Phthalates

The text on this page is taken from an equivalent page of the IEHIAS-project.

Phthalates are dialkyl- or alklarylesters of 1,2-benzenedicarboxilic acid. Di-2-ethylhexyl phthalate (DEHP) is the most produced compound and thus receives the most research attention. Most phthalates are used as plasticizers, from which they can leach. The most common use of DEHP is in polyvinyl chloride (PVC)

Phthalates as biomarkers

Sample collection and storage

Matrix:

• Blood, urine and saliva can be considered as matrices.
• Other, less common biomarkers include breast milk and amniotic fluid

Kinetics:

• Phthalate uptake generally occurs through foods into which phthalates have migrated from packaging, inhalation and dermal absorption.
• Uptake is in part determined by the type of phthalate concerned
• Exposed to long chain phthalates is mainly through ingestion, shorter chain compounds are more likely absorbed or inhaled
• Exposure of DEHP through food is estimated at 10 µg/kg BW/day.
• Metabolism is specific to differences between compounds and uptake routes. Because of rapid metabolization of DEHP, it is not expected to bioaccumulate.
• Typical half-lives of phthalates are in the range of 6-12 hours.

Sampling conditions:

Routine sampling procedures for urine, breast milk or blood. Saliva is collected in glass tubes and kept at -40°C.

Sample measurement

Analytical aspects:

• Blood or urine samples can be analyzed using HPLC or multidimensional LC/LC and tandem MS.
• Detection limits are in the range of 0,01-0,5 µg/l in blood and breast milk, and 1-30 ng/l for urine

Performance characteristics:

No data on inter- and intralaboratory variability is available

Validation:

No internationally harmonized programs are available

Confounding factors:

Oxidative metabolism of phthalate esters is significantly greater in children than in adults

Data interpretation

Analytical aspects:

• Blood or urine samples can be analyzed using HPLC or multidimensional LC/LC and tandem MS.
• Detection limits are in the range of 0,01-0,5 µg/l in blood and breast milk, and 1-30 ng/l for urine

Performance characteristics:

No data on inter- and intralaboratory variability is available

Validation:

No internationally harmonized programs are available

Confounding factors:

Oxidative metabolism of phthalate esters is significantly greater in children than in adults