The toxicity of a commercial preparation of polybrominated biphenyl was determined in 24 pregnant Holstein heifers that were alloted randomly to one of four experimental groups given 0 (I), .25 (II), 250 (III), and 25,000 (IV) mg per day of fireMaster BP-6 for 60 days or until the animals became moribund. Clinicopathologic determinations were on day -1 prior to dosing, days 15, 30 and 60 during dosing, and following dosing on days 80, 110, 150, and 190 from start of dosing. In addition, samples were collected from moribund heifers of Group IV immediately prior to necropsy. Toxicity was not evident in heifers in Groups I, II, or III. Toxicity was induced in heifers in Group IV. Glutamic-oxaloacetic transaminase of serum was increased and calcium decreased as early as day 15 whereas significant increases in lactate dehydrogenase, urea nitrogen, and bilirubin, and decreases in albumin were not observed until day 30 in heifers of Group IV. Analysis of urine from moribund heifers of Group IV revealed moderate proteinuria and decreased specific gravity. Evaluation of clinicopathologic data has suggested that the polybrominated biphenyls fed were renal toxins with no clear evidence of hepatotoxicity.

The toxicity of a commercial blend of polybrominated biphenyls was determined in 24 pregnant Holstein heifers that were allotted randomly to one of four experimental groups given 0, .25, 250, or 25,000 mg/day of fire-Master BP-6. The polybrominated biphenyls were mixed with finely ground corn and given by bolus for 60 days or until the animal became moribund. Average body weight of heifers at onset of experiment was 381 kg. No clinical signs of toxicosis were evident in heifers fed 0, .25 or 250 mg/day. Toxicosis was induced in heifers fed 25,000 mg/day resulting in reduced dry matter intake, body weight, heart rate, and respiration rate. Clinical signs were anorexia, emaciation, dehydration, excessive lacrimation and salivation, diarrhea, depression, and abortion or fetal death. All heifers fed 25,000 mg/day became moribund within 33 to 66 days.

A rapid method was developed for the extraction, isolation, and detection of polybrominated biphenyls (PBBs) from plasma, feces, milk, and bile, using disposable glassware. Use of disposable equipment greatly reduced the amount of laboratory background and cross-contamination of samples. The procedure employed a multiple extraction with a mixture of diethyl and petroleum ethers, followed by cleanup on miniature Florisil, silica gel, and sodium sulfate columns. Detection was accomplished by gas chromatography. Recoveries were determined for the six major components of a commercial PBB mixture and were approximately 96% for plasma, 59% for feces, and 98% for milk. The background levels for plasma, feces, and milk were 0.0005, 0.0007, and 0.0007 ppm, respectively, bringing the minimum detectable limits of the major hexabromobiphenyl peak to 0.0010, 0.0014, and 0.0014 ppm on a whole tissue basis.