The leachability of both Di(2-ethylhexyl)
phthalate (
DEHP) and Tri(2-ethylhexyl) trimellitate (TEHTM) or
Trioctyl trimellitate (
TOTM) from haemodialysis tubing was investigated in 20 patients with
chronic renal failure undergoing maintenance haemodialysis. The blood tubing made of common
polyvinyl chloride (
PVC) plasticized with
DEHP (group 1 patients) were replaced with tubing plasticized with
TOTM-
DEHP (group 2 patients). The patient blood obtained from the inlet and the outlet of the dialyzer was analyzed during a 4 h-dialysis session. Thus, the circulating concentrations of both
DEHP and
TOTM resulting from the release from dialyzer tubes were estimated using High-performance Liquid chromatograph (HPLC). With the common
PVC-
DEHP blood tubing, a
DEHP quantity of 122.95+/-33.94 mg was extracted from tubing during a single dialysis session (ranging from 55 to 166.21 mg). During the same period, the total amounts of
DEHP retained by the patients were 27.30+/-9.22 mg (ranging from 12.50 to 42.72 mg). As for blood tubing plasticized with
TOTM-
DEHP, 41.80+/-4.47 mg of
DEHP and 75.11+/-25.72 mg of
TOTM were extracted. During the same period, the amounts of
DEHP and
TOTM retained by the patients were 3.42+/-1.37 mg and 4.87+/-2.60 mg, respectively. The extraction rate both
plasticizers was correlated with serum
lipid content (cholesterol+triglyceride) (r(2)=0.75 for
DEHP and r(2)=0.64 for
TOTM). In the present investigation, less
TOTM and
DEHP were apparently released from haemodialysis tubing plasticized with
TOTM-
DEHP than
DEHP released from haemodialysis tubing plasticized with
DEHP only.
TOTM seems to be a superior alternative to
DEHP for use in medical devices because of its potential lower leachability. To recommend it as an alternative
plasticizer, its possible toxicity towards human body should be investigated before it can be used routinely. However, patients undergoing haemodialysis using tubing plasticized with
DEHP only are regularly exposed to non negligible amounts of
DEHP. In view of several
biological effects previously reported, it is time to reconsider the use of
DEHP only as a
plasticizer.