Bis(2-ethylhexyl) carbonate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

According to REACH regulation, Annex VIII, 8.7.1, column 2, a screening study for reproductive/developmental toxicity does not need to be conducted if a pre-natal developmental toxicity study is available. A pre-natal developmental toxicity study is available for the metabolite 2-Ethylhexanol.

According to REACH regulation, Annex IX, 8.7.3, a decision on the need to perform a two generation study at this tonnage level should be based on the outcome of all other relevant available data. In a pre-natal developmental toxicity study signs of embryo-/fetotoxicity as well as teratogenicity were only observed at dose levels where also maternal toxicity was present. Thus, the conduct of a two generation study is not justified.

There are no data gaps for the endpoint toxicity to reproduction.

Effects on developmental toxicity

Description of key information

A prenatal developmental toxicity study (OECD guideline 414, oral gavage, administration day 6-15 of gestation) in rat with the read-across substance 2-Ethylhexanol resulted in a NOAEL(maternal) of 130 mg/kg bw/d, a NOAEL(embryo-/fetotoxicity) of 130 mg/kg bw/d, a NOAEL(teratogenicity) of 650 mg/kg bw/d. 
Recalculation based on molecular weight (2-Ethylhexanol: 130.23 g/mol; Bis(2-ethylhexyl)carbonate: 286.45 g/mol; although the amount of the  2-ethylhexanol moiety in Bis(2-ethylhexyl) carbonate is 286.45 mg/mol, for recalculating the NOAEL of 2-Ethylhexanol to  Bis(2-ethylhexyl)carbonate twice the molecular weight of 2-Ethylhexanol (260.46 mg/mol) was used) and the release of 2 moles of 2-Ethylhexanol per mole of Bis(2-ethylhexyl)carbonate: 
NOAEL(maternal)=143 mg/kg bw/d; 
NOAEL(embryo-/fetotoxicity)=143 mg/kg bw/d; 
NOAEL(teratogenicity)=715 mg/kg bw/d 

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (groups of 10 instead of 20).

Qualifier:

according to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Version / remarks:

Cited as Directive 87/302/EEC, part B, p. 24

Deviations:

yes

Remarks:

10 animals per group instead of 20

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

10 animals per group instead of 20

GLP compliance:

yes

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, Biberach, Germany
- Age at study initiation: 68-85
- Weight at study initiation: 214-233
- Fasting period before study: no data
- Housing: singly, in stainless steel wire-mesh cages
- Diet: Kliba feed 343 ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Aqueous emulsions for gavage were freshly prepared every day under rapid stirring in doubly distileld water containing approx. 0.005% Cromophor EL

DIET PREPARATION
- Rate of preparation of diet (frequency): n.a
- Mixing appropriate amounts with (Type of food): n.a.
- Storage temperature of food: n.a.


VEHICLE
- Justification for use and choice of vehicle (if other than water): surfactant
- Concentration in vehicle:
- Amount of vehicle (if gavage): 0.005%
- Lot/batch no. (if required): no data
- Purity: no data

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatography was used to verify test concentrations and stability during a 6-hr storage

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1 to 1:4
- Length of cohabitation: until successful
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

gestation day 6 through 15

Frequency of treatment:

daily

Duration of test:

20 days

Remarks:

Doses / Concentrations:
0 (water), 0 (vehicle), 130, 650, 1300 mg/kg day (in bidist. water containing 0.005% Cremophor EL)
Basis:
actual ingested

No. of animals per sex per dose:

10 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: equimolar doses of 6 different alcohols including 2-EH were trested at 0, 1, 5, and 10 mmol/kg bw.
- Rationale for animal assignment (if not random): random
- Other:

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily



DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule:

BODY WEIGHT: Yes
- Time schedule for examinations: throughout the study


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): n.a., gavage study
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes / No / No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): n.a., gavage study
- Time schedule for examinations:


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: uterus and ovaries, fetuses

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No data

Statistics:

Dunnett's test: food consumption, body weight data, uterus weight before opening, placental and fetal weights, number of corpora lutea, implantations, pre- and post implantationloses, resorptions, and live and dead fetuses.
Fisher's exact test: conception rate, mortality of the dams, all fetal findings

Indices:

No data published

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
1300 mg/kg bw/day: significant toxicity (discoloration of liver and lung; pronounced clinical symptoms (nasal discharge, salivation, CNS depression); reduced food consumption, body weight loss; 6 mortalities.
650 mg/kg bw/day: slight maternal toxicity
130 mg/kg bw/day: no effect

Dose descriptor:

NOAEL

Effect level:

130 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
1300 mg/kg bw/day: increased early resorptions, high postimplantation loss; fetal body weights markedly reduced; increased incidences of skeletal malformations, variations, and retardations.
650 mg/kg bw/day: slightly decreased fetal weight; increased number of fetuses with skeletal variations and retardations
130 mg/kg bw/day: no effect

Dose descriptor:

NOAEL

Effect level:

130 mg/kg bw/day

Basis for effect level:

other: embryotoxicity

Dose descriptor:

NOAEL

Effect level:

650 mg/kg bw/day

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

    
    

130 mg/kg dose group:
No adverse substance-related effects on dams or fetuses.

650 mg/kg dose group:
* maternal toxic effects
- 2 dams with piloerection
* embryo/fetotoxic effects
- slightly reduced mean fetal body weights
- increased frequency of fetuses with skeletal variations  
and retardations

1300 mg/kg dose group:
* maternal toxic effects
- markedly reduced food consumption during the whole  
treatment period (days 6-15 p.c.)
- distinctly reduced mean body weights (day 10 -20 p.c.)  
body weight loss during days 6-10 p.c. and reduced body  
body weight gains during days 10-15 p.c.; markedly reduced  
corrected body weight gain
- 6 animals found dead on days 9, 10 and 13 p.c.
- severe clinical sypmtoms like abdominal or lateral  
position, unsteady gait and apathy
- light brown-gray discoloration of the liver in the animals
  with intercurrent death; lund edema and emphysema in a   
few animals, and hemometra in 1 dam which showed vaginal  
hemorrage before death
- distinctly reduced mean uterus weight
* embryo/fetotoxic effects
- increased number of resorptions and consequently markedly 
  increased postimplantation loss
- markedly reduced mean fetal body weights
- one fetus with acaudia and atresia ani; increased  
incidence of fetuses with dilated renal pelvis and/or 
  hydroureter higher number of fetuses with skeletal 
  malformations, variations and retardations.




  
  





 

2 -EH: maternal and developmental toxicity (publication, table 5)


  

    

    
Dose levels (mg/kg bw/day)
  
  

    

    
0 (water)
    
0 (vehicle)
    
130
    
650
    
1300
  
  

    
No. pregnant dams
    
9
    
10
    
10
    
10
    
9
  
  

    
Fetuses and litters examined
    
124/9
    
146/10
    
130/10
    
127/9
    
28/2
  
  

    
Maternal deaths
    

    

    

    
1/10(a)
    
6/10
  
  

    
Pregnant at termination
    
9
    
10
    
10
    
10
    
9
  
  

    
Clinical signs
    

    

    

    
(+)
    
++
  
  

    
Body weight(g) day 0
    
231.5
    
230.8
    
229.6
    
225.5
    
235.6
  
  

    
Body weight (g) day 20
    
375.0
    
384.2
    
377.4
    
367.1
    
308.9**
  
  

    
Uterus weight (g)
    
77.7
    
82.2
    
72.2
    
75.9
    
32.9**
  
  

    
Corpora lutea /dam
    
16.1
    
16.0
    
15.4
    
15.7
    
15.3
  
  

    
Implantation sites/dam
    
15.0
    
15.7
    
13.6
    
14.8
    
14.8
  
  

    
Dams with viable fetuses
    
9
    
10
    
10
    
9
    
2
  
  

    
Postimplantation loss (%)
    
8.2
    
7.0
    
5.0
    
4.5
    
54.7**
  
  

    
Live fetuses/dam
    
13.8
    
14.6
    
13.0
    
14.1
    
14.0
  
  

    
Resorptions (total/early/dam)
    
1.2/1.1
    
1.1/1.0
    
0.6/0.5
    
0.7/0.2
    
7.8**/7.8**
  
  

    
Fetal weight (g)
    
3.80
    
3.82
    
3.80
    
3.44**
    
2.86**
  
  

    
No. (and %) of fetuses with malformations
    
1 (0.8)
    
2 (1.4)
    
3 (2.3)
    
7 (5.5) 
    
5** (17.9)
  
  

    
No. (and %) of litters with malformations (b)
    
1(11)
    
2(20)
    
3(30)
    
4(44)
    
2(100)
  
  

    
No. (and %) of fetuses with variations (b)
    
46 (37)
    
46 (32)
    
41(32)
    
49 (39)
    
20 (71)**
  
  

    
No. (and %) of litters with variations (b)
    
8(89)
    
10(100)
    
9(90)
    
8(89)
    
2(100)
  
  

    
No. (and %) of fetuses with retardations (b)
    
28(23)
    
38(26)
    
31(24)
    
51(40)
    
15(54)**
  
  

    
No. (and %) of litters with retardations (b)
    
8(89)
    
10(100)
    
8(80)
    
9(100)
    
2(100)
  




  (a) due to gavage error       (b) 
  percentage rounded



  **p0.01



  



   


2-EH: incidence (%) and type of fetal findings; selected data (publication, tabe 6)




  

    

    
Dose levels (mg/kg bw/day)
  
  

    

    
0 (water)
    
0 (vehicle)
    
130
    
650
    
1300
  
  

    
No. of fetuses and litters examined
    
124/9
    
146/10
    
130/10
    
127/9
    
28/2
  
  

    
Dilated renal pelvis
    
23 (6)
    
28 (9)
    
18 (8)
    
21 (7)
    
10 (2)
  
  

    
Hydroureter
    
1
    
3 (2)
    
2 (2)
    
1
    
3
  
  

    
Total skeletal variations
    
23 (7)
    
17 (6)
    
23 (8)
    
27 (7)
    
10 (2)
  
  

    
Total skeletal retardations
    
28 (8)
    
38 (10)
    
31 (8)
    
51 (9)
    
15 (2)
  


  






   






  

Conclusions:

Clear signs of developmental toxicity, but not teratogenicity, were seen in the absence of maternal toxicity.

Executive summary:

The developmental toxicity of 2 -EH was investigated in a OECD TG 414 study conducted according to OECD TG 414 and under GLP, but using low rat numbers (10 instead of 20 pregnant females). This invalidates the study to some extend, but it provides weight of evidence for the developmental toxicity endpoint.

Maternal toxicity was most severe at the high dose level and marginal at the intermediate dose level. At the low dose no maternal toxicity was noted. Therefore the NOAEL is 130 mg/kg/d for this endpoint under the conditions of this study.

Signs of embryo-/fetotoxicity were dose-dependently noted in dams showing signs of maternal toxicity at 650 and 1300 mg/kg/d. Therefore the NOAEL is 130 mg/kg/d for this endpoint under the conditions of this study.

Teratogenicity was noted in fetuses from the high dose dams only. Therefore the NOAEL is 650 mg/kg/d under the conditions of this study for teratogenicity.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

143 mg/kg bw/day

Study duration:

subacute

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

A developmental toxicity study in rat is available for the read-across substance 2-Ethylhexanol (2-EH). The read-across approach is justified based on metabolism.

As Bis(2-ethylhexyl) carbonate does not penetrate the skin (c.f. IUCLID entry Dermal absorption: 14858-73-2_8.8.1_THG_2007_OECD 428) and has a very low vapour pressure and a use pattern which will not generate inhalative exposure, the only route of exposure relevant for risk assessment is oral ingestion.

The organic branched chain carbonate Bis(2-ethylhexyl) carbonate is expected to be acid labile and thus will break down to its carbonate and alcohol moieties at contact with the acidic gastric juice. The resulting carbonic acid, respectively the carbonate anion and carbon dioxide are uncritical from a toxicological view due to natural regulation mechanisms.

The released alcohol moiety 2-Ethylhexanol might be systemically absorbed and thus might have a systemic effect and is therefore the relevant substance for read across. To justify this read across approach, the postulated gastric break down was experimentally verified in an in vitro hydrolysis study. The results of this hydrolysis study showed a hydrolysis of Bis(2-ethylhexyl) carbonate of about 65% within 4 hours ingastric-fluid simulant and a hydrolysis of about 15% within 4 hours in intestinal-fluid simulant. Enzymes capable of hydrolysing Bis(2-ethylhexyl) carbonate are present in the gastrointestinal tract, and thus Bis(2-ethylhexyl) carbonate will start to be metabolised prior to absorption.

As the substance is expected to hydrolyse rapidly in vivo, the parent substance is unlikely to reach the reproductive organs. Any systemic effects are expected to be due to the metabolite 2-Ethylhexanol. Moreover, in the available genetic toxicity tests, no indications for mutagenic potential or for the generation of any reactive metabolites of Bis(2-ethylhexyl) carbonate were found.

 

The developmental toxicity of 2-Ethylhexanol was investigated in a study conducted according to OECD TG 414 and under GLP, but using low rat numbers (10 instead of 20 pregnant females).

The test item was administered to 10 Wistar rats by oral gavage at dose levels of 0, 130, 650, 1300 mg/kg bw/day daily from gestation day 6 through 15.

At 1300 mg/kg bw/d significant toxicity (discoloration of liver and lung; pronounced clinical symptoms (nasal discharge, salivation, CNS depression), reduced food consumption, body weight loss were noted in the dams; 6 animals died. At 650 mg/kg bw/day only slight maternal toxicity was observed. No maternal toxicity was noted at 130 mg/kg bw/d.

At 1300 mg/kg bw/d increased early resorptions, high postimplantation loss; markedly reduced fetal body weights, increased incidences of skeletal malformations, variations, and retardations were observed. At 650 mg/kg bw/d slightly decreased fetal weight, increased number of fetuses with skeletal variations and retardations were noted. No embryotoxic effects were observed at 130 mg/kg bw/d.

Maternal toxicitywas most severe at the high dose level and marginal at the intermediate dose level. At the low dose no maternal toxicity was noted. Therefore the NOAEL is 130 mg/kg bw/d for this endpoint under the conditions of this study.

Signs of embryo-/fetotoxicity were dose-dependently noted in dams showing signs of maternal toxicity at 650 and 1300 mg/kg bw/d. Therefore the NOAEL is 130 mg/kg bw/d for this endpoint under the conditions of this study.

Teratogenicity was noted in fetuses from the high dose dams only. Therefore the NOAEL is 650 mg/kg bw/d under the conditions of this study for teratogenicity.

Recalculation based on molecular weight (2-Ethylhexanol: 130.23 g/mol; Bis(2-ethylhexyl) carbonate: 286.45 g/mol) and the release of 2 moles of 2-Ethylhexanol per mole of Bis(2-ethylhexyl) carbonate resulted in a NOAEL(maternal toxicity) of 143 mg/kg bw/d, a NOAEL(embryo-/fetotoxicity) of 143 mg/kg bw/d and a NOAEL(teratogenicity) of 715 mg/kg bw/d for Bis(2-ethylhexyl) carbonate. (Although the amount of the 2-ethylhexanol moiety in Bis(2 -ethylhexyl) carbonate is 286.45 mg/mol, for recalculating the NOAEL of 2-Ethylhexanol to Bis(2-ethylhexyl)carbonate twice the molecular weight of 2-Ethylhexanol (260.46 mg/mol) was used.)

There are no data gaps for the endpoint developmental toxicity. No human data are available. However, there is no reason to believe that these results from rat would not be applicable to humans.

Justification for selection of Effect on developmental toxicity: via oral route:
OECD guideline 414 study, 10 females instead of 20, GLP

Justification for classification or non-classification

Based on the available data, Bis(2-ethylhexyl) carbonate does not need to be classified for toxicity to reproduction, developmental toxicity and teratogenicity according to the criteria given in regulation (EC) 1272/2008 or the former European directive on classification and labelling 67/548/EEC. Thus, no labelling is required.