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EC number: 249-636-2 | CAS number: 29450-45-1
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Developmental toxicity / teratogenicity
Administrative data
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 12.09.1991 - 10.10.1991
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Cross-reference
- Reason / purpose for cross-reference:
- read-across source
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 991
- Report date:
- 1991
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 414 (Prenatal Developmental Toxicity Study)
- GLP compliance:
- yes (incl. QA statement)
Test material
- Reference substance name:
- (4-chloro-2-methylphenoxy)acetic acid
- EC Number:
- 202-360-6
- EC Name:
- (4-chloro-2-methylphenoxy)acetic acid
- Cas Number:
- 94-74-6
- Molecular formula:
- C9H9ClO3
- IUPAC Name:
- (4-chloro-2-methylphenoxy)acetic acid
- Test material form:
- liquid
- Details on test material:
- pH = 10.9
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Wistar
- Details on test animals or test system and environmental conditions:
- Animals:
Healthy young adult virgin femeles strain Wistar were used. The females aged 3 months. At the start of the study there average weight was 218 t 19g. They came from the Central Experimental Animals Farm, Silesian Medical Academy in Katowice. The males were from the same farm in the same condition. 20 pregnant females per each group were used.
Housing
The animals were caged in plast-metalic cages with UV-sterilized wood spruces in one experimental room. On each cage was a shield with cod of the experiment, cage number, number of animal, start and finish date of study, dose and eventually date of death.
Feeding
Conventional laboratory food for rodents "Murigran" and drinking water were supplied unlimited. Toxic impurities (heavy metals, aflatoxin, nitrosamines) in food were determined. All values were under the FDA - limits.
Administration / exposure
- Route of administration:
- oral: gavage
- Details on exposure:
- Dose levels
Doses were chosen on the basis of the sub-chronic, chronic and embriotoxic/teratogenic values. In a pilot study in the doses 250 mg/kg b. w. 8 from 9 tested females died in the days 11 – 15 of the experiment, Three followed doses of MCPA were determined: 0.5, 5 and 50 mg/kg b. w. A control group received only water. The volume of the applied solution was constant , a 1 ml per 100 g of b.w.
Results and discussion
Results: maternal animals
Effect levels (maternal animals)
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 50 mg/kg bw/day
- Based on:
- test mat.
- Basis for effect level:
- body weight and weight gain
- food consumption and compound intake
Results (fetuses)
Effect levels (fetuses)
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 50 mg/kg bw/day
- Based on:
- test mat.
- Sex:
- female
- Basis for effect level:
- fetal/pup body weight changes
- changes in litter size and weights
- external malformations
- skeletal malformations
Overall developmental toxicity
- Key result
- Developmental effects observed:
- no
Any other information on results incl. tables
Results
At a pilot doses 250 mg/kg a bight death rate of the females (8/9) was noted. By this reason this doses cannot be evaluated. In the remaining doses during the whole experiment time the females were in good form without any toxic signs in the control as well as in the treated groups. Only in the dose 50 mg/kg b.w. temporarily there was observed a lower motility and distinctly reaction on external impulses. No statistically significant differences were noted between the controls and the intoxicated groups in food consumption (Tab. 1) and body weight (Tab.2)
Table No 1 Food intake (gram/rat/day)
Day of pregnancy |
Dose (mg/kg b. w.) |
|||
Control |
0.5 |
5.0 |
50.0 |
|
5 |
21.2 ± 3.5 |
20.8±3.6 |
21.9±32 |
21.7±19 |
10 |
20.9 ± 1.8 |
22.4±2.0 |
21.3±2.4 |
20.0±18 |
15 |
22.5 ± 2.0 |
22.7±2.8 |
22.5±2.0 |
21.0±27 |
20 |
24.5 ± 1.8 |
25.1± 2.9 |
24.1±3.1 |
22.7±28 |
Table No 2 MCPA - Body weight of females (g)
Day of |
Dose (mg/Kg b.w.) |
|||
|
|
|||
pregnancy |
Control |
0.5 |
5.0 |
50.0 |
1 |
214±21 |
221±19 |
214±20 |
223±17 |
6 |
237±23 |
244±20 |
237±20 |
246±19 |
7 |
238±23 |
246±20 |
238±20 |
247±17 |
8 |
243±24 |
250±21 |
242±20 |
252±19 |
9 |
246±23 |
253±20 |
245±20 |
254±18 |
10 |
247±23 |
253±19 |
246±21 |
254±19 |
11 |
254±24 |
259±18 |
256±20 |
260±18 |
12 |
255±25 |
261±19 |
255±21 |
262±18 |
13 |
263±25 |
267±19 |
261±21 |
266±18 |
14 |
264±25 |
270±18 |
266±22 |
270±19 |
15 |
276±30 |
274±19 |
270±23 |
276±20 |
20 |
328±27 |
331±24 |
326±28 |
329±24 |
The number of fetuses obtained from 20 females in the control and each intoxicated group were similar. Also the average number of fetuses in one litter in all groups was similar. All fetuses were alive. No anomaly were stated. The number of resorpations per one female differ from 0 to 2 in all groups but the average number was 0.25 – 0.45 in the in toxicated groups and 0.05 in the control.
But the values are in the range of the physiological norm for this strain. The average number of corpus luteum was similar in each group, The data are listed in table 3.
Table no 3 Number of corpus luteum, fetuses and resorptions
Dose mg/Kg bw |
Number of females |
Number of |
Number of fetuses |
Number of resorptions |
|||||
Sum |
in one |
Average in |
Anomaly |
Sum |
in one |
Average |
|||
Control |
20 |
10.9±1.6 |
218 |
8 - 13 |
10.9 ± 1. 5 |
0 |
1 |
0 - 1 |
0.05 |
0.5 |
20 |
11.3 ± 2.7 |
222 |
5 - 16 |
11.1 ± 2.8 |
0 |
5 |
0 - 1 |
0.25 |
5.0 |
20 |
11.3 ± 1. 5 |
217 |
7 - 14 |
10. 8 ± 1. 9 |
0 |
9 |
0 - 2 |
0.45 |
50.0 |
20 |
11.3± 2.3 |
221 |
6 - 14 |
11. 0 ± 2. 5 |
0 |
7 |
0 - 2 |
0.35 |
The weight of fetuses with the placenta and amnostic fluids and without placenta were similar in the control and in the doses 0.5 and 50 mg/kg. But in the dose 5 mg/kg b.w. this parameters was significantly higher. But this results are not dose - respondent. The length of the fetuses with the tails and without the tails in the intoxicated groups differ not from the control, This data are given in table 4.
Table no 4 Weight of fetuses and placenta and length of fetuses
Dosis mg/Kg b.w. |
Number of fetuses |
weight of fetuses (mg) |
Length of fetuses (mm) |
||
with placenta |
without placenta |
with tail |
without |
||
|
|||||
Control |
218 |
4610 ± 176 |
3272 ± 238 |
50.0 ± 0.8 |
37.6 ± 0.7 |
0.5 |
222 |
4771 ± 337 |
3344 ± 224 |
50.7 ± 0.9 |
38.1 ± 1.0 |
5.0 |
217 |
4868 ± 235 |
3484 ± 228 |
51.3 ± 1.3 |
38.3 ± 0.9 |
50.0 |
221 |
4684 ± 240 |
3408 ± 250 |
51.0 ± 1.4 |
38.0 ± 0.9 |
The macroscopic findings in the fetuses were not significant, The body integuments, the legs, the conchaes of auricle, nares, eyelids and oral cavities were well developed.
After sagittal section the exanimated soft tissues of the fetuses were well developed and normally located in the body cavities. There were no differences between the control and the exposed groups. The percentage of ossification points of the sternum in the intoxicated groups, regardless of the dose, did not differ significantly from the control (Tab, 5 and 7),
Table no. 5 number of ossification points of sternum (X)
Dosis mg/kg b.w. |
Number of fetuses |
|
Humber of ossification points |
|||
4 |
|
5 |
6 |
7 |
||
Control |
112 |
100. |
0 |
97.3 |
79.5 |
3.6 |
0.5 |
115 |
100. |
0 |
99.1 |
87.8 |
0.0 |
5.0 |
113 |
100. |
0 |
99.1 |
90.3 |
0.9 |
50.0 |
114 |
100. |
0 |
100.0 |
86.0 |
1.7 |
Table no 6 Number of ossification points of legs (X)
Dosis
mg/Kg b.w. |
limber of fetuses |
Humber of ossification points |
||||
Fore leg |
Hind leg |
|||||
3 |
4 |
3 |
4 |
5 |
||
Control |
112 |
100 |
45.5 |
100 |
100.0 |
0.0 |
0.5 |
115 |
100 |
70.4 |
100 |
97.4 |
0.9 |
5.0 |
113 |
100 |
81.4 |
100 |
100.0 |
0.9 |
50.0 |
114 |
100 |
87.7 |
100 |
100.0 |
0.0 |
The same is true for the ossification of the metacarpus and metacarpus (Tab 6 and 7).
Table no 7 Average number of ossification sternum and legs
Dosis
mg/kg b.w. |
Number of fetuses |
Sternum |
Metacarpus |
Metatarsus |
Control |
112 |
5.9 ± 0.3 |
3.5 ± 0. 3 |
4.0 ± 0.0 |
0.5 |
115 |
5.9 ± 0.2 |
3.7 ± 0.3 |
4.0 ± 0.1 |
5.0 |
113 |
5.9 ± 0.2 |
3.8 ± 0.3 |
4.0 ± 0.0 |
50.0 |
114 |
5.9 ± 0. 2 |
3.9 ± 0.2 |
4.0 ± 0.0 |
The ossifications of the skull, axial skeleton, ribs, scapular and pelvis region with legs were well developed and did not differ between the treated groups and the control.
Applicant's summary and conclusion
- Conclusions:
- It was stated that MCPA in doses till 50 mg/Kg b.w, has no embriotoxic and teratogenic effects on the rats fetuses.
MCPA in a dose of 250 mg/kg b.w. was very toxic for the pregnant females - Executive summary:
MCPA in the form of soluble concentrate was applied to young healthy female rats strain Wistar orally by a gevage daily in the 6 - 15 day of pregnancy. Three groups consisting of 20 pregnant females each received MCPA (Chwastox extra) diluted with water in doses 0.5, 5 and 50 mg/Kg b. w. The control received only water. Females in all groups survived the pregnant period without any toxic effect. One day before the expected birth the females were sacrificed and the following parameters were examined: number of implantation sides, resorpations and corpora lutes, number of dead, living and malformed fetuses, their weight, length and external look. One - half of each litter was prepared for examination for skeletal deformations. The remained fetuses were fixed in Bouen solution for soft tissue examination.
It was stated that MCPA in doses till 50 mg/Kg b.w, has no embriotoxic and teratogenic effects on the rats fetuses.
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