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 toxic as a result of the read-across from acute oral and dermal studies 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 attachments in 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 physical-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 (with 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).

 Oral exposure route - read-across with other polyols linked to the core substance by an ether linkage:

In an acute oral toxicity study according to OECD Guideline 401, 5 male and 5 female Wistar rats were exposed to 2000 mg Sucrose, PO/kg bw. No clicinal signs were observed, resulting in a LD50 > 2000 mg/kg bw (Bayer, 1995).

In an acute oral toxicity study according to Federal register, august 22, 1978, 43:37355-6, male and femal Sprague-Dawley rats were exposed to 0, 650, 1250, 2500, 5000 mg/kg bw (6 animals per sex per dose). No clinical signs were observed, resulting in a LD50 > 5000 mg Sucrose, PO/kg bw (Dow, 1982).

Acute toxicity via the oral route was low and the reported LD50 is >2000 mg Glycerol, PO/kg bw in two studies according to OECD guideline 401 and in one study according to OECD 423. No signs of overt systemic toxicity were observed at the limit dose of 2000 mg Glycerol, PO/kg bw.

Dermal exposure route - read-across with other polyols linked to the core substance by an ether linkage:

In an acute dermal toxicity study according to OECD Guideline 434, 4 male and 4 female New Zealand White rabbits were exposed to 5000 mg Sucrose, PO/kg bw. No clinical signs were observed, resulting in a LD50 > 5000 mg Sucrose, PO/kg bw (Dow, 1982).

The acute toxicity via the dermal route was low and the reported LD50 is >2000 mg Glycerol, PO/kg bw in a study according to OECD guideline 402.

 

Justification for classification or non-classification

Based on the results of the available acute toxicity studies with members of the grouping "Polyols linked to the core substance by an ether linkage", classification of acute toxicity for the oral or dermal route 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.