Diphenyl ether

Toxicity to other aquatic organisms

Administrative data

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1983

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: No GLP information, documentation insufficient for assessment and unsuitable test system.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1983

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Conducted according to:
Pagano G, Esposito A, Giordano GG: Fertilization and larval development in sea urchins following exposure of gametes and embryos to cadmium. Arch Environ Contam Toxicol 11:47-55, 1982.

Pagano G, Esposito A, Bove P, deAngelis M, Rota A, Vamvakinos E, Giordano GG: Arsenicinduced developmental defects and mitotic abnormalities in sea urchin development. Mutat Res

Pagano G, Esposito A, Bove P, deAngelis M, Rota A, Giordano GG: The effects of hexavalent and trivalent chromium on fertilization and development in sea urchins. Environ Res 30:442-452, 1983

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Diphenyl ether

EC Number:

202-981-2

EC Name:

Diphenyl ether

Cas Number:

101-84-8

Molecular formula:

C12H10O

IUPAC Name:

phenoxybenzene

Details on test material:

Source: Merck, West Germany

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

other: Sea urchins- Paracentrotus lividus and Sphaerechinus granularis

Study design

Test type:

not specified

Water media type:

saltwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Zygotes and embryos- up to 48 hrs, sperm- no data and eggs- 5 or 10 minutes

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

other: teratogenic actions

Effect conc.:

>= 2 other: ppm

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: developmental defects and mitotic abnormalities

Remarks on result:

other: Exposure duration: Zygotes and embryos- up to 48 hrs, sperm- no data and eggs- 5 or 10 minutes

Any other information on results incl. tables

Preliminary experiments ruled out any evident action of the intermediate solvents (DMSO, DEE, E) on embryogenesis even at concentrations above 1 0/00, ie, the level commonly adopted in the experiments. DPE was effective in inducing developmental abnormalities in S granularis, following the different treatment schedules (minimal active levels:e-6 M for DPE). P Zividus embryos and gametes appeared to be somewhat more resistant than S granularis (minimal active levels:e-5 M for DPE). In both species, however, the exposure of embryos mainly resulted in pathologic, mesenchyme-filled blastulae, exogastrulae, up to prehatching blockage. Along with the induction of developmental defects, mitotic activity in DPE-exposed embryos was affected quantitatively and morphologically in both species. The changes in mitotic patterns from a control P Zividus cleaving embryo (~ 125-c) to heavily affected DPE-exposed (9 e-5 M) embryos, displaying an impairment of cleavage and abnormal, highly hyperchromic mitotic figures. The quantitative alterations of mitotic activity in P lividus, following exposure to DPE were reported, showing a dose-response decrease in the number of mitoses per embryo (MPE), consistently associated with an increase in interphase embryos (IE). Mitotic abnormalities, though evident, did not display a consistent dose-response trend, possibly owing to the mitotic blockage at the highest DPE level. The exposure of sperm, in both species, resulted in a depression of the fertilizing capacity and in an increase of developmental and mitotic abnormalities. These effects also displayed a greater effectiveness of DPE, as compared to DP. Data showed the inactivation patterns of S granularis sperm, following exposure to DPE. A figure showed the induction of larval malformations following exposure of P lividus sperm, resulting in embryonic lethality, at the highest DPE (9 x e-5 M) levels. An example of developmental abnormality, where skeletal malformation is dramatically affecting pluteus arms was presented. A decrease in MPE and a concomitant increase in IE (both reflecting a loss in mitotic activity) were observed, similarly to the results of embryo exposure. The increase in mitotic abnormalities, with the appearance of free chromosomes and asymmetrical mitotic figures, was evident at the highest DPE level (~ e-4 M).

I.) Induction of Developmental Defects Following Exposure of S granulari's Embryos or Gametes to DPE. P lividus Displayed Widely Overlapping Results:

Treatment:Control Cleavage (125-c)(5 h after fertilization); Gastrulae(24 h after fertilization); Plutei (48 h after fertilization)

Treatment: e-5 M DPE

Embryos: Abnormal/blocked cleavage (5 h after fertilization) Filled blastulae; Cell Separation (24 h after fertilization) Indifferentiated blastulae; exogastrulae (48 h after fertilization)

Sperm: --- (5 h after fertilization); Indifferentiated or filled blastulae(24 h after fertilization); Loss of motility; cytolysis (48 h after fertilization)

Eggs: Early cytolysis; abnormal cleavage(5 h after fertilization); Cytolysis; pathologic survivors (24 h after fertilization); Cytolysis (48 h after fertilization)

II.) Sperm Inactivation Experiment: Decrease in Fertilization Rate (FR) Induced by Prolonged Exposure of S granularis Sperm to DPE (Mean of Two Experiments:

FR +/- SE)

Control (1 0/00 DMSO): 95 +/- 0.5, 85 +/- 4, 56 +/- 6, 9 +/- 3 and 1+/- 0.5 following sperm exposure for 2, 5, 10, 30 and 40 min,. respectively.

e-5M DPE: 86 +/- 3, 59 +/- 1, 9 +/- 2, 1 +/- 0.5 and 0.5 +/- 0.5 following sperm exposure for 2, 5, 10, 30 and 40 min,. respectively.

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Diphenyl ether was most effective on sea urchin embryos and gametes, by inducing developmental and mitotic abnormalities.

Executive summary:

This study was designed to investigate the possible genotoxic and teratogenic actions of diphenyl (DP), diphenyl ether (DPE), and their eutectic mixture, in a comparative approach including different test systems. Two microbial systems and a metazoan model were used: (1) diploid D7 strain of Saccharomyces cerevisiae; (2) Salmonella typhimurium strains TA100, TA98, TA1535, TA1537, TA1538, TA1532, TA2636; and (3) sea urchins (Paracentrotus lividus and Sphearechinus granularis).

Both compounds resulted in severe toxicity in all of test organisms at levels >/= e-5 M ( ~ 2 ppm). DP caused genetic effects in yeast with and without activating system, while the two chemicals appeared to be ineffective in Salmonella up to toxic levels. The action of DP and DPE on sea urchins resulted in developmental defects and mitotic abnormalities, following exposure of embryos or by pretreatment of sperm or eggs. In this system DPE appeared to be more effective than DP by about one order of magnitude (minimal active concentrations: e-5 M vs e-4 M).

The eutectic mixture, industrially used as a heat transfer medium, was tested in its virgin and used form, for genotoxicity and embryotoxicity. The latter appeared to be more effective than the virgin eutectic. This increase in the embryoand genotoxicity of the used eutectic may be related to the appearance of newly formed compounds in the heat transfer process. These compounds have been separated by high-pressure liquid chromatography and detected by fluorimetry.