Dosing solutions concentrations were checked for degradation over the time period of the study and doses were calculated based on these measurements.

BBP from Aldrich (98% purity). The sample used was confirmed to possess the expected activity and potency in the yeast human estrogen receptor (ERa) transactivation assay described by Routledge and Sumpter (1996; J Sumpter, personal communication; data not provided).

Fresh stock solutions were prepared every 48/72 hr and stored in Pyrex glass bottles.

Stock solutions of BBP were assessed for stability in plastic and Pyrex glass bottles using liquid chromatography linked to mass spectrometry (Finnigan MAT TSQ 7000 machine). A reverse-phase in human sperm quality and sperm counts in some C8 column was used with a mobile phase of water locations (Sharpe, 1993). Duplicate measurements were made 2 hr and 1, 2, and 6 days after preparation of the solutions.

No internal measure of dose.

Same dosing method and time frame used for all groups.

Ashby et al. 1997

Risk of bias

Animal bioassay experiments

HAWC