Reaction mass of 5,8,11,14-Tetraoxaoctadecane and 5,8,11,14,17-Pentaoxaheneicosane

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

2011-06-06 to 2011-12-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Non GLP; equivalent to OECD 414 with deviation; scientifically well performed study. Rationale for grouping: structural similarity given by the presence of ”butyl-O-CH2CH2 -O-“ at terminal position; systemic exposure to 2-butoxyacetic acid and/or butoxyethoxyacetic acid as common mode of action; comparable toxicity profiles after prolonged exposure

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

8 animals per group

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No. 440/2008, L 142, Annex Part B, May 30, 2008

Deviations:

yes

Remarks:

8 animals per group

Principles of method if other than guideline:

The number of animals was 8 per group instead of 20.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Bis(2-butoxyethyl) ether

EC Number:

204-001-9

EC Name:

Bis(2-butoxyethyl) ether

Cas Number:

112-73-2

Molecular formula:

C12H26O3

IUPAC Name:

1,1'-[oxybis(ethane-2,1-diyloxy)]dibutane

Constituent 2

Reference substance name:

DEGDBE

IUPAC Name:

DEGDBE

Test material form:

gas under pressure: refrigerated liquefied gas

Details on test material:

Name: Diethyleneglycoldibutylether
CAS No.: 112-73-2
Chemical Name: Bis(2-butoxyethyl)ether
Active Components: 100%
Physical State: liquid
pH: 6, 5-7, 5 (25oC, 100 g/L i-propanol/ water 4:1)
Colour: Colourless
Storage: Room Temperature (RT)

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, 97633 Sulzfeld, Germany
- Age at study initiation: approx. 11-12 weeks old
- Housing: Full barrier in an air-conditioned room
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 55 ± 10%
- Air changes (per hr): 10 x / hour
- Photoperiod (hrs dark / hrs light): 12 hours light, 12 hours dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

The animals were acclimatised for at least five days. After acclimatisation, females were paired with males as per the ratio of 1:2 (male to female). Females were paired for cohabitation in batches in order to regularize the number of animals for terminal sacrifice on particular day. The subsequent morning and the next morning onwards, the vaginal smear of female was checked to confirm the pregnancy. The day on which sperms were observed in the vaginal smear was considered as gestation day ‘0’. Mated females were assigned in an unbiased manner to the control and treatment groups ensuring that group mean body weights were comparable with each other.

Duration of treatment / exposure:

in females from the Gestation Day (GD) 5 to GD 19

Frequency of treatment:

daily

Duration of test:

On gestation day 20 caesarean section was performed

Doses / concentrations

Remarks:

Doses / Concentrations:
250, 500, 750 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

8 females per dose

Control animals:

yes

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least once a day
- morbidity and mortality

DETAILED CLINICAL OBSERVATIONS: Yes / No / No data
- Time schedule:at least once a day

BODY WEIGHT:
- The sperm positive females were weighed on GD 0, 5, 8, 11, 14, 17 and 20.
- Males were not weighed in this study.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption of sperm positive females was measured on GD 5, 8, 11, 14, 17 and 20. The food consumption was presented for period 0-5, 5-8, 8-11, 11-14, 14-17, and 17-20.
- The food consumption was measured neither for males during the entire study nor for both male and females during the mating period.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- structural abnormalities or pathological changes
- uteri, gravid uterus with cervix, corpora lutea
- Males were sacrificed at any time after completion of the mating of all females without any observations

Ovaries and uterine content:

The uterine contents were examined for embryonic or fetal deaths and the number of viable fetuses. The degree of resorption (late and early) was ascertained in order to help estimate the relative time of death of the conceptus.
The position /number of fetuses in each uterine horn were also be recorded.

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Head examinations: Yes

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Mortality:
- no mortality

Clinical observation:
- salivation, moving the bedding, weight loss and piloerection at 500 and 750 mg/kg bw

Body weight development:
-significant body weight decrease between GD5 to 8 at 500 and 750 mg/kg bw
- significant body weight gain decrease from GD5 onwards at 500 and 750 mg/kg bw

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

2

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Prenatal data:
- inceased pre- and postimplantation loss at 500 and 750 mg/kg bw
- decreased number of live pubs at 500 and 750 mg/kg bw
- decreased mean litter weight at 750 mg/kg bw

Fetal external examination:
- no treatment related effect

Fetal visceral examination
- no treatment related effect.

Fetal skeletal examination:
- increased incidences of abnormality at 500 and 750 mg/kg bw

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Maternal toxicity: Table 1 - 3

Table 1: Summary of Clinical Observation (Number of animals affected)
Clinical Findings	Control n=8	250 mg/kg bw n=8	500 mg/kg bw n=8	750 mg/kg bw n=10
Alopecia	2	1	1	0
Aggressive behaviour	1	0	0	0
Piloerection	0	2	1	6
Injury	0	1	0	0
Salivation	0	1	4	9
Moving the bedding	0	0	3	10
Increased spontaneous activity	0	0	0	1
Weight loss	0	0	0	2
Dehydration	0	0	0	1
Reduced spontanoues activity	0	0	0	1
Bloody urinigenital region	0	0	0	1
Bloody urine	0	0	0	1

Table 2: Summary of Gestation Body Weight [g]
Gestation Day	Control   n=8	250 mg/kg bw n=8	500 mg/kg bw n=6	750 mg/kg bw n=10
0	222 ± 5	219 ± 12	215 ± 3	218 ± 8
5	235 ± 8	235 ± 17	233 ± 5	233 ± 10
8	242 ± 9	239 ± 17	231 ± 11	217 ± 15
11	253 ± 9	249 ± 14	243 ± 8	233 ± 14
14	267 ± 9	263 ± 16	254 ± 12	249 ± 13
17	292 ± 8	284 ± 16	274 ± 16	271 ± 16
20	321 ± 10	318 ± 18	300 ± 25	291 ± 30

Table 3: Summary of Gestation Body Weight Gain [g]
Gestation Day	Control   n=8	250 mg/kg bw n=8	500 mg/kg bw n=6	750 mg/kg bw n=10
0 to 20	99 ± 9	99 ± 11	85 ± 25	73 ± 28
0 to 5	13 ± 4	16 ± 6	18 ± 4	16 ± 5
5 to 8	7 ± 4	4 ± 5	-2 ± 8	-16 ± 9
8 to 11	11 ± 2	10 ± 4	12 ± 5	16 ± 4
11 to 14	14 ± 4	14 ± 3	11 ± 5	16 ± 6
14 to 17	25 ± 5	21 ± 4	20 ± 6	23 ± 8
17 to 20	29 ± 7	35 ± 5	26 ± 9	19 ± 15

Prenatal Data: Table 4

Table 4: Summary of Prenatal Data
	Control   n=8	250 mg/kg bw n=8	500 mg/kg bw n=6	750 mg/kg bw n=10
Terminal Body Weight [g]	320 ± 10	318 ± 18	300 ± 25	291 ± 30
Uterus Weight[g]	67 ± 7	64 ± 8	43 ± 25	57 ± 20
Adjusted Weight [g]	254 ± 12	254 ± 16	257 ± 20	233 ± 16
Corpora Lutea	13.88 ± 1.25	13.50 ± 1.07	14.33 ± 1.21	13.70 ± 0.82
Implantations	12.75 ± 1.58	12.63 ± 1.06	10.33 ± 5.35	12.90 ± 0.99
Live Fetuses	12.38 ± 1.85	12.13 ±1.46	9.17 ± 4.88	11.00 ± 3.94
Dead Fetuse	0	0	0	0
Total Resorption	0.38 ± 0.74	0.50 ± 0.76	1.17 ± 1.47	1.90 ± 3.93
Pre Implantation Loss [%]	7.93 ± 9.71	6.13 ± 8.79	28.31 ± 36.62	5.79 ± 5.70
Post Implantation Loss [%]	3.04 ± 6.13	4.09 ± 6.24	11.18 ± 11.88	14.51 ± 30.25

 

Litter Data: Table 5

Table 5: Summary of Litter Weight Data
	Control  n=8	250 mg/kg bw n=8	500 mg/kg bw n=6	750 mg/kg bw n=10
Litter Mean Weight [g]	3.30 ± 0.22	3.22 ± 0.14	3.46 ± 0.38	2.75 ± 1.04
Total Litter Weight[g]	40.59 ± 4.13	39.05 ± 5.00	30.38 ± 14.71	33.57 ± 12.81

Table 6: Findings in Skeletal Examination; findings only with clearly increased incidences given
	Control   n = 49			250 mg/kg bw n=49			500 mg/kg bw n = 29				750 mg/kg bw n=51
	A	B	C	A	B	C		A	B	C	A	B	C
IO-4^thmetacarpal, both	0	0	0	3	6.1	2		6	20.7	3	19	37.3	8
IO-4^thsternebrum	15	30.6	1	19	38.8	7		8	27.6	4	39	76.5	8
IO-Frontal	0	0	0	4	8.2	4		9	31.0	3	19	37.3	7
IO-Hyoid	0	0	0	1	2.0	1		7	24.1	2	9	17.6	5
IO-Temporal, both	1	2.0	1	1	2.0	1		9	31.0	3	14	27.5	5
IO-Xiphoid	10	20.4	7	13	26.5	5		6	20.7	3	25	49.0	8
Rudimentary rib-14^th, both	3	6.1	4	2	4.1	2		6	20.7	5	2	3.9	2
Rudimentary rib-14^th, left	2	4.1	2	2	4.1	1		3	10.3	3	4	7.8	4
Rudientary rib-14^th, right	1	2.0	1	3	6.1	2		6	20.7	5	6	11.8	6
Waxy ribs	1	2.0	1	4	8.2	4		3	10.3	3	20	39.2	8

A: Total number of incidences for particular abnormality

B: % Incidence

C: Number of litters in group having at least one fetus with the particular abnormality

Applicant's summary and conclusion

Conclusions:

The developmental toxicity of DEGDBE was investigated according to OECD 414 with deviations of using limited number of animals. DEGDBE induced at 500 mg/kg bw and above reduced body weight and increased pre and post implantation loss, reduced mean litter weight and abnormalities/variations upon skeletal examination. At 250 mg/kg bw no maternal toxicity and no fetal toxicity was found.

Executive summary:

The developmental toxicity of the registration substance was assessed based on the data of the read-across supporting substance diethylenglycoldibutylether (DEGDBE).

The developmental toxicity of DEGDBE was investigated according to OECD 414 with deviations of using limited number of animals. Each eight pregnant rats were treated with DEGDBE per gavage at doses of 0. 250, 500, 750 mg/kg bw. The initial high dose level was 1000 mg/kg bw, but due to the severe sufferings of treated animals the dose level was adjusted to 750 mg/kg bw.

DEGDBE at 500 and 750 mg/kg bw induced transient body weight loss (gestation day 5 -8, ), reduced body weight gain, increased pre- and post-implantation loss, reduced live fetuses, reduced litter mean weight and increased incidences of findings upon skeletal examinations. No developmental toxicity in absence of maternal toxicity could be found. The NOAEL of 250 mg/kg bw was determined for maternal and fetal toxicity.

Based on the read-across approach, no developmental toxicity is predicted for the registration substance.