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

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

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.

Justification for type of information:

Justification cf. field "any other information on results incl. tables"

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

GLP compliance:

yes (incl. QA statement)

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

37208-53-0

Cas Number:

37208-53-0

IUPAC Name:

37208-53-0

Constituent 2

Reference substance name:

2,2',2''-Nitrilotriethanol, propoxylated

EC Number:

500-094-8

EC Name:

2,2',2''-Nitrilotriethanol, propoxylated

IUPAC Name:

500-094-8

Details on test material:

-

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

- Amount of vehicle (if gavage): 5 ml/kg bw

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The content of the test item was assumed to be nominally 100% for calculation.
Before the start of the study formulations containing the test item in concentrations
of 2 mg/mI and 200 mg/ml were analyzed to determine homogeneous distribution
(not for the 2mg/ml formulation as it was a solution), content and stability of the test
item in tap water. During the study homogeneity and content was checked twice.

Duration of treatment / exposure:

31 days

Frequency of treatment:

once daily

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 300 and 1000 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

five

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The dose levels used were based on the results of a pilot study. During this study Wistar rats (2 males and 2 females per dose group) received the test substance in doses of O, 65, 160, 400, 1000 mg/kg for a period of two weeks. No clinical findings or relevant effects on body weight development were observed in this study.

Positive control:

no positive control

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes (incl. Open Field Observations (OFO))
- Time schedule: day 8, 15, 22, 28

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION: YES
- Time schedule for examinations: weekly

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: once, day 30
- How many animals: all dose groups incl. controls

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: once, day 30
- How many animals: all dose groups incl. controls

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: FOB: once, day 25; MA: once, day 29
- Dose groups that were examined: all dose groups incl. controls
- Battery of functions tested: Functional Observational Battery (FOB); Motor Activity (MA)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (all dose groups and controls)

ORGAN Weights:
Adrenals, brain, epididymides, heart, kidneys, Liver, Ovaries, Spleen, Testes, Thymus, uterus

Fixed organs:
Adrenals, aorta, brain (cerebrum, cerebellum, ponslmedulla), epididymides, esophagus, eyes, eyelids, extraorbital lachrymal glands, femur, harderian glands, head (with nasal and paranasal cavities), heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, larynx, liver, lymph nodes (mandibular, bronchial/hilus, and mesenteric), lung, mamma, optical nerves, ovaries, oviducts, pancreas, pharynx, pituitary, prostate, salivary glands, sciatic nerve, seminal vesicles (incl. coagulating glands), skeletal muscle (thigh), skin (mammary and muzzle), spinal cord (cervical, thoracic, lumbar), spleen, sternum, stomach (forestomach and glandular stomach), testes, thymus, thyroids (including parathyroid glands), tongue, trachea, ureter, urethra, urinary bladder, uterus with uterine cervix, vagina, Zymbal’s glands and all organs or tissues with macroscopic findings.

HISTOPATHOLOGY: Yes (high dose group and controls)
- Microscopic: Adrenals, brain (cerebrum, cerebellum, ponslmedulla), epididymides, femur, heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, liver, lung, lymph nodes, ovaries, oviducts, pancreas, pituitary, prostate, salivary glands, sciatic nerve, seminal vesicles (incl. coagulating glands), skeletal muscle (thigh), skin (mammary and muzzle), spinal cord (cervical, thoracic, lumbar), spleen, sternum, stomach (forestomach and glandular stomach), testes, thymus, thyroids (including parathyroid glands), trachea, urinary bladder, uterus with uterine cervix, and all organs or tissues with macroscopic findings. Slides were prepared from the first five animals of all groups and evaluated from the control and the high concentration group.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

Haematology:

Differential blood count revealed as the only conspicuous finding, that the number of leucocytes and lymphocytes was highest in high dose males but was lowest in high dose females. However, these differences were slight compared to the differences between the means of historical control values and the upper 2 s-range in males and the lower 2s-range in females, respectively. Furthernore, the deviations from control value were in opposite directions in males and females and histopathological examinations revealed no corresponding findings. For these
reasons a toxicological relevance was not inferred from these data.

Clinical chemistry:
Clinical aboratory tests revealed a significantly increased activity of alanine aminotransferase in females at 1000 mg/kg. However, the difference to control was relatively slight and histopathological examination of the liver produced no evidence for a treatment-related effect. Therefore, a toxicological relevance is not assumed. Determination of substrates showed the plasma creatinine concentration in males at 1000 mg/kg to be significantly decreased and in all treated female groups to be significantly increased. However, the differences to the respective control value were slight, no dose dependence was present in females, the deviation from the respective control group pointed in opposite directions in males and females and histopathological examination of kidneys produced no corresponding finding. On the basis of these results this was was not considered to be of toxicological relevance.

Histopathology:
The histopathological evaluation revealed a slightly more pronounced hypertrophy of the follicular cell epithelium in the thyroid gland of fernales ofthe high dose, in which not only centrally located follicles appeared hypertrophic but also follicles of the periphery. Hypertrophy was observed to a minimal degree also in females of the other dose groups including one control animal. Due to the slightly increased severity grade in females ofthe high dose group, an effect of the test substance cannot be completely ruled out. Such minimal changes are regarded to be caused by substances that interfere with general metabolic processes and are so far assessed as indirect and adaptive effects. If at all the findings in the present study were related to the treatment, they are therefore not considered as a primary adverse effect on thyroids. However, due to the missing dose response (incidence for follicular cell hypertrophy was: 1 /3/ 1 /3) and the lack of any other treatment-related changes a spontaneous occurrence e.g. by a general variability seems more likely.

Effect levels

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

gross pathology

haematology

histopathology: neoplastic

histopathology: non-neoplastic

mortality

organ weights and organ / body weight ratios

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

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 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).

Applicant's summary and conclusion

Executive summary:

In a repeated dose oral toxicity study in rats (Wistar, OECD TG 407), 2,2',2" -Nitrilotriethanol, propoxylated was adiministered via gavage to 5 rats/sex/dose at 0, 100, 300, 1000 mg/kg bw for 4 weeks.. No death was observed in either sex. No clinical effects were observed in both sex of all dose groups.There was no effect observed upon haematological, clinical biochemistry or macroscopic examination at any dose. Based on these results the NOAEL was considered to be 1000 mg/kg bw/day. If at all the slight changes in thyroids of females at 1000 mg/kg were related to the treatment, they are regarded as an indirect and adaptive effect.