Dibutyl phthalate

Toxicity to birds

Administrative data

Endpoint:

toxicity to birds, other

Remarks:

short-term: effects on eggs

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1974

Materials and methods

Principles of method if other than guideline:

No guideline specified, cf. "Any other information on material and methods" for details.

GLP compliance:

not specified

Test material

Test material information

Specific details on test material used for the study:

Phthalates were kindly provided by the Monsanto Chemical Company.

Dose method:

feed

Test organisms

Test organisms (species):

other: Streptopelia risoria

Study design

Total exposure duration (if not single dose):

48 h

Control animals:

yes

Results and discussion

Any other information on results incl. tables

The most significant findings were that eggshell thickness was decreased and permeability to water increased by a diet containing 10 ppm d-n-butyl phthalate (Table 1). In contrast, no significant effect

was found with di-2-ethylhexyl phthalate. The rate of water loss increased by 23% whereas the decrease in eggshell thickness was only 10%. It was noted that small dents occurred rather frequently

in eggs from birds treated with DNBP. While damaged eggs were excluded from those used for the calculation of water loss and permeability, micro-damage to the eggshell may have been the cause of'

increased water loss. The experiments on the breaking strength of the egg were unsatisfactory, due to the fact that the low values (0.5-1.0 lb) are at the low end of the range of the Instron Testing machine used. Damage to the surface, rather than hairline cracks, was observed and breaking strength correlated poorly with shell index. Structurally, the main differences appear to be the presence of more fibrous materials in the eggshell (Figure 1) compared to control eggs. The size and distribution of pores appear-to be unaffected despite the considerable increase in permeability. The effect of DNBP thus has considerable differences from DDE where decreased numbers of pores are observed (PEAKALL et al. 1973), permeability is decreased, and cracking is more common than denting.

Applicant's summary and conclusion

Conclusions:

Eggshell thickness was decreased and permeability to water increased by a diet containing 10 ppm d-n-butyl phthalate.

Executive summary:

In this study the effects of a diet of 10 ppm DNBP and 10 ppm DEHP on eggshell thickness, breaking strength, permeability, and shell structure of the eggs of Ring Doves

(Streptopelia risoria) were examined.