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

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

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 these co-initiated NLP polyols

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 Glycerin) 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).

Results 'read across' from study on N,N', N''-nitrilotriethanol, propoxylated, as permitted by Annex XI para 1.5, based on the justification in the report from Paul Illing Consultancy Services Ltd and Marlin Consultancy (Illing and Barratt, 2007, revised 2009a; 2009b). The report identifies that N,N',N''-nitrilotriethanol, propoxylated is the most bioavailable of the NLP polyols linked by an ether group, and that the lack of reproductive toxicity seen for it and for the components (sucrose, glycerin and propane-1,2 -diol) of sucrose, PO and gycerin, PO can be considered representative of the lack of toxicity of the ether linked NLP polyol. For further details concerning the grouping, consult the reports of Barratt and Illing in section 13 of IUCLID data set.

Adequate testing has been undertaken on a sufficient number of the core substances and repeating units. None of the tested core substances and none of the repeating units is classifiable as a reproductive toxin. Hence it would be anticipated that the NLP polyols, as a category, would also not be reproductive toxins.

The NLP polyol linked by an ether linkage (category 1), nitrilotriethanol, propoxylated was tested to fulfil the requirements of Annex VIII (>10 tonnes/y). The results from this screening reproductive test confirmed the pre-existing information. Sufficient data exist to permit robust conclusions that the substances are not reproductive toxins and that no further testing is required (Barrat and Illing, 2009b).

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

Toxicity to reproduction of Nitrilotriethanol, propoxylated was investigated in an OECD 421 screening study. Treatment with 2,2',2''-Nitrilotriethanol, propoxylated resulted in increased incidence of salivation at the 1000 mg/kg dose in both genders and possibly transiently in females at 300 mg/kg dose group. Femalse of the 1000 m/kg dose group showed body weight loss during lactation for which treatment relationship, although unlikely, could not be completely excluded.

The reported NOAEL for male (general toxicity) 1000 mg/kg bw/day

The reported NOAEL for female (general toxicity): 300 mg/kg bw/day

The registrant considers the mild bodyweight loss observed with females at the highest dose group (1000 mg/kg bw/day) as non adverse treatment related effect as it follows a statistically significant increased body weight gain, as compared to control, in the premating phase. Possible minor effects on body weight do not constitute 'serious damage', the requirement relevant to classification.

The No Adverse Effect Level is therefore concluded to be >=1000 mg/kg bw/day.

The reported NOAEL (reporduction/developmental toxicity): 1000 mg/kg bw/day.

Short description of key information:

Target substance is unlikely to be toxic as a result of the read-across from a reproductive toxicity study of a source substance. NOAEL  >=1000 mg/kg bw/day.

Effects on developmental toxicity

Additional information

Adequate testing has been undertaken on the core substances and repeating units. None of the tested core substances and none of the repeating units is classifiable as a reproductive toxin. Hence it would be anticipated that the NLP polyols, as a category, would also not be reproductive toxins.

The NLP polyols linked by an ether linkage (category 1), nitrilotriethanol, propoxylated, propylidynetrimethanol, ethoxylated and ethane-1,2 -diol, propoxylated were tested to fulfil the requirements of Annex VIII (>10 tonnes/y). The results from these screening reproductive tests and the developmental toxicity study confirmed the pre-existing information. Sufficient data exist to permit robust conclusions that the substances are not developmental toxins and that no further testing is required (Illing and Barratt, 2009).

Justification for classification or non-classification

Based on the results of the available reproductive toxicity study with a member of the grouping "Polyols linked to the core substance by an ether linkage", classification of reproductive toxicity 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.