Oxy alkylation products of glycerol and sucrose with propylenoxid (>1 - <6.5 mol PO)

Endpoint summary

Description of key information

Target substance is unlikely to be irritating to the skin and eye as a result of the read-across from acute local irritation tests of source substances.

Additional information

Annex XI of Regulation 1907/2006 and the REACH Guidance (R 6.2) permits the grouping of chemicals (chemicals categorisation).Barratt and Illing (2007, revised 2009a; 2009b, see attachmentsin section 13 of IUCLID data set) set out justification for an initial grouping of the polyols (oligomers and polymers) using a named core substance, with varying numbers of attached propoxy groups (or propoxy and ethoxy groups). The properties of the core substance and the repeating unit should be reflected in the polyols. The repeating unit is essentially non-toxic. If there are toxic properties associated with a core substance, these properties should reduce with increasing numbers of repeating units (i.e. increasing molecular weight).If both the core substance and the repeating unit are non-toxic, it can be anticipated that there will be no toxicity in the polyol.

 

A second round of grouping was based on allocation of the NLP polyols formed from different named core substances to one of two categories. The first group was those NLP polyols linked to the core substance by an ether linkage (category 1) and the second group (category 2) was those linked by a secondary/tertiary amine linkage. Category 1 consists of:

·        Sucrose, propoxylated, >1-16.5 moles propoxylated

·        propylidyne trimethanol, propoxylated, >1-6.5 moles propoxylated

·        Glycerin, propoxylated, >1-6.5 moles propoxylated

·        Propan-1,2-diol, propoxylated, >1-4.5 moles propoxylated

·        Pentaerythritol, propoxylated, >1-8.5 mol propoxylated.

·        Nitrilotriethanol, propoxylated, 1-6.5 moles propoxylated.

For details see attached documents ‘Grouping of NLP Polyols and their toxicokinetics assessments’ (Barratt and Illing (2007, revised 2009a) and PROPOSALS FOR FURTHER TESTING FOR THE NLP ‘POLYOLS’ (2009b) in section 13 of IUCLID data set.

The registered substance is a complex substance (UVCB) which can be regarded as a mixture of Sucrose, PO and Glycerin, PO, two members of the grouping "NLP polyols linked to the core substance by an ether linkage" (= category 1). As, in all cases, the ether linked NLP polyols are non-toxic, it is anticipated that any mixture of them or any co-initiated polyol formed using a mixture of initiators will have a similar lack of toxicity. Thus the hazard profile for the multicomponent substance can be sufficiently described by the information of the individual constituents and it is unnecessary to test this co-initiated polyol.

The physico-chemical properties of these source substances and the target substance are very similar as displayed in Table 1.

Table 1: Comparison of physico-chemical properties of source substances with target substance
	Source Substances		Target Substance
	Glycerin + PO	Sucrose + PO	Glycerin + Sucrose + PO
Appearance	liquid	liquid	liquid
Melting point	no MP	no MP	no MP
Boiling point	Decomposition >= 290°C	no BP	Decomposition >= 210°C
Relative density	1.08 (20°C)	1.122 (20°C)	1.132 (20°C)
Partition coefficient	> -1.82 < -0.73	> -3.60 < -3.25	> -0.7 < 1.1
Water solubility	completely miscible	240 g/L (25°C)	completely miscible
Surface tension	53 nM/m (20°C; at 1 mg/L)	54.54 nM/m (20°C; at 1 mg/L)	61.3 nM/m (20°C; at 1 mg/L) (Glycerol + PO)
Flashpoint	163°C (no information on pressure available)	149.5°C (1003 hPa)	198°C (1013 hPa)
Auto flammability	305°C (1014 ha)	355°C (1000 hPa)	350°C (1008 hPa)
Flammability	no pyrophoric properties does not emit flammable gases in contact with water	no pyrophoric properties does not emit flammable gases in contact with water	no pyrophoric properties does not emit flammable gases in contact with water
Explosiveness	no explosive properties	no explosive properties	no explosive properties
Oxidising properties	no oxidising properties	no oxidising properties	no oxidising properties
Viscosity	560.6 mPa (20°C)	26.63 Pa s (20°C)	21.47 mPa s (20°C)

Therefore, in line with Annex XI, 1.2 of Regulation (EC) No 1907/2006, read-across (many-to-one) was chosen for the registered substance (Polyether Sucrose + Glycerin+ PO) and thus no toxicological study has been performed with registered substance itself.

The model being used to justify read-across (many-to-one) is that the toxicity of the polyether polyol is derived from the core substance (initiator) and the repeating unit. While for propoxylated polyols the repeating unit is probably not classifiable, any toxicological property requiring classification is derived from the core substance. The fact, that the target chemical is formed from core substances (Sucrose and Glycerol) which are the same for two source substances (Sucrose, PO and Glycerin, PO), suggests that there are no major differences between these source substances and the target substance which may affect the toxicological properties. Due to the closeness of the compounds, polyols grouping data (= source substances data) is lead for Polyether Sucrose + Glycerin + PO (= target substance) according to Table 2 (see section 13 of IUCLID data set).

Skin corrosion/irritation - read-across with other polyols linked to the core substance by an ether linkage:

Skin irritation study with Sucrose, PO was performed on the basis of the guidelines of the Federal Registry Sep 27th 1973 38:27019.No redness or swelling was observed on the skin of any of the 6 rabbits  after 24 hours exposure to the test material. Therefore, the primary irritation score was 0 out of possible 8. The test substance was classified as a non irritant on the basis of the scores.

Skin Irritation study with Glycerin, PO was performed in accordance to OECD 404. Very slight erythema (grade 1) was observed in one animal only at the 1 hour observation period. All test sites appeared normal at 24 hours.

Eye damage/irritation - read-across with other polyols linked to the core substance by an ether linkage:

Eye irritation study with Sucrose, PO was performed on the basis of the guidelines of the Federal Registry Aug 22nd 1978 . Slight redness of conjunctiva was observed 2/6 rabbits at the 1 and 2 days readings. No corneal injury was observed.  Upon instillation of TS rabbits experienced slight to moderate discomfort, characterized by blinking and/or rubbing the eye with a paw. No irritation was observed 3 days post-instillation.

Eye Irritation study with Glycerin, PO was performed in accordance to OECD 405. Conjuctival redness (grade 2) was observed in the eye of 2 rabbits at 1 hour post-instillation. Residual test material was observed around the treated eye of all rabbits 1 hour after treatment.All irritation fully reversed within 24 hours after dosing.

Effect level: empty Endpoint conclusion: Adverse effect observed

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Based on the results of the available skin and eye irritation studies with members of the grouping "Polyols linked to the core substance by an ether linkage", classification of skin corrosion/irritation and eye damage/irritation is not warranted for the target substance according to Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP)Regulation (EC) No.1272/2008.