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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
other: handbook data
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: A non GLP compliant study with little information on methodology or guidelines followed.

Data source

Reference
Reference Type:
publication
Title:
The Effects of Metals on the Chick Embryo: Toxicity and Production of Abnormalities in Development
Author:
Ridgeway L & Karnofsky D
Year:
1952
Bibliographic source:
Annals New York Academy of Sciences Pg. 203 - 215

Materials and methods

Test guideline
Qualifier:
no guideline followed
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
other: Chick embryo
Strain:
other: White Leghorn eggs
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Commercial supplier
- Age at study initiation: Embryo's were injected at either 4 or 8 days old

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Room temperature

Embroys were kept in incubation from study initiation to day 18, then all embryos were sacrificed.

Administration / exposure

Route of administration:
other: injection into 1 of 2 sites: yolk or CAM (chorioallantoic membrane)
Vehicle:
water
Details on exposure:
Injection volume - 0.05 -0.2 cc (cm³); occasionally yolks were injected with 0.3-0.4 cc (cm³)

Injection route - yolk at day 4; chorioallantoic membrane at day 8

Injection route preparation -
Yolk - a hole was drilled in the blunt end of the egg, the opening was sealed after exposure with melted paraffin.
CAM - a small window was cut in the shell directly over the membrane, post exposure the opening was sealed with Scotch tape.

Sample size - 6 - 10 eggs were injected at several dose levels either side of the estimated LD50.
Analytical verification of doses or concentrations:
not specified
Frequency of treatment:
single dose
Details on study design:
Preliminary test:
Preliminary tests were performed on the 4 day embryo yolk sacs to identify an approximate LD50, then more precise testing was carried out to determine an accurate figure for the LD50.

The information from the preliminary test for yolk sacs was used to establish a staring point for the 8 day chorioallantoic membrane toxicity tests.

Observations:
Embryos were candled daily until the 18th day of incubation with dead embryos removed and examined. Occasionally embryos were sacrificed due to incubation reasons. All remaining embryos were sacrificed at day 18.

The following observations were recorded: abnormalities in skin, feathers, bone, brain and internal organs, The membranes and yolk were also inspected.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:not examined

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no data

Details on embryotoxic / teratogenic effects:
The information on embryonic abnormalities or effects is not available for tantalum.

Effect levels (fetuses)

open allclose all
Dose descriptor:
other: LD50
Effect level:
ca. 20 other: Mgs/egg
Based on:
test mat.
Basis for effect level:
other: embryotoxicity
Dose descriptor:
other: LD50
Effect level:
ca. 36 other: (Microatoms/egg)
Based on:
test mat.
Basis for effect level:
other: embryotoxicity
Dose descriptor:
other: LD50
Effect level:
ca. 6.4 other: (Microatoms/egg)
Based on:
test mat.
Basis for effect level:
other: embryotoxicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Under the conditions of the test, the 4 day LD50 value of the test material when injected into the yolk was determined to be 20 mgs/egg. Additional LD 50 values were determined to be 51 microatoms/egg (4 day yolk), 36 microatoms/egg (8 day yolk) and 6.4 microatoms/egg (8 day chorioallantoic membrane(CAM)). The test material was shown to be more toxic to an embryo when injected into the CAM in comparison to exposure via the yolk.
Executive summary:

Under the conditions of the test, the 4 day LD50 value of the test material when injected into the yolk was determined to be 20 mgs/egg. Additional LD 50 values were determined to be 51 microatoms/egg (4 day yolk), 36 microatoms/egg (8 day yolk) and 6.4 microatoms/egg (8 day chorioallantoic membrane(CAM)). The test material was shown to be more toxic to an embryo when injected into the CAM in comparison to exposure via the yolk. No information was given about any abnormalities or observations made during the study.