681
	R3	203	1441	849	1129	1496

NC= Negative Control,T =Test concentration (T5: Highest, T1: Lowest),R= Replicate

PC= Positive control                                                                       2-Aminoanthracene [2.5μg/plate]: TA 1537, TA1535, TA 98, TA 100        
2- Aminoanthracene [10μg/plate]:TA 102                                             Sodium azide [10μg/plate]: TA 1535, TA 100                                             

4-Nitro-o-phenylenediamine: TA 1537[50μg/plate], TA 98[10μg/plate]      Methyl methanesulfonate [4μl/plate]: TA 102

 

TABLE 3 - REVERTANT COUNT IN PRE-INCUBATION METHOD (TRIAL II)

Dose (mg/plate)	R	In the presence of Metabolic Activation (+S9)
		TA 1537	TA 1535	TA 98	TA 100	TA 102
NC (0.00)	R1	10	16	20	79	281
	R2	6	12	18	115	289
	R3	4	15	18	97	300
T1 (0.050)	R1	4	15	21	97	295
	R2	7	15	16	93	291
	R3	5	11	18	100	283
T2 (0.158)	R1	8	12	17	80	280
	R2	4	15	17	91	255
	R3	7	14	14	80	300
T3 (0.501)	R1	9	16	16	86	281
	R2	8	16	17	97	285
	R3	5	10	20	97	290
T4 (1.582)	R1	5	17	21	101	295
	R2	6	18	23	92	298
	R3	8	10	19	98	300
T5 (5)	R1	7	16	20	83	263
	R2	8	17	17	91	275
	R3	6	17	16	98	280
PC	R1	215	150	1123	1788	1783
	R2	205	163	1046	1810	1891
	R3	198	142	987	1793	1903

 

Dose (mg/plate)	R	In the Absence of Metabolic Activation (-S9)
		TA 1537	TA 1535	TA 98	TA 100	TA 102
NC (0.00)	R1	9	17	18	101	291
	R2	7	13	19	95	255
	R3	8	12	23	89	260
T1 (0.050)	R1	5	10	20	86	272
	R2	9	15	19	100	245
	R3	7	17	15	100	250
T2 (0.158)	R1	6	16	16	115	260
	R2	9	11	17	106	269
	R3	4	14	21	94	280
T3 (0.501)	R1	10	13	22	95	289
	R2	4	11	16	95	281
	R3	6	15	15	89	300
T4 (1.582)	R1	6	16	18	86	255
	R2	7	10	20	80	262
	R3	9	17	20	101	269
T5 (5)	R1	6	14	21	98	270
	R2	5	12	16	100	279
	R3	10	11	14	98	283
PC	R1	155	1563	893	1291	1904
	R2	180	1321	745	1138	1880
	R3	173	1481	901	1197	2032

NC= Negative Control,T =Test concentration (T5: Highest, T1: Lowest),R= Replicate

PC= Positive control                                                                       2-Aminoanthracene [2.5μg/plate]: TA 1537, TA1535, TA98, TA100        
2-Aminoanthracene [10μg/plate]:TA 102                                              Sodium azide [10μg/plate]: TA 1535, TA 100,                                            

4-Nitro-o-phenylenediamine: TA 1537[50μg/plate] TA 98[10μg/plate]        Methyl methanesulfonate [4μl/plate]: TA 102

TABLE 4 - MEAN REVERTANT COUNT IN PLATE INCORPORATION METHOD (TRIALI)

Dose (mg/plate)	In the presence of Metabolic Activation (+S9)
	TA 1537		TA 1535		TA 98		TA 100		TA 102
	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD
NC (0.00)	6.67	3.06	12.67	2.08	17.67	0.58	92.33	3.21	295.33	7.23
T1 (0.050)	5.67	1.53	11.67	2.08	20.67	2.31	91.00	2.00	290.33	13.43
T2 (0.158)	6.33	1.53	12.00	1.00	19.33	2.08	95.33	2.52	290.67	6.81
T3 (0.501)	6.00	1.73	12.00	2.00	17.33	1.53	92.67	4.16	280.67	6.03
T4 (1.582)	6.67	2.31	11.67	2.31	19.67	1.53	91.33	6.43	275.67	15.01
T5 (5)	7.67	1.53	12.00	2.00	11.67	1.15	76.33	1.53	292.67	7.02
PC	212.67	13.65	476.00	83.50	991.67	147.41	1759.67	80.53	1829.33	156.05

 

 

 

Dose (mg/plate)	In the Absence of Metabolic Activation (-S9)
	TA 1537		TA 1535		TA 98		TA 100		TA 102
	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD
NC (0.00)	8.33	1.53	11.00	2.00	19.00	1.73	87.67	2.52	287.67	11.06
T1 (0.050)	7.33	1.53	10.67	1.15	21.33	1.15	89.33	3.06	280.67	23.46
T2 (0.158)	7.67	1.53	10.00	2.65	21.67	2.08	93.33	2.52	281.67	9.02
T3 (0.501)	6.00	2.65	10.33	1.15	19.00	1.73	99.00	5.00	266.00	11.79
T4 (1.582)	6.33	3.21	10.67	3.06	19.67	3.06	88.33	2.52	279.33	16.65
T5 (5)	6.67	3.06	10.67	1.53	13.33	2.08	65.33	6.66	266.33	18.72
PC	187.00	14.42	1409.67	33.13	809.67	34.30	1116.67	24.91	1580.67	93.49

NC= Negative Control,T =Test concentration (T5: Highest, T1: Lowest),SD= Standard Deviation

PC= Positive control

2-Aminoanthracene [2.5μg/plate]: TA 1537, TA 1535, TA 98, TA 100                  Methyl methanesulfonate [4μl/plate]: TA 102

2-Aminoanthracene [10μg/plate]:TA 102                                           

Sodium azide [10μg/plate]: TA 1535, TA 100

4-Nitro-o-phenylenediamine: TA 1537[50μg/plate], TA 98 [10μg/plate]

 

 

 

 

TABLE 5 - MEAN REVERTANT COUNT IN PRE-INCUBATIONMETHOD (TRIAL II)

Dose (mg/plate)	In the presence of Metabolic Activation (+S9)
	TA 1537		TA 1535		TA 98		TA 100		TA 102
	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD
NC (0.00)	6.67	3.06	14.33	2.08	18.67	1.15	97.00	18.00	290.00	9.54
T1 (0.050)	5.33	1.53	13.67	2.31	18.33	2.52	96.67	3.51	289.67	6.11
T2 (0.158)	6.33	2.08	13.67	1.53	16.00	1.73	83.67	6.35	278.33	22.55
T3 (0.501)	7.33	2.08	14.00	3.46	17.67	2.08	93.33	6.35	285.33	4.51
T4 (1.582)	6.33	1.53	15.00	4.36	21.00	2.00	97.00	4.58	297.67	2.52
T5 (5)	7.00	1.00	16.67	0.58	17.67	2.08	90.67	7.51	272.67	8.74
PC	206.00	8.54	151.67	10.60	1052.00	68.20	1797.00	11.53	1859.00	66.09

 

 

 

Dose (mg/plate)	In the Absence of Metabolic Activation (-S9)
	TA 1537		TA 1535		TA 98		TA 100		TA 102
	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD	MEAN	SD
NC (0.00)	8.00	1.00	14.00	2.65	20.00	2.65	95.00	6.00	268.67	19.50
T1 (0.050)	7.00	2.00	14.00	3.61	18.00	2.65	95.33	8.08	255.67	14.36
T2 (0.158)	6.33	2.52	13.67	2.52	18.00	2.65	105.00	10.54	269.67	10.02
T3 (0.501)	6.67	3.06	13.00	2.00	17.67	3.79	93.00	3.46	290.00	9.54
T4 (1.582)	7.33	1.53	14.33	3.79	19.33	1.15	89.00	10.82	262.00	7.00
T5 (5)	7.00	2.65	12.33	1.53	17.00	3.61	98.67	1.15	277.33	6.66
PC	169.33	12.90	1455.00	123.08	846.33	87.85	1208.67	77.16	1938.67	81.71

NC= Negative Control,T =Test concentration (T5: Highest, T1: Lowest),SD= Standard Deviation

PC= Positive control

2-Aminoanthracene [2.5μg/plate]: TA 1537, TA 1535, TA 98, TA 100                  Methyl methanesulfonate [4μl/plate]: TA 102

2-Aminoanthracene [10μg/plate]:TA 102                                           

Sodium azide [10μg/plate]: TA 1535, TA 100

4-Nitro-o-phenylenediamine: TA 1537[50μg/plate], TA 98 [10μg/plate]

Conclusions:

Potassium hydrogen phthalate (CAS No. 877-24-7) did not induce gene mutations by base pair changes or frame shifts in the genome of the 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 it is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.

Executive summary:

Ames assay was performed to investigate the potential of Potassium hydrogen phthalate (CAS No. 877-24-7) to induce gene muta­tions in comparison to negative control according to the plate incorporation test (Trial I) and the pre-incubation test (Trial II) using theSalmonella typhimuriumstrains TA 1535, TA 1537, TA 98, TA 100 and TA 102.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the negative and positive controls was tested in triplicate. Based on the solubility and precipitation test results eight different concentrations viz., 0.0 (N.C), 0.002, 0.005, 0.016, 0.050, 0.158, 0.501, 1.582 and 5 mg/plate were selected for pre-experiment.

Based on the pre-experiment results, the test item was tested with the following concentrations: 0 (NC), 0.050, 0.158, 0.501, 1.582 and 5 mg/plate for main study, both in the presence of metabolic activation (+S9) and in the absence of metabolic activation (-S9).

No substantial increase in revertant colony numbers in any of the tester strains were observed following treatment with Potassium hydrogen phthalate (CAS No. 877-24-7) at any dose level in both the confirmatory trials, neither in the presence nor in the absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. The spontaneous reversion rates in the negative and positive controls were within the range of our historical data.

The positive controls used for various strains showed a distinct in­crease in induced revertant colonies in both the methods i.e. Plate incorporation method and Pre-incubation method.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item [Potassium hydrogen phthalate (CAS No. 877-24-7)] did not induce gene mutations by base pair changes or frame shifts in the genome of the strains used.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Gene mutation in vitro:

Ames test:

Ames assay was performed to investigate the potential of Potassium hydrogen phthalate (CAS No. 877-24-7) to induce gene muta­tions in comparison to negative control according to the plate incorporation test (Trial I) and the pre-incubation test (Trial II) using theSalmonella typhimuriumstrains TA 1535, TA 1537, TA 98, TA 100 and TA 102.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the negative and positive controls was tested in triplicate. Based on the solubility and precipitation test results eight different concentrations viz., 0.0 (N.C), 0.002, 0.005, 0.016, 0.050, 0.158, 0.501, 1.582 and 5 mg/plate were selected for pre-experiment.

Based on the pre-experiment results, the test item was tested with the following concentrations: 0 (NC), 0.050, 0.158, 0.501, 1.582 and 5 mg/plate for main study, both in the presence of metabolic activation (+S9) and in the absence of metabolic activation (-S9).

No substantial increase in revertant colony numbers in any of the tester strains were observed following treatment with Potassium hydrogen phthalate (CAS No. 877-24-7) at any dose level in both the confirmatory trials, neither in the presence nor in the absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. The spontaneous reversion rates in the negative and positive controls were within the range of our historical data.

The positive controls used for various strains showed a distinct in­crease in induced revertant colonies in both the methods i.e. Plate incorporation method and Pre-incubation method.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item [Potassium hydrogen phthalate (CAS No. 877-24-7)] did not induce gene mutations by base pair changes or frame shifts in the genome of the strains used.

Based on the experimental data available for the test chemical, Potassium hydrogen phthalate (CAS No. 877-24-7) does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.

Justification for classification or non-classification

Based on the experimental data available for the test chemical, Potassium hydrogen phthalate (CAS No. 877-24-7) does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.