Reaction mass of glycerol, glycerol 1-formate, glycerol 2-formate, glycerol 1,2-diformate, glycerol 1,3-diformate and glycerol triformate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

It is reasonable to expect that the target substance will also not cause mutagenic effects in bacterial systems.

It is reasonable to expect that the target substance would also be without clastogenic activity.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

This endpoint study record is part of a Weight of Evidence approach comprising of read-across from three analogue source substance studies. The results of the read-across studies agree as to the potential for cytogenicity in mammalian cells and are sufficient to fulfil the information requirements as further explained in the provided genetic toxicity endpoint summary.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Data for propane-1,2,3-triol (glycerol; CAS No. 56-81-5), formic acid, sodium salt (1:1) (sodium formate; CAS No. 141-53-7), formic acid, potassium salt (1:1) (potassium formate; CAS No. 590-29-4), formic acid, potassium salt (2:1) (potassium diformate; CAS No. 20642-05-1), formic acid, calcium salt (2:1) (calcium formate; CAS No. 544-17-2), 1,2-ethanediol, 1,2-diformate (ethylene diformate; CAS No. 629-15-2), 1,2-ethanediol (ethylene glycol; CAS No. 107-21-1) and formic acid (CAS No. 64-18-6) is used to address the toxicological data requirements for propane-1,2,3-triol and its esterification products with formic acid (EC No. 701-316-8) in an analogue read-across approach. The basis for this read-across approach is that, upon oral administration, the target substance is expected to undergo stepwise transformation by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to free glycerol, with formic acid being released at each step, as illustrated in Figure 1. The toxicity of the glycerol constituent/metabolite will be assessed using information on glycerol, and the toxicity of the formic acid metabolite will be assessed using information on sodium formate, potassium formate, potassium diformate, calcium formate, ethylene diformate, ethylene glycol and formic acid.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Target Substance: Propane-1,2,3-triol and its esterification products with formic acid; 701-316-8
Source Substance 1: Propane-1,2,3-triol ; 200-289-5 ; 56-81-5
Source Substance 2: Formic acid, sodium salt (1:1) ; 205-48-0 ; 141-53-7
Source Substance 3: Formic acid, potassium salt (1:1) ; 209-677-9 ; 590-29-4
Source Substance 4: Formic acid, potassium salt (2:1) ; 243-934-6 ; 20642-05-1
Source Substance 5: Formic acid, calcium salt (2:1) ; 208-863-7 ; 544-17-2
Source Substance 6: 1,2-Ethanediol, 1,2-diformate ; 211-077-7 ; 629-15-2
Source Substance 7: 1,2-Ethanediol ; 203-473-3 ; 107-21-1
Source Substance 8: Formic acid ; 200-579-1 ; 64-18-6
[See attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details.]

The TS is a UVCB substance of 100% purity. On this basis, the source substances collectively represent 100% w/w of the target substance. The purities of the samples of source substances that were tested are not specifically known, but it is assumed that they would not have been sufficiently impure as to substantially affect the study results. On this basis, the applicability of the data on the source substances to the TS is not expected to be compromised by the presence of impurities in any of the substances.

3. ANALOGUE APPROACH JUSTIFICATION
The basis for this read-across approach is that, upon oral administration, the TS is expected to undergo stepwise hydrolysis by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to the free glycerol constituent, with formic acid being released at each step.
The TS is manufactured from a 1:1 molar ratio of glycerol and formic acid reactants and will therefore metabolize back to those same proportions of those same reactants. An exposure of an organism to the TS is therefore considered to be essentially equivalent to an exposure to a 1:1 molar mixture of glycerol and formic acid.

Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details as to how the source substances relate to the target substance.

For the following toxicity endpoints:
8.2 serious eye damage / eye irritation
8.3 skin sensitisation
8.5.1 acute toxicity by oral route
8.4.1 in vitro gene mutation study in bacteria;
8.4.2 mutagenicity: in vitro cytogenicity study in mammalian cells;
8.4 mutagenicity: in vivo genotoxicity;
8.6.3 long-term repeated dose toxicity: ≥ 12 months; and
8.7.2 developmental toxicity
information on the glycerol constituent/metabolite and the formic acid metabolite of the target substance will be used to predict the properties of the target substance.

4. DATA MATRIX
Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for data matrix details.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Species / strain:

other: Weight of evidence based on Chinese hamster lung fibroblasts, Chinese Hamster Ovary, and human peripheral blood lymphocytes

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Conclusions:

Given that the analogue source substances have been shown to be without clastogenic activity, it is reasonable to expect that the target substance would also be without clastogenic activity.

Executive summary:

An in vitro test for chromosome aberrations on the analogue source substance propane-1,2,3-triol has been reported (Ishidate, et al., 1984). Treatment of Chinese hamster lung fibroblasts with propane-1,2,3-triol at doses of up to 1.0 mg/mL for a period of either 24- or 48-hours was reported to not increase the frequencies of chromosome aberrations. In the 48-hour exposure experiment, the incidence of structural aberrations and polyploidy was 1.0 and 2.0%, respectively. The authors concluded that the analogue source substance propane-1,2,3-triol was not genotoxic in the in vitro mammalian chromosome aberration assay.

The in vitro chromosome aberration assay using Chinese Hamster Ovary (CHO) cells was conducted with analogue source substance formic acid at concentrations of up to 6-14 mM (270-630 μg/mL) (Morita, et al., 1990). Cytotoxicity was observed when pH was below 6 (equivalent to 12-14 mM). The concentration of 30 mM formic acid was cytotoxic even when neutralized. Chromosomal aberrations were observed at an initial pH of 6.0 or 6.2 (10-12 mM) in the presence and absence of S9-mix. However, when the medium was buffered with sodium hydroxide to provide a pH of 7.2, concentration of up to 20 or 25 mM did not induce clastogenic effects. In contrast, increased numbers of aberrations were observed at 27.5 mM of sodium bicarbonate or at 25 mM neutralized with HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid). The study authors noted that observed clastogenic effects were associated with acidic conditions. The study authors concluded that the clastogenicity and cytotoxicity were associated with pH-effects, whereas formic acid itself, and consequently the sodium formate produced during neutralization, did not induce chromosomal aberrations.

Additional information on the chromosomal aberration potential of the analogue source substance formic acid, potassium salt (2:1) was reviewed as a part of the OECD SIDS Initial Assessment Report for formic acid and formats (OECD SIDS, 2008). The assessment report noted that formic acid, potassium salt (2:1) was negative for chromosomal aberrations when tested in an in vitro assay using human peripheral blood lymphocytes performed in accordance with OECD Test Guideline 473. In this study, human peripheral blood lymphocytes obtained from two non-smoking volunteers were exposed to concentrations of up to 1301 μg/mL for 3, 20, and 44 hours without metabolic activation and 2 and 3 hours with metabolic activation. Cells were harvested at 20 and 44 hours after the treatment was started. The positive controls produced the expected results, thus validating the experimental protocol. The study authors concluded that formic acid, potassium salt (2:1) was negative for inducing structural or numerical aberrations in human peripheral blood lymphocytes.

Given that the analogue source substances have been shown to be without clastogenic activity, it is reasonable to expect that the target substance would also be without clastogenic activity.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

This endpoint study record is part of a Weight of Evidence approach comprising of read-across from three analogue source substance studies. The results of the read-across studies agree as to the potential for gene mutation in bacteria and are sufficient to fulfil the information requirements as further explained in the provided genetic toxicity endpoint summary.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Data for propane-1,2,3-triol (glycerol; CAS No. 56-81-5), formic acid, sodium salt (1:1) (sodium formate; CAS No. 141-53-7), formic acid, potassium salt (1:1) (potassium formate; CAS No. 590-29-4), formic acid, potassium salt (2:1) (potassium diformate; CAS No. 20642-05-1), formic acid, calcium salt (2:1) (calcium formate; CAS No. 544-17-2), 1,2-ethanediol, 1,2-diformate (ethylene diformate; CAS No. 629-15-2), 1,2-ethanediol (ethylene glycol; CAS No. 107-21-1) and formic acid (CAS No. 64-18-6) is used to address the toxicological data requirements for propane-1,2,3-triol and its esterification products with formic acid (EC No. 701-316-8) in an analogue read-across approach. The basis for this read-across approach is that, upon oral administration, the target substance is expected to undergo stepwise transformation by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to free glycerol, with formic acid being released at each step, as illustrated in Figure 1. The toxicity of the glycerol constituent/metabolite will be assessed using information on glycerol, and the toxicity of the formic acid metabolite will be assessed using information on sodium formate, potassium formate, potassium diformate, calcium formate, ethylene diformate, ethylene glycol and formic acid.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Target Substance: Propane-1,2,3-triol and its esterification products with formic acid; 701-316-8
Source Substance 1: Propane-1,2,3-triol ; 200-289-5 ; 56-81-5
Source Substance 2: Formic acid, sodium salt (1:1) ; 205-48-0 ; 141-53-7
Source Substance 3: Formic acid, potassium salt (1:1) ; 209-677-9 ; 590-29-4
Source Substance 4: Formic acid, potassium salt (2:1) ; 243-934-6 ; 20642-05-1
Source Substance 5: Formic acid, calcium salt (2:1) ; 208-863-7 ; 544-17-2
Source Substance 6: 1,2-Ethanediol, 1,2-diformate ; 211-077-7 ; 629-15-2
Source Substance 7: 1,2-Ethanediol ; 203-473-3 ; 107-21-1
Source Substance 8: Formic acid ; 200-579-1 ; 64-18-6
[See attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details.]

The TS is a UVCB substance of 100% purity. On this basis, the source substances collectively represent 100% w/w of the target substance. The purities of the samples of source substances that were tested are not specifically known, but it is assumed that they would not have been sufficiently impure as to substantially affect the study results. On this basis, the applicability of the data on the source substances to the TS is not expected to be compromised by the presence of impurities in any of the substances.

3. ANALOGUE APPROACH JUSTIFICATION
The basis for this read-across approach is that, upon oral administration, the TS is expected to undergo stepwise hydrolysis by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to the free glycerol constituent, with formic acid being released at each step.
The TS is manufactured from a 1:1 molar ratio of glycerol and formic acid reactants and will therefore metabolize back to those same proportions of those same reactants. An exposure of an organism to the TS is therefore considered to be essentially equivalent to an exposure to a 1:1 molar mixture of glycerol and formic acid.

Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details as to how the source substances relate to the target substance.

For the following toxicity endpoints:
8.2 serious eye damage / eye irritation
8.3 skin sensitisation
8.5.1 acute toxicity by oral route
8.4.1 in vitro gene mutation study in bacteria;
8.4.2 mutagenicity: in vitro cytogenicity study in mammalian cells;
8.4 mutagenicity: in vivo genotoxicity;
8.6.3 long-term repeated dose toxicity: ≥ 12 months; and
8.7.2 developmental toxicity
information on the glycerol constituent/metabolite and the formic acid metabolite of the target substance will be used to predict the properties of the target substance.

4. DATA MATRIX
Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for data matrix details.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Species / strain:

S. typhimurium, other: various strains

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Conclusions:

It is reasonable to expect that the target substance will also not cause mutagenic effects in bacterial systems.

Executive summary:

The analogue source substance SS1 at concentrations of up to 50.0 mg/plate (50,000 μg/plate) was tested in an Ames assay using Salmonella typhimurium strains TA92, TA1535, TA100, TA1537, TA94, and TA98 both in the presence and absence of S9-mix (Ishidate, et al., 1984). Duplicate plates were used for each of the concentrations of the samples and phosphate buffer was used as a solvent. No significant increases in the number of revertant colonies were detected in any S. typhimurium strains at the maximum concentration. The study authors concluded that SS1 was not mutagenic under the conditions employed in this test.

A bacterial reverse mutation assay using S. typhimuriam strains TA100, TA1535, TA97, and TA98 conducted with buffered solutions of SS8 was reported to show no evidence of mutation in response to treatment of up to 3,333 μg/plate (Zeiger, et al., 1992). Slight clearing of the background lawn was observed at and above 1,000 μg/plate in strains TA97 and TA1535 with metabolic activation. Similarly, cytotoxicity was observed at 3,333 μg/plate in strains TA98 and TA100 with metabolic activation. Negative and positive controls indicated that the system was properly working.

In an Ames assay, the analogue source substance SS6 was tested using a plate incorporation method at doses ranging from 0 to 5,000 μg/plate in S. typhimurium strains TA1535, TA1537, TA98, TA100 and Escherichia coli strain WP2uvrA in the presence and absence of an externally added rat metabolic activation system (S9-mix) (Harlan Laboratories, 2012). In both assays no precipitates were observed either in the presence or absence of S9-mix. No visible reduction of the background lawn was observed at any concentration in all strains, in the presence and absence of S9-mix. There were no significant increases in the frequency of revertant colonies in all strains at any concentration, both in the presence and absence of S9-mix. The study authors concluded that the analogue source substance SS6 was not mutagenic under the conditions employed in this test.

On the basis of the information presented above that the source substances are without mutagenic activity in bacterial systems, it is reasonable to expect that the target substance will also not cause mutagenic effects in bacterial systems.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

It can be concluded that the target substance is not genotoxic in vivo.

Link to relevant study records

Reference

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

This endpoint study record is part of a Weight of Evidence approach comprising of read-across from three studies for one analogue source substance. The results of the read-across studies agree as to the potential for genetic toxicity and are sufficient to fulfil the information requirements as further explained in the provided genetic toxicity endpoint summary.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Data for propane-1,2,3-triol (glycerol; CAS No. 56-81-5), formic acid, sodium salt (1:1) (sodium formate; CAS No. 141-53-7), formic acid, potassium salt (1:1) (potassium formate; CAS No. 590-29-4), formic acid, potassium salt (2:1) (potassium diformate; CAS No. 20642-05-1), formic acid, calcium salt (2:1) (calcium formate; CAS No. 544-17-2), 1,2-ethanediol, 1,2-diformate (ethylene diformate; CAS No. 629-15-2), 1,2-ethanediol (ethylene glycol; CAS No. 107-21-1) and formic acid (CAS No. 64-18-6) is used to address the toxicological data requirements for propane-1,2,3-triol and its esterification products with formic acid (EC No. 701-316-8) in an analogue read-across approach. The basis for this read-across approach is that, upon oral administration, the target substance is expected to undergo stepwise transformation by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to free glycerol, with formic acid being released at each step, as illustrated in Figure 1. The toxicity of the glycerol constituent/metabolite will be assessed using information on glycerol, and the toxicity of the formic acid metabolite will be assessed using information on sodium formate, potassium formate, potassium diformate, calcium formate, ethylene diformate, ethylene glycol and formic acid.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Target Substance: Propane-1,2,3-triol and its esterification products with formic acid; 701-316-8
Source Substance 1: Propane-1,2,3-triol ; 200-289-5 ; 56-81-5
Source Substance 2: Formic acid, sodium salt (1:1) ; 205-48-0 ; 141-53-7
Source Substance 3: Formic acid, potassium salt (1:1) ; 209-677-9 ; 590-29-4
Source Substance 4: Formic acid, potassium salt (2:1) ; 243-934-6 ; 20642-05-1
Source Substance 5: Formic acid, calcium salt (2:1) ; 208-863-7 ; 544-17-2
Source Substance 6: 1,2-Ethanediol, 1,2-diformate ; 211-077-7 ; 629-15-2
Source Substance 7: 1,2-Ethanediol ; 203-473-3 ; 107-21-1
Source Substance 8: Formic acid ; 200-579-1 ; 64-18-6
[See attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details.]

The TS is a UVCB substance of 100% purity. On this basis, the source substances collectively represent 100% w/w of the target substance. The purities of the samples of source substances that were tested are not specifically known, but it is assumed that they would not have been sufficiently impure as to substantially affect the study results. On this basis, the applicability of the data on the source substances to the TS is not expected to be compromised by the presence of impurities in any of the substances.

3. ANALOGUE APPROACH JUSTIFICATION
The basis for this read-across approach is that, upon oral administration, the TS is expected to undergo stepwise hydrolysis by esterases in which the triformate constituent is converted into diformate constituents, diformate constituents are converted to monoformate constituents, and monoformate constituents to the free glycerol constituent, with formic acid being released at each step.
The TS is manufactured from a 1:1 molar ratio of glycerol and formic acid reactants and will therefore metabolize back to those same proportions of those same reactants. An exposure of an organism to the TS is therefore considered to be essentially equivalent to an exposure to a 1:1 molar mixture of glycerol and formic acid.

Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for further details as to how the source substances relate to the target substance.

For the following toxicity endpoints:
8.2 serious eye damage / eye irritation
8.3 skin sensitisation
8.5.1 acute toxicity by oral route
8.4.1 in vitro gene mutation study in bacteria;
8.4.2 mutagenicity: in vitro cytogenicity study in mammalian cells;
8.4 mutagenicity: in vivo genotoxicity;
8.6.3 long-term repeated dose toxicity: ≥ 12 months; and
8.7.2 developmental toxicity
information on the glycerol constituent/metabolite and the formic acid metabolite of the target substance will be used to predict the properties of the target substance.

4. DATA MATRIX
Refer to the attached JUSTIFICATION FOR READ-ACROSS OF TOXICOLOGICAL INFORMATION for data matrix details.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not specified

Conclusions:

It can be concluded that the target substance is not genotoxic in vivo

Executive summary:

The assessment of the potential for chemicals to cause damage to DNA is generally conducted in a tiered fashion (Ashby, 1996) whereby the initial assessment is made through the use of in vitro tests, often in bacteria or cultured mammalian cells. Chemicals that produce negative results in these tests are generally not assessed further. If the results of the in vitro test(s) are positive (i.e., suggesting mutagenic activity), chemicals may then be tested in one or more in vivo assays involving whole animals whereby the exposure to the chemical of interest incorporates pharmacokinetics as well as appropriate biotransformation products (Ashby, 1996; Ashby and Tennant, 1991).

As discussed elsewhere in this dossier, in vitro data for reverse mutation in bacteria and in vitro chromosome aberration data were identified for the analogue source substances propane-1,2,3-triol, formic acid, potassium salt (2:1), 1,2-ethanediol, 1,2-diformate and formic acid. Based on the available data, the target substance is considered to possess no mutagenic or clastogenic effects.

In addition to the in vitro data available on the analogue source substances, there are unpublished in vivo genotoxicity data available on analogue source substance formic acid, potassium salt (2:1) (OECD SIDS, 2008). Also, analogue source substance formic acid, potassium salt (2:1) has been tested in a 2-year chronic toxicity/oncogenicity assay in rats and mice (OECD SIDS, 2008).

The analogue source substance formic acid, potassium salt (2:1) did not increase percent of micronuclei in an in vivo rat bone marrow micronucleus test performed in accordance with OECD Test Guideline 474 when tested at doses of up to 50 mg/kg bw (OECD SIDS, 2008). It was concluded that SS4 did not increase the percentage of micronuclei in an in vivo rat bone marrow micronucleus test.

The analogue source substance formic acid, potassium salt (2:1) was tested for chronic toxicity and oncogenicity in rats and mice (OECD SIDS, 2008). Crl:HanWist(Glx:BRL)BR rats (50/sex/group) were administered 0, 50, 400 and 2,000 mg/kg bw/day of SS4 for 104 weeks and Crl:CD-1(ICR)BR mice (51/sex/group) were administered 0, 50, 400 and 2,000 mg/kg bw/day of SS4 for 80 weeks. The study authors concluded that no tumors of unusual nature or incidence indicative of specific target organ carcinogenicity were observed in the stomach or any other tissue at any concentration level in any species or sex.

The lack of carcinogenic effect of formic acid, potassium salt (2:1) is consistent with the in vitro and in vivo genotoxicity data on this analogue source substance indicating that it does not have genotoxic activity.

Overall, the in vivo data available on analogue formic acid, potassium salt (2:1), a terminal hydrolysis product of the target substance, show it to have no genotoxic potential. From this, it is further considered that the target substance would likewise not be genotoxic.

Beyond the test data available on the analogue source substances, the target substance does not contain any structural alerts that are indicative of mutagenic, genotoxic or carcinogenic potential (Ashby and Tennant, 1991; Tennant and Ashby, 1991; Ashby, 1996; Benigni and Bossa, 2008). An examination of the structure of the target substance clearly shows the UVCB mixture of glycerol and its formate esters.

The available information on the target substance clearly demonstrate a lack of mutagenic and genotoxic activity either in the presence or absence of an exogenous source of metabolic activation, as supported by a lack of mutagenicity and genotoxicity in several in vitro assays in bacterial and mammalian cell systems on the analogue source substances. Moreover, a structural analogue formic acid, potassium salt (2:1) related to the target substance has been tested in an in vivo micronucleus assay and found to be without genotoxic activity. Furthermore, the chronic toxicity/oncogenicity studies on an formic acid, potassium salt (2:1) did not show any increased incidence of tumor due to treatment. This is consistent with a lack of genotoxicity of these analogue source substances.

In addition to the available in vitro and in vivo test data on analogue source substances, the target substance is not structurally related to known mutagens or carcinogens.

Based on the preceding information and assessment, it can be concluded that the target substance is not genotoxic in vivo.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

The assessment of the potential for chemicals to cause damage to DNA is generally conducted in a tiered fashion (Ashby, 1996) whereby the initial assessment is made through the use of in vitro tests, often in bacteria or cultured mammalian cells. Chemicals that produce negative results in these tests are generally not assessed further. If the results of the in vitro test(s) are positive (i.e., suggesting mutagenic activity), chemicals may then be tested in one or more in vivo assays involving whole animals whereby the exposure to the chemical of interest incorporates pharmacokinetics as well as appropriate biotransformation products (Ashby, 1996; Ashby and Tennant, 1991).

As discussed elsewhere in this dossier, in vitro data for reverse mutation in bacteria and in vitro chromosome aberration data were identified for the analogue source substances propane-1,2,3-triol, formic acid, potassium salt (2:1), 1,2-ethanediol, 1,2-diformate and formic acid. Based on the available data, the target substance is considered to possess no mutagenic or clastogenic effects.

In addition to the in vitro data available on the analogue source substances, there are unpublished in vivo genotoxicity data available on analogue source substance formic acid, potassium salt (2:1) (OECD SIDS, 2008). Also, analogue source substance formic acid, potassium salt (2:1) has been tested in a 2-year chronic toxicity/oncogenicity assay in rats and mice (OECD SIDS, 2008).

The analogue source substance formic acid, potassium salt (2:1) did not increase percent of micronuclei in an in vivo rat bone marrow micronucleus test performed in accordance with OECD Test Guideline 474 when tested at doses of up to 50 mg/kg bw (OECD SIDS, 2008). It was concluded that SS4 did not increase the percentage of micronuclei in an in vivo rat bone marrow micronucleus test.

The analogue source substance formic acid, potassium salt (2:1) was tested for chronic toxicity and oncogenicity in rats and mice (OECD SIDS, 2008). Crl:HanWist(Glx:BRL)BR rats (50/sex/group) were administered 0, 50, 400 and 2,000 mg/kg bw/day of SS4 for 104 weeks and Crl:CD-1(ICR)BR mice (51/sex/group) were administered 0, 50, 400 and 2,000 mg/kg bw/day of SS4 for 80 weeks. The study authors concluded that no tumors of unusual nature or incidence indicative of specific target organ carcinogenicity were observed in the stomach or any other tissue at any concentration level in any species or sex.

The lack of carcinogenic effect of formic acid, potassium salt (2:1) is consistent with the in vitro and in vivo genotoxicity data on this analogue source substance indicating that it does not have genotoxic activity.

Overall, the in vivo data available on analogue formic acid, potassium salt (2:1), a terminal hydrolysis product of the target substance, show it to have no genotoxic potential. From this, it is further considered that the target substance would likewise not be genotoxic.

Beyond the test data available on the analogue source substances, the target substance does not contain any structural alerts that are indicative of mutagenic, genotoxic or carcinogenic potential (Ashby and Tennant, 1991; Tennant and Ashby, 1991; Ashby, 1996; Benigni and Bossa, 2008). An examination of the structure of the target substance clearly shows the UVCB mixture of glycerol and its formate esters.

The available information on the target substance clearly demonstrate a lack of mutagenic and genotoxic activity either in the presence or absence of an exogenous source of metabolic activation, as supported by a lack of mutagenicity and genotoxicity in several in vitro assays in bacterial and mammalian cell systems on the analogue source substances. Moreover, a structural analogue formic acid, potassium salt (2:1) related to the target substance has been tested in an in vivo micronucleus assay and found to be without genotoxic activity. Furthermore, the chronic toxicity/oncogenicity studies on an formic acid, potassium salt (2:1) did not show any increased incidence of tumor due to treatment. This is consistent with a lack of genotoxicity of these analogue source substances.

In addition to the available in vitro and in vivo test data on analogue source substances, the target substance is not structurally related to known mutagens or carcinogens.

Based on the preceding information and assessment, it can be concluded that the target substance is not genotoxic in vivo.

Justification for classification or non-classification

As per Regulation (EC) 1272/2008 as amended, the target substance does not meet the criteria for classification.

The target substance is not genotoxic in vivo.