Acute, subacute, and residual effects of polychlorinated biphenyl (PCB) in rats. I. Biologic half‐life in adipose tissue

Sprague‐Dawley rats were fed diets containing Aroclor 1254 at 0, 5, 50, or 500 ppm for 4 wk. The biologic half‐life of Aroclor 1254 in adipose tissue of rats fed 500 ppm, as determined by a gas chromatographic method, was 8 wk in males and 12 wk in females. These results are in line with sex‐linked differences reported previously for other chlorinated hydrocarbons. It appears that the lower chlorine homologs in the Aroclor mixture are metabolized while those with higher chlorine content are lost more slowly.