Di(2-ethylhexyl) Phthalate Migration Research Articles

Reducing the migration of di-2-ethylhexyl phthalate from polyvinyl chloride medical devices

We attempted to determine the processing conditions for decreasing the migration of phthalate esters, particularly di-2-ethylhexyl phthalate (DEHP), from polyvinyl chloride (PVC) products using a drug solvent after dilution based on the package insert. PVC sheets and PVC tubing were subjected to optical irradiation (ultraviolet (UV), visible light irradiation) and heat treatment to determine whether they are deteriorated by these treatments. UV irradiation to one side of the PVC sheet decreased the levels of DEHP migration from the sheets by almost 50%, although the amount of DEHP content in PVC sheet was observed no significant change. On the other hand, the levels of DEHP migrating from the inner surface of PVC tubing UV-irradiated from the outer surface were not decreased compared with the control. Therefore, the surface structure was examined by conducting Fourier transform infrared spectroscopy (FT-IR), electron spectroscopy for chemical analysis (ESCA) and static angle of contact measurement. In FT-IR analysis, we found that the UV-irradiated PVC sheets were exhibited broadened absorption bands with time. In ESCA analysis, the chlorine content was decreased and the oxygen content was increased with time in UV-irradiated PVC sheets. Moreover, the other treated PVC sheets shows no significant change compared with the non-UV-irradiated PVC sheet. Therefore, the surface structure of the UV-irradiated PVC sheet was changed. As a result, the migration of DEHP from PVC products can be decreased with simple treatment, such as UV-irradiation. This could be a useful method to develop novel PVC products.

High-throughput determination of mono- and di(2-ethylhexyl)phthalate migration from PVC tubing to drugs using liquid chromatography–tandem mass spectrometry

The risk assessment of di(2-ethylhexyl) phthalate (DEHP) that migrated from polyvinyl chloride (PVC) medical devices is an important issue for hospitalized patients. Many studies have been conducted to determine the level of DEHP migration. A recent report has indicated that DEHP in blood bags was hydrolyzed by esterase to mono(2-ethylhexyl) phthalate (MEHP). Therefore, a method for the simultaneous determination of DEHP and MEHP was developed. The migration of DEHP and MEHP from PVC tubing to drugs was examined. Although we detected MEHP in the drugs, we found no enzymatic activity involved in the migration process. Some reports have indicated that hydrolysis may have occurred during sterilization by autoclaving. However, we did not perform any heat treatment. It is speculated that the MEHP migrated directly from the PVC tubing. The simultaneous determination of DEHP and MEHP is required for risk assessment, as MEHP may be even more toxic than the parent compound.

DEHP Migration Behavior from Excessively Plasticized PVC Sheets

The quantity, process and kinetics of di-(2-ethylhexyl)phthalate (DEHP) migration in the 30/70 and 40/60 poly(vinylchloride) (PVC)/DEHP blends were investigated using gas chromatograph. A thin and flexible PVC sheet was soaked in surrounding medium (SM) of water/ethanol mixture and acetonitrile with constant stirring to release DEHP. By observed concentration of DEHP in the SM, it is found that acetonitrile is more intense in DEHP migration than water/ethanol mixture. In addition the amount of extracted DEHP is proportional to the leaching temperature and added ratio of DEHP. The behavior of DEHP migration from flexible PVC sheets was described by the Ficks's law with <TEX>$2.72-10.1\;{times}\;10^{-10}$</TEX> cm²/s of the diffusion coefficients.

Migration of phthalates from PVC toys into saliva simulant by dynamic extraction

Soft PVC children's products are usually plasticized with phthalates. As young children suck and chew on toys, they extract and ingest certain quantities of the plasticizers. Some phthalates are suspected to affect the kidneys and liver and cause testicular damage. Therefore, the EC has prohibited the sale of toys and childcare articles intended to be placed in the mouth by children <3 years of age made of soft PVC containing >0.1% by weight of six phthalates (1999/815/EC). The aim was to study the materials and plasticizers used in soft children's products. In February 2001, a market surveillance was performed in The Netherlands and 62 soft toys were sampled. Forty-seven of these toys contained plasticized PVC. Diisononylphthalate (DINP) and di(2-ethylhexyl)phthalate (DEHP) were the predominant plasticizers and were usually found in concentrations between 30 and 45% by weight. One teething ring was made of PVC plasticized with 45% by weight of DINP and was not in compliance with Decision 1999/815/EC. The DINP and DEHP migration was determined in saliva simulant using the ‘Head over Heels’ agitation method. All toys complied with the Scientific Committee on Toxicity, Ecotoxicity and the Environment (SCTEE) guidance release value of 6.7 µg min-1 10 cm-2. The DEHP migration of six toys exceeded the SCTEE guidance release value of 1.7 µg min-1 10 cm-2. Substitutes found for phthalates plasticizers are acetyltributylcitrate, tributylcitrate and diisononyladipate. In addition, other plasticizers and additives were found in minor amounts. The toxicity and the migration behaviour of these substances is less known and requires more attention. To ensure the safety of PVC toys, these substances should also be regulated.

Migration of di(2-ethylhexyl) phthalate from polyvinyl chloride tubes used in preparation of foods

Three samples of polyvinyl chloride products for food use were examined for di(2-ethylhexyl) phthalate (DEHP) migration levels under the conditions described in the Japanese Food Sanitation Law. These samples were two kinds of tubes and one stretched film, containing 12 to 41% DEHP by weight. DEHP migration levels from them were very low, all below 0.1 ppm, into 3 kinds of food simulant; water, 4% acetic acid and 20% ethanol. However, high levels of DEHP migrated into n-heptane, 12 ppm from the stretched film sample and more than 800 ppm from the tube samples. Migration from the 2 tubes was higher than 150 ppm, the limit of residues after evaporation in containers and wraps. Though the limit of residues after evaporation is not set for equipment used in the preparation of foods, the tested tubes were considered to be unsuitable for uses in which they come into direct contact with oils, fats or oily foods.

Di(2-ethylhexyl) phthalate contamination of retail packed lunches caused by PVC gloves used in the preparation of foods

Plasticizer contamination of foods sold in retail packed lunches and set lunches in restaurants was determined by GC/MS. The phthalate esters were as follows: diethyl, dipropyl, dibutyl, dipentyl, dihexyl, butylbenzyl, dicyclohexyl, di(2-ethylhexyl), dioctyl, diisooctyl (mixture of isomers) and diisononyl (mixture). Di(2- ethylhexyl) adipate was also determined. Sixteen packed lunches and ten set lunches were analysed, and in all samples the concentration of di(2-ethylhexyl) phthalate (DEHP) was the highest, at 0.80–11.8 mg/ kg in packed lunches and 0.012–0.30 mg/kg in set lunches. The DEHP content of five packed lunches exceeded 1.85 mg, which is the EU tolerable daily intake (TDI) for a person of 50 kg body weight. Foodstuffs that were components of the packed lunches were taken from the factory at each step of preparation and phthalates were determined. For example, chicken contained 0.08 mg/kg DEHP when uncooked, 13.1 mg/ kg after frying and 16.9 mg/kg after packing. Disposable PVC gloves used in the preparation of foods were apparently the source of high DEHP concentrations. The gloves used during cooking or packaging were sprayed with 68% (w/w) ethanol to sterilize them. PVC gloves from the factory contained 22 or 41% by weight of DEHP. To confirm the link with the contamination problem, samples of boiled rice, croquette and boiled dry radish were handled in the laboratory with PVC gloves containing 30% (w/w) DEHP. DEHP migration levels of 0.05 mg/kg in rice or 0.33 mg/kg in croquette, and 11.1 mg/kg in radish were found. The alcohol sprayed onto the gloves increased the migration of DEHP to 2.03 mg/kg in rice, 2.45 mg/ kg in croquette, and 18.4 mg/kg in radish.

Plasticizer Migration from Blood Lines in Hemodialysis

Polyvinylchloride (PVC) is the most commonly used material for tubing in extracorporeal circulation. It is usually plasticized by the addition of di-2-ethylhexylphthalate (DEHP). The plasticizer is physically mixed into the PVC. The potential danger of DEHP migration into blood has been discussed. It has been suggested that the polyurethane (PUR) coating should reduce this transport. Eight different types of PVC tubing sets for hemodialysis were investigated for migration of DEHP. In general, they contained approximately 40% by weight of plasticizer. It was shown that approximately 60 mg plasticizer could be extracted from complete tubing sets during a 6-h period. The release rate of DEHP from the PUR coating compared with PVC was increased. The results show that in contrast to previously published information, PUR coating of PVC tubing is not an effective method for reducing migration.

Determination of di-2-ethylhexyl phthalate levels in human blood plasma and cryoprecipitates.

While investigating the possible occurrence of neutral plasmalogens in human blood, we isolated a substance which had the same chromatographic characteristics on thin-layer chromatoplates as those of alkyl diglycerides. This substance was identified (1) as di-2-ethylhexyl phthalate (DEHP), and we were able to demonstrate (2) that this plastifier originated from the plastic transfusion packs which had contained the blood and that its concentration increased with the time of storage up to a level of about 11.5 mg/100 ml of plasma after 21 days. These observations were confirmed by Jaeger and Rubin (3), who have also shown that DEPH accumulates in liver cells during the perfusion of rat liver. These authors also found that liver, spleen, lung, and abdominal fat in two patients who had received blood transfusions contained significant quantities of DEHP. In the present report, we describe a direct method of determination of DEHP by gasliquid chromatography. With this method, we have been able to demonstrate that the leaching out of DEHP from plastic transufsion packs was correlated with the plasma concentration of triglycerides. Also the DEHP levels in cryoprecipitates, which are