(1-hydroxyethylidene)bisphosphonic acid, potassium salt

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

There are no in vitro data on genetic toxicity for HEDP-xK, therefore good quality data are read-across from the category member HEDP (2-3Na).

For bacterial mutagenicity, a weight of evidence approach has been used and includes the following studies:

In the in vitro gene mutation study in bacteria, conducted to a protocol similar to OECD Test Guideline 471 and pre-GLP, HEDP (2-3Na) has been tested for mutagenic potential in the Salmonella/microsomal assay in the presence and absence of metabolic activation using tester strains TA1535, TA1537, TA1538, TA98, and TA100. No increase in the number of revertants was detected with or without metabolic activation. It is concluded that the test substance is negative for mutagenicity under the conditions of the test (Microbiological Associates, Inc, 1976).

In the bacterial mutagenicity study (reliability score 1), conducted according to OECD Test Guideline 471 and in compliance with GLP, HEDP (2-3Na) was tested for inducing gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strain TA 102. It was concluded that HEDP (2-3Na) is non-mutagenic under the experimental conditions reported. The result has to be considered in combination with the earlier submitted bacterial reverse mutation assays and was conducted to provide information on the missing fifth strain (TA 102) (Harlan, 2015).

In the Ames test (reliability score 2), conducted prior to the adaptation of OECD Test Guidelines and pre-GLP, HEDP (2 -3Na) was tested for reverse mutation in the bacteria strains TA 98, 100, 1535, 1537 and 1538 with and without metabolic activation. No evidence for mutagenicity was obtained under the conditions of the study up to 2700 µg/plate. Appropriate controls were included and gave expected result. It was concluded that HEDP (2-3Na) is negative for gene mutation under the conditions of the test (Henkel, 1979).

In the key mammalian cell mutagenicity assay (reliability score 1), conducted according to OECD Test Guideline 476 and in compliance with GLP, HEDP (2-3 Na) was assessed for its induction of mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the presence and absence of metabolic activation. No reproducible, dose-dependent increase in the number of mutations was observed in either the initial or repeat experiment. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the conditions of the study (Harlan, 2010).

In the key in vitro human mammalian cell micronucleus test (reliability score 1), conducted according to OECD Test Guideline 487 and in compliance with GLP, HEDP (2-3Na) did not induce micronuclei under the experimental conditions reported. Therefore, it is concluded that the test substance is non-mutagenic when tested up to the highest required or evaluable concentrations (Envigo, 2015).

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

N/A to 1976-11-02

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

This study was conducted using methods comparable to OECD test guideline 471 (Bacterial Reverse Mutation Test) with the following deviations: (1) did not include a strain of bacteria to assess cross-linking mutagens; (2) concurrent strain-specific positive controls were not included for all bacterial strains used in the assay, both with metabolic activation (i.e., strains TA 1535 and TA 1537) and without metabolic activation (i.e., strains TA 1538 and TA 98); (3) the maximum recommended test concentration is 5 mg/plate and both 10 and 20 mg/plate were tested in this study; (4) only one set of negative control results were reported and it was not specified whether it was untreated or solvent negative control; (5) the study report did not include individual plate counts and the standard deviation for the mean number of revertant colonies per plate; (6) toxicity was not assessed in the main experiment.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Range of strains differs from current guideline; some positive controls not included, higher maximum recommended test concentration was used; toxicity was not assessed in the main experiment; did not include individual plate counts

GLP compliance:

no

Remarks:

pre-GLP

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine locus

Species / strain / cell type:

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

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

1, 2.5, 5, 10, and 20 mg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: No data
- Justification for choice of solvent/vehicle: N/A

Untreated negative controls:

yes

Remarks:

not clear in study report whether solvent or negative control was used

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: N-methyl-N-nitro-N-nitrosoguanidine- used for strains TA1535 and TA100 at .5 µg/plate

Remarks:

Without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Without metabolic activation: used for strain TA1537 at 100 µg/plate

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

With metabolic activation: Used for strains TA100, TA1538 and TA98 at 5 µg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)


DURATION
- Preincubation period: none
- Exposure duration: 48 hours
- Selection time (if incubation with a selection agent): 48 hours (simultaneous with exposure)
- Fixation time (start of exposure up to fixation or harvest of cells): N/A


SELECTION AGENT (mutation assays): Histidine deficient agar


NUMBER OF REPLICATIONS: 3


NUMBER OF CELLS EVALUATED: N/A


DETERMINATION OF CYTOTOXICITY
- Method: no data. It was summarized that a preliminary toxicity study was conducted on TA100 that established the use of 20 mg/plate as the high dose; however, in the study report it was stated that a preliminary toxicity test was not performed and that the test substance dose levels were selected arbitrarily after written instructions to test 20 mg/plate as the highest concentration.


OTHER EXAMINATIONS:
- Determination of polyploidy: N/A
- Determination of endoreplication: N/A
- Other: N/A


OTHER: N/A

Evaluation criteria:

For the test substance to be considered positive, it must have exhibited a dose response effect. For strains TA1535, TA1537, TA1538 and TA98, the first positive dose must have produced 2x the number of colonies as the negative control. For strain TA100, the highest positive dose must have produced 2.5x the number of mutants as the spontaneous reversion control. All positive observations must have been verified on a separate day. If initial test results couldn't be repeated, a positive result lost significance.

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

other: not valid with metabolic activation

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS

RANGE-FINDING/SCREENING STUDIES: Preliminary screening study was conducted on TA100. Based on the results of the preliminary toxicity study on TA100, 20 mg/plate was used as the high dose in the mutagenicity study


COMPARISON WITH HISTORICAL CONTROL DATA: All negative control values were within historical range.

ADDITIONAL INFORMATION ON CYTOTOXICITY: No evidence of cytotoxicity based on number of revertants per plate

Table 1a Plate incorporation assay. Number of revertants per plate (mean of 3 plates)

Concentration mg/plate	TA 1535		TA 100		TA 1537
	- MA	+ MA	- MA	+ MA	- MA	+ MA
0*	10	10	97	100	5	11
20	7	12	11	92	5	9
10	8	9	122	119	7	15
5	8	13	118	116	7	15
2.5	7	10	117	143	5	11
1.0	7	11	106	128	7	13
Positive control	1022	-	2197	478	1500	-

* Negative control - exact nature of this control not specified in study report

 

Table 1b Plate incorporation assay. Number of revertants per plate (mean of 3 plates)

Concentration mg/plate	TA 1538		TA 98
	- MA	+ MA	- MA	+ MA
0*	19	39	9	28
20	19	50	9	48
10	14	44	11	35
5	16	44	9	44
2.5	17	43	11	44
1.0	17	35	10	45
Positive control	-	78	-	214

* Negative control - exact nature of this control not specified in study report

The positive control for TA1538 in the presence of metabolic activation only produced 2x the number of colonies as the negative control, and therefore was not considered mutagenic based on it not producing the required 3x.

The test substance with TA98 in the presence and absence of metabolic activation gave uneven results at 10 mg: e.g., 75, 29, and 24 colonies per plate. The complete assay with TA98 was repeated.

Conclusions:

In an in vitro gene mutation study in bacteria, conducted to a protocol similar to OECD Test Guideline 471 and pre-GLP, HEDP (2-3Na) has been tested for mutagenic potential in the Salmonella/microsomal assay in the presence and absence of metabolic activation using tester strains TA1535, TA1537, TA1538, TA98, and TA100. No increase in the number of revertants was detected with or without metabolic activation. It is concluded that the test substance is negative for mutagenicity under the conditions of the test.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

Ames test, conducted prior to the adaptation of OECD Test Guidelines

Principles of method if other than guideline:

The test was performed according to Ames et al. (Mutation Research 31 (1975) 347-364), Methods for detecting carcinogens and mutagens wlth the salmonella/mammalian microsome mutagenicity test. Guideline was not available at the time the test was performed.

GLP compliance:

no

Remarks:

pre-GLP

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

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

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced and Phenbarbitol-induced rat liver S9

Test concentrations with justification for top dose:

Test substance: 2.7 / 27 / 270 / 2700 µg/plate
Positive controls: 67.5 µg/plate (o-nitro-p-phenylendiamin, 270 µg/plate (p-toluol-sulfonic acid hydrazide)
Solvent controls: 100 µl H2O + 100 µl acetone or 100 µl H2O + 100 µl DMSO, resp.
Untreated controls

Vehicle / solvent:

Water/acetone or water/DMSO, resp.

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water/acetone or water/DMSO, respectively

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: o-Nitro-p-phenylendiamine

Remarks:

Strains TA 1537, TA 1538, TA 98

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water/acetone or water/DMSO, respectively

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: p-toluolsulfonamidehydrazide

Remarks:

TA 100 and TA 1535

Evaluation criteria:

A substance is considered positive if at least one of the tested concentrations results in 2.5-times increase in the number of visible colonies relative to the solvent control in at least one test strains.

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Activity of Aroclor induced S9 was confirmed by testing TA 98 with Benzo-a-pyrene: 580 back mutations were induced. TA 100 induced 720 back mutations with 2-anthramine

Conclusions:

In an Ames test, conducted prior to the adaptation of OECD Test Guidelines and pre-GLP, HEDP (2-3Na) was tested for reverse mutation in the bacteria strains TA 98, 100, 1535, 1537 and 1538 with and without metabolic activation. No evidence for mutagenicity was obtained under the conditions of the study up to 2700 µg/plate. Appropriate controls were included and gave expected result. It was concluded that HEDP (2-3Na) is negative for gene mutation under the conditions of the test.

Reference 3

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix

Test concentrations with justification for top dose:

3; 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate

Vehicle / solvent:

Deionised water

Untreated negative controls:

yes

Remarks:

concurrent untreated control

Negative solvent / vehicle controls:

yes

Remarks:

deionised water

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: methylmethanesulfonate (without S9 Mix); 2-aminoanthracene (with S9 Mix)

Details on test system and experimental conditions:

Salmonella typhimurium; strain TA 102; genotype his G 428, rfa-, uvrB+, R-factor; type of mutations: base-pair substitutions.

DOSE SELECTION
Since the second experiment was performed, before the results of experiment I were available, both experiments were performed with the following concentrations: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate.
The maximum concentration was 5000 µg/plate. The concentration range covers at least two logarithmic decades. In this study at least five adequately spaced concentrations are tested.


EXPERIMENTAL PERFORMANCE
For each strain and dose level, including the controls, three plates were used. The following materials were mixed in a test tube and poured onto the selective agar plates:

Experiment I (Plate Incorporation)
100 µL Test solution at each dose level (solvent or reference mutagen solution (positive control)),
500 µL S9 mix (for test with metabolic activation) or S9 mix substitution buffer (for test without metabolic activation),
100 µL Bacteria suspension (cf. test system, pre-culture of the strains),
2000 µL Overlay agar

Experiment II (Pre-Incubation)
In the pre-incubation assay, 100 µL test solution (solvent or reference mutagen solution (positive controI)), 500 µL S9 mix / S9 mix substitution buffer and 100 µL bacterial suspension were mixed in a test tube and incubated at 37°C for 60 minutes. After pre-incubation 2.0 mL overlay agar (45°C) was added to each tube. The mixture was poured on minimal agar plates.
After solidification the plates were incubated upside down for at least 48 hours at 37°C in the dark.

Evaluation criteria:

A test substance is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice 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 and solvent controls such an increase is not considered biologically relevant.

The Salmonella typhimurium reverse mutation assay is considered acceptable if it meets the following criteria:
- regular background growth in the negative and solvent control
- the spontaneous reversion rates in the negative and solvent control are in the range of our historical data
- the positive control substances should produce a significant increase in mutant colony frequencies
- a minimum of five analysable dose levels should be present with at least three dose levels showing no signs of toxic effects, evident as a reduction in the number of revertants below the indication factor of 0.5.

Statistics:

The colonies were counted using the Petri Viewer Mk2 (Perceptive Instruments Ltd, Suffolk CB9 7BN, UK) with the software program Ames Study Manager (v.1.21). The counter was connected to a PC with printer to print out the individual values and mean values of the plates for each concentration together with standard deviations and enhancement factors as compared to the spontaneous reversion rates.

Key result

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

The test item HEDP-H neutralised to pH 7 was assessed for its potential to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella lyphimurium strain TA 102. The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration and the controls, were tested in triplicate.

The test item was tested at the following concentrations in both experiments: 3; 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate.

No precipitation of the test item occurred up to the highest investigated dose.

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without S9 mix.

No toxic effects, evident as a reduction in the number of revertants (below the indication factor of 0.5), occurred in the test groups with and without metabolic activation.

No substantial increase in revertant colony numbers was observed following treatment with SAT 140001 in strain TA 102 at any concentration level, neither in the presence nor 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.

Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies.

SUMMARY EXPERIMENT I

metabolic activation	test group	dose per plate [µg]	mean colony counts	SD
without	water (solvent control)	-	486	+/- 22
	untreated control	-	470	+/- 14
	test material	3	467	+/- 25
	test material	10	475	+/- 34
	test material	33	481	+/- 10
	test material	100	502	+/- 16
	test material	333	483	+/- 17
	test material	1000	491	+/- 15
	test material	2500	490	+/- 11
	test material	5000	525	+/- 7
	MMS (positive control)	2.0 µL	5235	+/- 450
with	water (solvent control)	-	625	+/- 12
	untreated control	-	625	+/- 10
	test material	3	615	+/- 15
	test material	10	631	+/- 14
	test material	33	640	+/- 32
	test material	100	663	+/- 13
	test material	333	587	+/- 32
	test material	1000	582	+/- 28
	test material	2500	571	+/- 12
	test material	5000	574	+/- 14
	2 -AA (positive control)	10.0 µg	1284	+/- 8

SUMMARY EXPERIMENT II

metabolic activation	test group	dose per plate [µg]	mean colony counts	SD
without	water (solvent control)	-	480	+/- 6
	untreated control	-	453	+/- 22
	test material	3	454	+/- 12
	test material	10	475	+/- 28
	test material	33	486	+/- 16
	test material	100	510	+/- 4
	test material	333	473	+/- 9
	test material	1000	492	+/- 12
	test material	2500	508	+/- 10
	test material	5000	501	+/- 24
	MMS (positive control)	2.0 µL	4983	+/- 269
with	water (solvent control)	-	620	+/- 8
	untreated control	-	642	+/- 39
	test material	3	643	+/- 21
	test material	10	664	+/- 27
	test material	33	660	+/- 30
	test material	100	697	+/- 36
	test material	333	628	+/- 26
	test material	1000	629	+/- 16
	test material	2500	616	+/- 42
	test material	5000	590	+/- 12
	2 -AA (positive control)	10.0 µg	1306	+/- 11

Conclusions:

In a bacterial mutagenicity study, conducted according to OECD Test Guideline 471 and in compliance with GLP (reliability score 1), HEDP (2-3Na) was tested for inducing gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strain TA 102. It was concluded that HEDP (2-3Na) is non-mutagenic under the experimental conditions reported. The result has to be considered in combination with the earlier submitted bacterial reverse mutation assays and was conducted to provide information on the missing fifth strain (TA 102).

Reference 4

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 12 2010 to June 28 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian cell gene mutation assay

Target gene:

Thymidine Kinase Locus

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media: RPMI
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
- Periodically "cleansed" against high spontaneous background: yes

Additional strain / cell type characteristics:

other: Clone 3.7.2C

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/Beta-Naphthoflavone induced Rat liver S9

Test concentrations with justification for top dose:

Experiment I, with and without S9 mix: 575, 1150, 2300, 4600, 9200, 18400 µg/ml (equivalent to 556-1784.8 µg/ml active acid);
Experiment II, without S9 mix: 287.5, 575, 1150, 2300, 3450, 4600 µg/ml (equivalent to 27.9-446 µg/ml active acid)
with S9 mix: 656.3, 1312.5, 2625, 5250, 10500, 21000 µg/ml (equivalent to 64-2067 µg/ml active acid).
without S9 mix: 21000 µg/mL (equivalent to 2067 µg/ml active acid).

Following the expression phase of 48 hours, the cultures at the lowest concentrations of 575 µg/ml in experiment I with and without metabolic activation were not continued since a minimum of only four analysable concentrations is required by the guidelines. In experiment II the concentrations at 287.5 µg/mL without metabolic activation and 656.3 µg/mL with metabolic activation were not continued for the same reason.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: deionised water
- Justification for choice of solvent/vehicle: solubility properties

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

deionised water

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

without metabolic activation

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

deionised water

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with metabolic activation

Details on test system and experimental conditions:

ACTIVATION: Phenobarbital/beta-naphthoflavone induced rat liver S9, NADP and glucose-6-phosphate as cofactors, final concentration in medium:5 % (v/v)

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: none
- Exposure duration: 4 hours with and without metabolic activation in experiment 1, 4 hours and 24 hours without metabolic activation in experiment and 4 hours with metabolic activation in experiment 2
- Expression time (cells in growth medium): 48 hours
- Selection time (if incubation with a selection agent): 10 to 15 days

SELECTION AGENT (mutation assays): RPMI 1640 medium by addition of 5 µg/ml TFT

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: >1,5 x 10 exp. 6 cells

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth


METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk

DURATION
- Preincubation period:
- Exposure duration: first experiment: 4 hours treatment with and without metabolic activation; second experiment: 24 hours treatment without metabolic activation, 4 hours treatment with metabolic activation
- Expression time (cells in growth medium): 48 h
- Selection time (if incubation with a selection agent): 10-15 days

SELECTION AGENT (mutation assays): TFT

NUMBER OF REPLICATIONS: duplicate cultures; negative result in first experiment confirmed in second experiment

DETERMINATION OF CYTOTOXICITY
- Method: relative suspension growth

OTHER EXAMINATIONS:
- Other: size distribution of colonies

Evaluation criteria:

A test item is classified as mutagenic if the induced mutation frequency reproducibly exceeds a threshold of 126 colonies per 10 exp. 6 cells above the corresponding solvent control or negative control, respectively.
A relevant increase of the mutation frequency should be dose-dependent.
A mutagenic response is considered to be reproducible if it occurs in both parallel cultures.
However, in the evaluation of the test results the historical variability of the mutation rates in negative and/or vehicle controls and the mutation rates of all negative and/or vehicle controls of this study are taken into consideration.
Results of test groups are generally rejected if the relative total growth and the cloning efficiency are less than 10 % of the vehicle control unless the exception criteria specified by the IWGT recommendations are fulfilled.
Whenever a test item is considered mutagenic according to the above mentioned criteria, the ratio of small versus large colonies is used to differentiate point mutations from clastogenic effects. If the increase of the mutation frequency is accompanied by a reproducible and dose dependent shift in the ratio of small versus large colonies clastogenic effects are indicated.

Statistics:

Linear regression analysis (least squares) using SYSTAT 11 (SYSTAT Software, Inc., 501, Canal Boulevard, Suite C, Richmond, CA 94804, USA)

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 3450.0 µg/ml (free acid), 24 h exposure

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: Not affected
- Effects of osmolality: Not increased
- Evaporation from medium: Not examined
- Water solubility: 12 %
- Precipitation: No precipitation was observed by the unaided eye up to the maximum concentration.
- Other confounding effects: None

RANGE-FINDING/SCREENING STUDIES:
The highest concentration level of a pure substance should be 10 mM (corresponding to 2.28 mg/ml of the active ingredient) unless limited by the toxicity of the test item (reduced cell culture growth and/or cloning efficiency). Thus the maximum concentration in the pre-experiment was 2.28 mg/ml of the active ingredient or 18.4 mg/mL of the test item as supplied based on a purity of 12.4%. Test item concentrations between 143.8 and 18400 µg/ml were used to evaluate toxicity in the presence (4 h treatment) and absence (4 h and 24 h treatment) of metabolic activation.
No relevant toxic effect occurred up to the maximum concentration tested with and without metabolic activation following 4 hours of treatment with and without metabolic activation. After 24 hours treatment strong toxic effects occurred at 4600 µg/mL and above.


COMPARISON WITH HISTORICAL CONTROL DATA: Performed


ADDITIONAL INFORMATION ON CYTOTOXICITY:
No relevant toxic effects indicated by a relative total growth of less than 50 % of survival in both parallel cultures were observed up to the maximum concentration with and without metabolic activation, following 4 hours of treatment. In experiment II following 24 hours treatment without metabolic activation, cytotoxic effects as described above occurred at 3450 and 4600 µg/mL. Based on the steep cytotoxic gradient of the test item the relative total growth (RTG) of both parallel cultures fell short of the lower limit of approximately 10%. However, according to the current IWGT recommendations data at RTG levels between 1 and 10% can be used to support a non mutagenic result provided that the dose spacing was 2.0 or lower and no relevant increase of the mutation frequency is observed at RTG levels below 10%.

Summary Table

conditions	conc. µg/ml (aqueous salt solution	conc. µg/ml (free acid)	S9 mix	relative total growth	mutant colonies/ 10^6cells	threshold	relative total growth	mutant colonies/ 10^6cells	threshold
Experiment I / 4 h treatment				culture I			culture II
Solv. control with water			-	100.0	113	239	100.0	95	221
Pos. control with MMS	19.5		-	30.6	309	239	33.0	299	221
Test item	575.0	72.1	-	culture was not continued^#			culture was not continued^#
Test item	1150.0	144.1	-	71.7	254	239	156.4	115	221
Test item	2300.0	288.3	-	70.2	168	239	110.0	177	221
Test item	4600.0	576.6	-	61.0	226	239	136.8	149	221
Test item	9200.0	1153.2	-	86.3	165	239	98.2	131	221
Test item	18400.0	2306.3	-	74.3	184	239	85.6	170	221
Experiment I / 4 h treatment				culture I			culture II
Solv. control with water			+	100.0	165	291	100.0	139	265
Pos. control with CPA	3.0		+	79.1	340	291	49.5	144	265
Pos. control with CPA	4.5		+	30.7	311	291	23.4	344	265
Test item	575.0	72.1	+	culture was not continued^#			culture was not continued^#
Test item	1150.0	144.1	+	143.5	174	291	83.9	183	265
Test item	2300.0	288.3	+	102.5	179	291	88.1	92	265
Test item	4600.0	576.6	+	120.4	131	291	80.7	107	265
Test item	9200.0	1153.2	+	91.5	129	291	83.7	162	265
Test item	18400.0	2306.3	+	76.7	149	291	61.7	128	265
Experiment II / 24 h treatment				culture I			culture II
Solv. control with water			-	100.0	189	315	100.0	124	250
Pos. control with MMS	13.0		-	17.9	630	315	12.4	489	250
Test item	287.5	36.0	-	culture was not continued^#			culture was not continued^#
Test item	575.0	72.1	-	60.7	178	315	86.8	165	250
Test item	1150.0	144.1	-	66.5	149	315	94.9	170	250
Test item	2300.0	288.3	-	70.8	144	315	82.9	155	250
Test item		432.4	-	37.0	134	315	32.1	119	250
Test item	4600.0	576.6	-	5.6	102	315	2.8	211	250
Experiment II / 4 h treatment				culture I			culture II
Solv. control with water			+	100.0	173	299	100.0	141	267
Pos. control with CPA	3.0		+	45.7	332	299	35.8	497	267
Pos. control with CPA	4.5		+	51.7	357	299	50.1	427	267
Test item	656.3	82.3	+	culture was not continued^#			culture was not continued^#
Test item	1312.5	164.5	+	91.4	178	299	98.8	154	267
Test item	2625.0	329.0	+	82.9	194	299	74.4	163	267
Test item	5250.0	658.1	+	89.4	191	299	73.1	178	267
Test item	10500.0	1316.1	+	93.9	169	299	79.0	183	267
Test item	21000.0	2632.0	+	96.3	183	299	71.9	204	267
Experiment II / 4 h treatment				culture I			culture II
Solv. control with water			-	100.0	159	285	100.0	169	295
Pos. control with MMS	19.5		-	16.1	601	285	17.8	639	295
Test item	21000.0	2632.0	-	74.0	203	285	51.6	298	295

threshold = number of mutant colonies per 10⁶cells of each solvent control plus 126

#  culture was not continued since a minimum of four concentrations is required by the guidelines

 

Conclusions:

In a mammalian cell mutagenicity assay (reliability score 1), conducted according to OECD Test Guideline 476 and in compliance with GLP, HEDP (2-3Na) (neutral pH) was assessed for its induction of mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the presence and absence of metabolic activation. No reproducible, dose-dependent increase in the number of mutations was observed in either the initial or repeat experiment. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the conditions of the study.

Reference 5

Endpoint:

in vitro cytogenicity / micronucleus study

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not specified

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

other: OECD 487 (in vitro Mammalian Cell Micronucleus Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian cell micronucleus test

Species / strain / cell type:

lymphocytes: human

Metabolic activation:

with and without

Metabolic activation system:

rat liver S9 mix

Test concentrations with justification for top dose:

EXPERIMENT I
- without S9 mix: 13.7, 24.1, 42.1, 73.7, 128.9, 225.7, 394.9, 691.1, 1209.4, 2116.4 µg/mL
- with S9 mix: 13.7, 24.1, 42.1, 73.7, 128.9, 225.7, 394.9, 691.1, 1209.4, 2116.4 µg/mL

EXPERIMENT II
- without S9 mix: 13.7, 24.1, 42.1, 73.7, 128.9, 225.7, 394.9, 691.1, 1209.4, 2116.4 µg/mL

Vehicle / solvent:

Deionised water

Untreated negative controls:

other: solvent control served as negative control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

without S9 - pulse treatment

Untreated negative controls:

other: solvent control served as negative control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: demecolcin

Remarks:

without S9 - continuous treatment

Untreated negative controls:

other: solvent control served as negative control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with S9

Details on test system and experimental conditions:

HUMAN LYMPHOCYTES
Blood samples were drawn from healthy non-smoking donors not receiving medication. For this study, blood was collected from a male donor (29 years old) for Experiment I and from a male donor (31 years old) for Experiment II. The lymphocytes of the respective donors have been shown to respond well to stimulation of proliferation with PHA and to positive control substances. All donors had a previously established low incidence of micronuclei in their peripheral blood lymphocytes.
Human lymphocytes were stimulated for proliferation by the addition of the mitogen PHA to the culture medium for a period of 48 hours. The cell harvest time point was approximately 2 – 2.5 x AGT (average generation time). Any specific cell cycle time delay induced by the test item was not accounted for directly.

CULTURE CONDITIONS
Blood cultures were established by preparing an 11 % mixture of whole blood in medium within 30 hrs after blood collection. The culture medium was Dulbecco's Modified Eagles Medium/Ham's F12 (DMEM/F12, mixture 1:1) already supplemented with 200 mM GlutaMAX™. Additionally, the medium was supplemented with penicillin/streptomycin (100 U/mL/100 μg/mL), the mitogen PHA (3 μg/mL), 10 % FBS (fetal bovine serum), 10 mM HEPES and the anticoagulant heparin (125 U.S.P.-U/mL). All incubations were done at 37 °C with 5.5 % CO2 in humidified air.

Evaluation criteria:

Evaluation of the slides was performed using NIKON microscopes with 40 x objectives. The micronuclei were counted in cells showing a clearly visible cytoplasm area. The criteria for the evaluation of micronuclei are described in the publication of Countryman and Heddle. The micronuclei have to be stained in the same way as the main nucleus. The area of the micronucleus should not extend the third part of the area of the main nucleus. At least 1000 binucleate cells per culturewere scored for cytogenetic damage on coded slides. The frequency of micronucleated cells was reported as % micronucleated cells. To describe a cytotoxic effect the CBPI is determined in approximately 500 cells per culture and cytotoxicity is described as % cytostasis. A CBPI of 1 (all cells are mononucleate) is equivalent to 100 % cytostasis.

CBPI=(MONCx1)+(BINCx2)+(MUNCx3)/n

CBPI Cytokinesis-block proliferation index
n Total number of cells
MONC Mononucleate cells
BINC Binucleate cells
MUNC Multinucleate cells

Cytostasis % = 100 – 100 [(CBPIT – 1) / (CBPIC – 1)]

T Test item
C Solvent control

Statistics:

Statistical significance will be confirmed by using the Chi-squared test (α < 0.05) using the validated R Script CHI2.Rnw for those values that indicate an increase in the number of cells with micronuclei compared to the concurrent solvent control.

Key result

Species / strain:

lymphocytes: human

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

In both experiments, no precipitation of the test item in the culture medium was observed.

No relevant influence on osmolarity was observed. The pH was adjusted to physiological values.

In Experiment I in the absence and presence of S9 mix and in Experiment II in the absence of S9 mix, no cytotoxicity was observed up to the highest applied concentration.

No relevant increase in micronucleated cells was observed after treatment with the test item. However, in Experiment I in the presence of S9 mix, at a concentration of 691.1 μg/mL a statistically significant increase in the number of micronucleated cells (0.75 %) was observed after treatment with the test item. The value lies within the range of the laboratory historical control data (0.15 – 1.70 % micronucleated cells) and can be estimated as biologically irrelevant.

In both experiments, either Demecolcin (100.0 ng/mL), MMC (2.0 μg/mL) or CPA (17.5 μg/mL) were used as positive controls and showed distinct increases in cells with micronuclei.

Experiment	Exposure	Conc. [µg/mL]	CBPI	Cytostasis [%]	Micronucleated cells [%]
I	4 h -S9	SC	1.88		0.30
I	4 h -S9	PC	1.14	84.7	10.30
I	4 h -S9	691.1	1.67	24.4	0.10
I	4 h -S9	1209.4	1.79	10.0	0.50
I	4 h -S9	2116.4	1.75	14.7	0.35
II	20 h -S9	SC	1.51		1.35
II	20 h -S9	PC	1.44	12.5	5.45
II	20 h -S9	394.9	1.79	nc	0.55
II	20 h -S9	691.1	1.60	nc	0.60
II	20 h -S9	1209.4	1.53	nc	0.20
I	4 h +S9	SC	1.92		0.30
I	4 h +S9	PC	1.46	50.3	4.85
I	4 h +S9	691.1	1.95	nc	0.75
I	4 h +S9	1209.4	1.91	1.2	0.70
I	4 h +S9	2116.4	1.91	0.7	0.30

SC = Solvent control

PC = Positive control

CBPI = Proliferation index

nc = not calculated (CBPI equal or higher than solvent control value)

Conclusions:

In an in vitro human mammalian cell micronucleus test, conducted according to OECD Test Guideline 487 and in compliance with GLP, HEDP (2-3Na) did not induce micronuclei under the experimental conditions reported. Therefore, it is concluded that the test substance is non-mutagenic when tested up to the highest required or evaluable concentrations.

Executive summary:

The test item SAT 140001, dissolved in deionised water, was assessed for its potential to induce micronuclei in human lymphocytes in vitro in two independent experiments. The following study design was performed:

	Without S9		With S9
	Exp. I	Exp. II	Exp. I
Stimulation period	48 h	48 h	48 h
Exposure period	4 h	20 h	4 h
Recovery	16 h	-	16 h
Cytochalasin B exposure	20 h	20 h	20 h
Total culture period	88 h	88 h	88 h

In each experimental group two parallel cultures were analysed. Per culture 1000 binucleated cells were evaluated for cytogenetic damage.

The highest applied concentration in this study (2116.4 μg/mL of the test item) was chosen with regard to the purity (94.5%) of the test item and with respect to the current OECD Guideline 487. Dose selection of the cytogenetic experiment was performed considering the toxicity data in accordance with OECD Guideline 487.

In Experiment I in the absence and presence of S9 mix and in Experiment II in the absence of S9 mix, no cytotoxicity was observed up to the highest applied concentration.

No relevant increase in micronucleated cells was observed after treatment with the test item. However, in Experiment I in the presence of S9 mix, at a concentration of 691.1 μg/mL a statistically significant increase in the number of micronucleated cells (0.75 %) was observed after treatment with the test item. The value lies within the range of the laboratory historical control data (0.15 – 1.70 % micronucleated cells) and can be estimated as biologically irrelevant.

Appropriate mutagens were used as positive controls. They induced statistically significant increases in cells with micronuclei.

In conclusion, it can be stated that under the experimental conditions reported, the test item did not induce micronuclei as determined by the in vitro micronucleus test in human lymphocytes. Therefore, HEDP (2 -3Na) is considered to be non-mutagenic in this in vitro micronucleus test, when tested up to the highest required or evaluable concentrations.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

There are no in vivo data on genetic toxicity for HEDP-xK, therefore good quality data are read-across from the category member HEDP (2-3Na).

In the key in vivo mouse micronucleus assay (reliability score 2), conducted to a protocol similar to OECD Test Guideline 474 and pre-GLP, HEDP (2-3Na) did not cause any increase in the number of PCEs detected after intraperitoneal administration. Appropriate controls were included and gave expected result. It is concluded that HEDP (2-3Na) is negative for induction of micronuclei under the conditions of the test (Henkel, 1979).

In the key in vivo dominant lethal assay (reliability score 2), conducted to a protocol similar to OECD Test Guideline 478 and pre-GLP, HEDP (2-3Na) was tested using male mice that were orally dosed once daily for five days. No test substance-related variations relative to control values in conception rates, total implant averages, foetal death averages, resorption percentage or mutagenic indices were observed. It was concluded that HEDP (2-3Na) is non-mutagenic under the conditions of the study (P&G, 1974).

Link to relevant study records

Reference

Reference 1

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

only 4 animals per sex per dose; only one sample of bone marrow; only 2 doses

Principles of method if other than guideline:

Method: Schmid W, Mutation Res, 31, (1975), 9-15.

GLP compliance:

no

Remarks:

pre-GLP

Type of assay:

micronucleus assay

Species:

mouse

Strain:

CF-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 weeks

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: No data

Duration of treatment / exposure:

Two intraperitoneal doses at 0 and 24 hours

Dose / conc.:

18.75 mg/kg bw/day (nominal)

Dose / conc.:

150 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

four

Control animals:

yes, concurrent no treatment

Positive control(s):

- Endoxan
- Doses / concentrations: 120 mg/kg bw

Tissues and cell types examined:

Femoral bone marrow

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Table 1: Mean Results of in vivo micronucleus test with mouse bone marrow

-	Negative Control	Negative Control	Positive Control (Endoxan)	Positive Control (Endoxan)	Low dose 18.75 mg/kg	Low dose 18.75 mg/kg	High dose 150 mg/kg	High dose 150 mg/kg
	male	female	male	female	male	female	male	female
Sampling time (h)	6	6	6	6	6	6	6	6
Number of cells analysed	1000	1000	1000	1000	1000	1000	1000	1000
Micronucleated cells per animal %	3	3.3	35	34	3	2.8	3.3	1.5
Ratio PCE/NCE	782	815	250	386	785	852	875	947

Conclusions:

In an in vivo mouse micronucleus assay, conducted to a protocol similar to OECD Test Guideline 474 and pre-GLP, HEDP (2-3Na) did not cause any increase in the number of PCEs detected after ip administration. Appropriate controls were included and gave expected result. It is concluded that HEDP (2-3Na) is negative for induction of micronuclei under the conditions of the test.

Reference 2

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1974-02-04 to 1974-09-10

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Rodent Dominant Lethal Test. A postive control substance was not included in this study.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 478 (Genetic Toxicology: Rodent Dominant Lethal Test)

Deviations:

yes

Remarks:

Postive control substance was not included in this study.

Principles of method if other than guideline:

N/A

GLP compliance:

no

Remarks:

pre-GLP

Type of assay:

rodent dominant lethal assay

Species:

mouse

Strain:

other: C3D2F1/J

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Jackson Laboratories, Bar Harbor, Maine
- Age at study initiation: Sexually mature
- Weight at study initiation: N/A
- Assigned to test groups randomly: Yes, on the basis of body weight
- Fasting period before study: N/A
- Housing: N/A
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: One week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): N/A
- Humidity (%): N/A
- Air changes (per hr): N/A
- Photoperiod (hrs dark / hrs light): N/A


IN-LIFE DATES: From: N/A To: N/A

Immediately following treatment, each male was caged with two untreated females for a period of seven days, and with two fresh females the following week. This procedure was continued for a total of six weeks, thereby encompassing the entire spermatogenic cycle of the mouse, which was purported to be 35 days.
Consequently, each male was mated to twelve females over a six-week period: A total of 240 matings per dose group.
On day 13 or 14 of gestation (as measured from the mid-week of presumptive mating), the females were sacrificed. Total implants, resorptions and dead embryos were enumerated and recorded.
Various parameters such as average number of implants per female, average number of fetal deaths/female, fetal deaths per sire, and percent pregnancy per group were subjected to statistical analysis.

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: Water
- Justification for choice of solvent/vehicle: N/A
- Concentration of test material in vehicle: N/A
- Amount of vehicle: 0.25 mL
- Type and concentration of dispersant aid: N/A
- Lot/batch no.: N/A
- Purity: N/A

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: N/A

DIET PREPARATION
- Rate of preparation of diet: N/A
- Mixing appropriate amounts with: N/A
- Storage temperature of food: N/A

OTHER: Each of three groups of mice received the test substance (as a single oral daily dose in 0.25 mL volumes), at levels of 20, 200 or 1000 mg/kg bw for five days. One other group received water for five days. The fifth group received no treatment.

Duration of treatment / exposure:

5 days

Frequency of treatment:

once daily

Post exposure period:

N/A

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Remarks:

Control group, no treatment

Dose / conc.:

20 mg/kg bw/day (actual dose received)

Dose / conc.:

200 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

20

Control animals:

yes, concurrent no treatment

yes, concurrent vehicle

Positive control(s):

Positive controls: None

Tissues and cell types examined:

total implants, resorptions and dead embryos

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: The top dose for the dominant lethal assay was based on the maximum tolerated dose determined from a preliminary study (see below under additional information on results). The intermediate dosing level was arbitrarily set at 200 mg/kg bw and the lower test group received the human-usage level of 20 mg/kg bw.

TREATMENT AND SAMPLING TIMES: N/A

DETAILS OF SLIDE PREPARATION: N/A

METHOD OF ANALYSIS: N/A

OTHER: N/A

Evaluation criteria:

N/A

Statistics:

Data from experimental groups were compared to data from control groups using the Chi-square test for significant deviations (P<= 0.05, DF=1)

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

not applicable

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 62.5-2000 mg/kg bw
- Solubility: N/A
- Clinical signs of toxicity in test animals: 2 out of 10 mice died at the 2000 mg/kg dose level.
- Evidence of cytotoxicity in tissue analysed: N/A
- Rationale for exposure: To determine an LD50 and/or a maximum tolerated dose for mice.
- Harvest times: Animals were exposed daily for 5 consecutive days.
- High dose with and without activation: 2000 mg/kg without activation
- Other: An LD50 could not be calculated, but the maximum tolerated dose was chosen as 1000 mg/kg.


RESULTS OF DEFINITIVE STUDY
- Appropriateness of dose levels and route: Top dose was based on maximum tolerated dose.
- Statistical evaluation: N/A

Total litter losses occurred very rarely throughout the study and showed no dose response to the test substance. Only two litters approached being totally lost in all test groups. One incident occurred in the untreated controls in which two to three implants in one female were dead and another occurred in the high dose group in which only one of five implants was alive at necropsy. Both litter losses originated during the third week of mating and were attributed to a malfunction in the individual animals and therefore were not considered test-substance related. The number of deaths in females mated with males given the test substance did not differ significantly from those in concurrent controls for any of the mating periods. Mating performance of all test groups compared favorably with the controls. As in the examination of individual female data, individual poor performance of the sire which was not test related could easily be detected. For example one male in the mid test group failed to impregnate a female until the fifth week of mating. In the final two weeks of the study, three of the four females mated with this male mouse conceived but only carried an average of six implants per pregnancy. The average number of implants for the rest of the group was 8.9 for the entire study and 9.0 for all other sires combined during the same two weeks of mating. The fact that eighteen implants sired by the male mouse mentioned above produced no fetal deaths provides additional evidence supporting the decision that the performance of this male was not test related. When it came to conception rates, implants and fetal mortality, little variation occurred between test groups and controls for any of the parameters measured. The mutagenic index was measured. It was a calculation based on two independent variables, fetal deaths and total implants, used as a convenient comparison of group to group performance. No significant differences (P= 0.05. D.F=1) were found when test group mutagenic indices were compared to either the vehicle or untreated controls.

Conclusions:

In an in vivo dominant lethal assay, conducted to a protocol similar to OECD Test Guideline 478 and pre-GLP, HEDP (2-3Na) was tested using male mice that were orally dosed once daily for five days. No test substance-related variations relative to control values in conception rates, total implant averages, foetal death averages, resorption percentage or mutagenic indices were observed. It was concluded that HEDP (2-3Na) is non-mutagenic non-mutagenic under the conditions of the study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

A weight of evidence approach for bacterial mutagenicity has been used and include the following studies:

In an in vitro gene mutation study in bacteria (reliability score 2), conducted to a protocol similar to OECD Test Guideline 471 and pre-GLP, HEDP (2-3Na) has been tested for mutagenic potential in the Salmonella/microsomal assay in the presence and absence of metabolic activation using tester strains TA1535, TA1537, TA1538, TA98, and TA100. Cultures were treated for 48 hours using the plate incorporation method at dose levels ranging from 1.0 -20 mg/plate. Negative controls were included for all strains, while positive controls were included for TA1535, TA100 and TA1537 in the absence of metabolic activation and for TA100, TA1538 and TA98 in the presence of metabolic activation.

All negative control values were within historical range. The positive control for TA1538 in the presence of metabolic activation did not induce a mutagenic response. No increase in the number of revertants was detected with or without metabolic activation. It is concluded that the test substance is negative for mutagenicity under the conditions of the test (Microbiological Associates, Inc, 1976).

 

In the bacterial mutagenicity study (reliability score 1), conducted according to OECD Test Guideline 471 and in compliance with GLP, HEDP (2-3Na) was tested for inducing gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strain TA 102. Each concentration, including the controls, was tested in triplicate and included the concentrations 3, 10, 33, 100, 333, 1000, 2500 or 5000 µg/plate. No precipitation of the test item occurred up to the highest investigated dose. No substantial increase in revertant colony numbers was observed following treatment with HEDP (2-3Na) occurred at any dose level, neither in the presence nor the absence of metabolic activation. It was concluded that HEDP (2-3Na) is non-mutagenic under the experimental conditions reported. The result has to be considered in combination with the earlier submitted bacterial reverse mutation assays and was conducted to provide information on the fifth missing strain (TA 102) (Harlan, 2015).

 

In an Ames test (reliability score 2), conducted prior to the adaptation of OECD Test Guidelines and pre-GLP, HEDP (2 -3Na) was tested for reverse mutation in the bacteria strains TA 98, 100, 1535, 1537 and 1538 with and without metabolic activation. No evidence for mutagenicity was obtained under the conditions of the study up to 2700 µg/plate. Appropriate controls were included and gave expected result. It was concluded that HEDP-3Na is negative for gene mutation under the conditions of the test (Henkel, 1979).

 

In the key mammalian cell mutagenicity assay (reliability score 1), conducted according to OECD Test Guideline 476 and in compliance with GLP, HEDP (2 -3Na) was assessed for its induction of mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the presence and absence of metabolic activation in two independent experiments. No reproducible, dose-dependent increase in the number of mutations was observed in either the initial or repeat experiment. Appropriate controls were used and gave expected results. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the conditions of the study (Harlan, 2010).

 

In the key in vitro human mammalian cell micronucleus test (reliability score 1), conducted according to OECD Test Guideline 487 and in compliance with GLP, HEDP (2-3Na) was dissolved in deionised water and assessed for its potential to induce micronuclei in human lymphocytes in vitro in two independent experiments. No relevant increase in micronucleated cells was observed after treatment with the test substance. However, in Experiment I in the presence of S9 mix, at a concentration of 691.1 μg/mL, a statistically significant increase in the number of micronucleated cells (0.75 %) was observed. However, the value was within the range of the laboratory historical control data (0.15 – 1.70 % micronucleated cells) and can therefore be considered as a not treatment-related effect. In Experiment I in the absence and presence of S9 mix and in Experiment II in the absence of S9 mix, no cytotoxicity was observed up to the highest applied concentration. Appropriate positive and vehicle controls were included and provided expected result. In conclusion, HEDP (2-3Na) is considered to be non-mutagenic when tested under the conditions of the test (Envigo, 2015).

 

In the key in vivo mouse micronucleus assay (reliability score 2), conducted to a protocol similar to OECD Test Guideline 474 and pre-GLP, HEDP (2-3Na) did not cause any increase in the number of PCEs detected after intraperitoneal administration. Appropriate controls were included and gave expected result. It is concluded that HEDP (2 -3Na) is negative for induction of micronuclei under the conditions of the test (Henkel, 1979).

 

In the key in vivo dominant lethal assay, conducted to a protocol similar to OECD Test Guideline 478 and pre-GLP (reliability score 2), HEDP (2 -3Na) was tested using male mice that were orally dosed once daily in concentrations of 20, 200 or 1000 mg/kg bw for five consecutive days. Each male was mated to twelve females over a six-week period resulting in a total of 240 matings per dose group. On day 13 or 14 of gestation (as measured from the mid-week of presumptive mating), the females were sacrificed. Total implants, resorptions and dead embryos were enumerated and recorded. No significant test substance-related variations relative to control values occurred in conception rates, average of total implant, average of foetal death, resorption percentage or mutagenic indices. It was concluded that HEDP (2 -3Na) is non-mutagenic under the conditions of the study (P&G, 1974).

See read-across justification in IUCLID Section 13.

Justification for classification or non-classification

Based on the available read-across in vitro and in vivo genotoxicity data no classification for mutagenicity is required for HEDP-xK according to Regulation (EC) No 1272/2008.