1,3-Propanediol, 2,2-bis(hydroxymethyl)-, polymer with 2-(chloromethyl)oxirane, 2-propenoate

Endpoint summary

Additional information

For Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid a gene mutation assay in bacteria (Ames) according to OECD471 is available. No data exist for the test substance to evaluate its mutagenic potential in mammalian cells or ability to induce chromosome aberrations. Thus read across was performed to the following structurally similar multifunctional acrylates: 2-Propenoic acid, reaction products with pentaerythritol (PETIA, CAS 1245638-61-2) and Trimethylolpropane ethoxylated triacrylate (TMPeoTA, CAS 28961-43-5).

In comparison to Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid the read across substance 2-Propenoic acid, reaction products with pentaerythritol lacks the chain elements derived from 1-chloro-2,3 epoxipropane in between the pentaerythritol and acrylic acid groups. Consequently this lead to a lower molecular weight of app. 300g/mol compared to app 850g/mol for the oligomere. The molecular weight for TMPeoTA is 300-600g/mol, depending on the amount of ethoxylation, and thus in between the two former substances. All three substances are liquids with a low vapour pressure << 0.01hPa and low water solubility of approximately 500-900mg/l. The log Pow value increases with increasing chain length from 1.5-2.7 for PETIA to app. 3 for TMPeoTA to > 3 for Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid. All substances are moderate skin sensitizers, but due to the higher amount of acrylic acid on a weight per weight basis, which is presumably quickly hydrolysed, PETIA and to a lesser extent TMPeoTA show an increased irritation potential. While PETIA causes skin irritation, eye corrosion and low acute oral toxicity as a consequence of severe mucosal irritation / erosion, TMPeoTA only leads to eye irritation. Thus using data from PETIA and TMPeoTA is a reasonable worst case approach to evaluate the toxicity of Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid.

Gene mutation in bacteria

In a gene mutation assay in bacteria (Ames) according to OECD471 and GLP (BASF 2013) Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid did not lead to an increase in the number of his + or trp+ revertants in both, the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system. Concentrations up to 5000 µg/plate were tested in Salmonella strains TA 1535, TA 100, TA 1537, TA 98 and Escherichia coli 1412 uvrA. S9 fraction was prepared from aroclor induced rat liver.

Gene mutation in mammalian cells

PETIA was tested in an Mouse Lymphoma forward mutation assay with mammalian cells similar to OECD 476 and according to GLP (Cytec 1979) at doses of 0.016nl/ml to 0.5nl/ml without S9 and 0.125nl/ml to 25nl/ml with S9. Concentrations of 0.625nl/ml and above without S9 were completely lethal to the cells after 24h, while addition of S9 mix reduced cytotoxicity of the substance. An increase in mutant cells more than 2.5times above control values was observed with and without S9 mix at highly cytotoxic concentrations only, i.e., leading to relative growth of 13-23%. Less toxic concentration were not mutagenic. Colony sizes were not evaluated in this study, so it cannot be differentiated, if the mutagenic activity is due to a clastogenic or gene mutation potential of the test substance. Many members of the group of multifunctional acrylates are clastogenic in vitro at highly cytotoxic concentrations only, and results could not be confirmed in vivo. Based on this information and because of the data presented for TMPeoTA below, the positive result in the mouse lymphoma assay is believed to be due to clastogenicity.

TMPeoTA was also tested in a mouse lymphoma assay according OECD 476 and GLP. L5178Y TK +/- 3.7.2c mouse lymphoma cells were treated with the test substance at dose levels of 0.13 to 5µg/mL without activation and 7.5 to 55µg/mL with activation. The maximum dose level used was limited by the test substance induced toxicity. No precipitate of the test substance was observed at any of the dose levels. The vehicle (solvent) controls had acceptable mutant frequency values that were within the normal range for the L5178Y cell line at the TK +/- locus. The positive control materials induced marked increases in the mutant frequency indicating the satisfactory performance of the test and of the activity of the metabolising system. The test substance induced weak but reproducible toxicologically significant dose-related increases in the mutant frequency both with and without metabolic activation, in the first and second experiment. The mutagenic response was only observed in dose levels approaching the limit of acceptable toxicity. The increase in mutant frequency was predominantly due to small colony formation, indicating clastogenic activity resulting in structural chromosome damage.

Micronucleus test in vivo

The test substance Pentaerythritol triacrylat (PETA, Cas 3524-68-3) was tested in a Mammalian Erythrocyte Micronucleus Test with B6C3F1 mice for 3 month (NTP, 2005). Groups of 10 male and 10 female B6C3F1 mice were administered 0, 0.75, 1.5, 3, 6, or 12 mg pentaerythritol triacrylate/kg body weight in acetone 5 days per week for 14 weeks. One female vehicle control mouse was sacrificed during the first week of the study due to ataxia and one 1.5 mg/kg female died during week 8. Mean body weights of dosed groups were similar to those of the vehicle control groups. Irritation at the site of application occurred in the 6 and 12 mg/kg male groups. Hematology results indicated an increased neutrophil count consistent with an inflammatory response related to the dermatitis observed histopathologically. There also was a minimal decrease in the erythron (hematocrit, hemoglobin concentration, and erythrocyte count) likely secondary to the inflammatory skin process. Males and females administered 1.5 mg/kg or greater generally had increased incidences of epidermal hyperplasia, degeneration, and necrosis; dermal chronic active inflammation, sebaceous gland hyperplasia, and hyperkeratosis at the site of application. No increase in the frequency of micronucleated erythrocytes was observed in peripheral blood samples from B6C3F1 mice treated with pentaerythritol triacrylate by skin painting for 3 months.

PETIA was also applied dermally for 6 months to Tg/Ac (v-Ha-ras) heterozygous transgenic mice. The study has been disregarded, since the model has not been accepted for the assessment of cancerogenicity. Additionally, PETIA has been tested at concentrations that caused serious skin irritation in these mice, leading to sustained proliferation of the follicular epithelial cells, which are the precursor cells that give rise to papillomas in Tg.AC mice (Sistare, 2002). Doubts have been raised in several publications, if a positive result obtained in combination with skin irritation is related to a direct mutagenic potential of the test substance, since skin tumors were also observed in this mouse model following abrasion or a single incidence of full thickness wounding (Leder, 1990; Lynch, 2007).

The substance TMPeoTA was tested for chromosomal damage (clastogenicíty) and for the ability to induce spindle poison effects (aneugenic activity) in NMRI mice using the micronucleus test method according to OECD 474 and GLP (BASF, 2002). For this purpose, the test substance, dissolved in DMSO, was administered once orally to male animals at dose levels of 500 mg/kg, 1,000 mg/kg and 2,000 m g/kg body weight in a volume of 4 ml/kg body weight. No signs of toxicity were observed. Negative and positive control chemicals, i .e . cyclophosphamide for clastogenicity and vincristine for spindle poison effects, led to the expected number of polychromatic erythrocytes containing small or large micronuclei. Test substance administration did not lead to any increase in the number of polychromatic erythrocytes containing either small or large micronuclei compared to the concurrent negative control in all dose groups and at all sacrifice intervals and were within the range of the historical control data. No inhibition of erythropoiesis determined from the ratio of polychromatic to normochromatic erythrocytes was detected. Thus, under the experimental conditions chosen here, the test substance does not have any chromosome-damaging (clastogenic) effect, and there were no indications of any impaìrment of chromosome distribution in the course of mitosis (aneugenic activity) in bone marrow cells in vivo.

References

Leder A, Kuo A, Cardiff RD, Sinn E, Leder P (1990) v-Ha-ras transgene abrogates the initiation step in mouse skin tumorigenesis: effects of phorbol esters and retinoic acid. Proc Natl Acad Sci USA 87:9178–9182

Lynch D, Svoboda J, Putta S, Jofland HEJ, Chern W, Hansen L (2007) Mouse Skin Models for Carcinogenic Hazard Identification: Utilities and Challenges. Toxicol Pathol 35:853-864

Nylander-French LA, French JE (1998) Tripropylene glycol diacrylate but not ethyl acrylate induces skin tumors in a twenty-week short-term tumorigenesis study in Tg.AC (v-Ha-ras) mice. Toxicol Pathol 26:476–83.

Short description of key information:
in vitro
Ames: negative (OECD471, GLP, BASF 2013)
Mouse Lymphoma: positive (OECD 476, GLP, Cytec 1979, PETIA)
Mouse Lymphoma: positive (OECD 476, GLP, Cytec 2006, TMPeoTA)
in vivo
Mam Erythroz. Micronucleus Test: negativ (NTP 2005, PETA)
MNT: negative (OECD 474, GLP, BASF 2002, TMPeoTA)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid did not cause gene mutations in bacteria with or without addition of a metabolic activation system. Two structurally related substances from the group of multifunctional acrylates were positive in the mouse lymphoma assay at cytotoxic concentrations. Colony sizing indicated that these results are due to a clastogenic potential in vitro, which could not be confirmed in vivo. No increase in micronucleated erythrocytes was observed in mice treated dermally for 3 months with PETIA. A micronucleus test according to OECD 474 using TMPeoTA also did not lead to genotoxicity.

In summary, Pentaerythritol, olig. react. prod. with 1-chloro-2,3-epoxypropane, react. prod. with acrylic acid does not need to be classified according 67/548/EEC and CLP/EU-GHS for its mutagenic potential.