PVC flooring at home and uptake of phthalates in pregnant women

Phthalates are used as plasticizers in polyvinyl chloride (PVC) materials and it is known that phthalates may migrate into the surrounding environment and then become a source for human uptake. The aim of the study was to investigate whether residential PVC flooring was related to the urinary levels of phthalate metabolites determined in pregnant women. The data were from the Swedish SELMA study where sampling was conducted during the time period 2007‐2010. Spot urine samples from 1674 women at the end of the first trimester were analyzed for 14 metabolites from seven phthalates and one phthalate alternative. Data on flooring material in the kitchen and the parents’ bedrooms as well as potential confounders were collected by postal questionnaires at the same time as the urine samples were taken. Multiple regression modeling by least square geometric mean and weighted quantile sum regression was applied to log‐transformed and creatinine‐adjusted phthalate metabolite concentrations adjusted for potential confounders from questionnaire data. This study has found significantly higher urinary levels of the BBzP metabolite (MBzP) in pregnant women living in homes with PVC flooring as compared to homes with other flooring materials.     

Synthesis and Functional Evaluation of Soy Fatty Acid Methyl Ester Ketals as Bioplasticizers

A facile synthesis of the soy fatty acid methyl ester ketal has been accomplished using acetone in the presence of catalytic anhydrous ferric chloride starting from commercially available soy biodiesel (soy fatty acid methyl ester) after evaluating various synthetic procedures. The soy ketal product was fully characterized by nuclear magnetic resonance, infra-red and chromatography. The physical and analytical properties of soy ketal as determined by thermogravimetric analysis, viscosity acid and saponification values are acceptable for plasticizer applications. Soy ketal was compounded with polyvinyl chloride for evaluation of plasticizer properties such as efficiency, gelation, viscosity, volatility, thickening/aging behavior and stability. The thickening and aging behaviors of the soy ketal bioplasticizer are better than those of petroleum-based plasticizers such as diisononyl phthalate and diisononyl-cyclohexane dicarboxylate, but they need improvement in the areas of thermal stability and water extractability.     

Beyond phthalates: Gas phase concentrations and modeled gas/particle distribution of modern plasticizers

The ongoing health debate about polymer plasticizers based on the esters of phthalic acid, especially di(2-ethylhexyl) phthalate (DEHP), has caused a trend towards using phthalates of lower volatility such as diisononyl phthalate (DINP) and towards other acid esters, such as adipates, terephthalates, citrates, etc. Probably the most important of these so-called “alternative” plasticizers is diisononyl cyclohexane-1,2-dicarboxylate (DINCH). In the indoor environment, the continuously growing market share of this compound since its launch in 2002 is inter alia apparent from the increasing concentration of DINCH in settled house dust. From the epidemiological point of view there is considerable interest in identifying how semi-volatile organic compounds (SVOCs) distribute in the indoor environment, especially in air, airborne particles and sedimented house dust. This, however, requires reliable experimental concentration data for the different media and good measurements or estimates of their physical and chemical properties. This paper reports on air concentrations for DINP, DINCH, diisobutyl phthalate (DIBP), diisobutyl adipate (DIBA), diisobutyl succinate (DIBS) and diisobutyl glutarate (DIBG) from emission studies in the Field and Laboratory Emission Cell (FLEC). For DINP and DINCH it took about 50 days to reach the steady-state value: for four months no decay in the concentration could be observed. Moreover, vapor pressures p₀ and octanol-air partitioning coefficients K_OA were obtained for 37 phthalate and non-phthalate plasticizers from two different algorithms: EPI Suite and SPARC. It is shown that calculated gas/particle partition coefficients K_p and fractions can widely differ due to the uncertainty in the predicted p₀ and K_OA values. For most of the investigated compounds reliable experimental vapor pressures are not available. Rough estimates can be obtained from the measured emission rate of the pure compound in a microchamber as is shown for di-n-butyl phthalate (DnBP), di(2-ethylhexyl) adipate(DEHA), tri(octyl) trimellitate (TOTM) and DEHP.