Plasticizers, antioxidants, and other contaminants found in air delivered by PVC tubing used in respiratory therapy

Abstract

Of the many compounds that leach from respiratory therapy tubing into air passing through it, we selected five compounds to analyze. The five compounds are known to be potentially carcinogenic, toxic or known to induce estrogenic activity. Parts-per-million and parts-per-billion concentrations of these species were found in the air passing through the tubing: the plasticizers di-(2-ethylhexyl) phthalate (DEHP) and di-ethyl phthalate (DEP), the antioxidants butylated hydroxy toluene (BHT) and p-nonylphenol (p-NP), and the contaminant (from commercial preparation of DEHP) 2-ethylhexanol (2-EH). These levels are high enough to cause some concern about exposure for patients who use oxygen on a long-term basis, those sensitive or allergic to these species, or those with asthma. A method was developed for analysis of solid tubing samples, showing great variability in concentrations of small, volatile molecules from sample to sample. A method was also developed for pre-concentration of small molecules onto Tenax adsorbants from air passing through the tubing. Both solid samples and adsorbant loaded with analyte were analyzed by direct dynamic thermal desorption gas chromatography mass spectrometry (GCMS). This study does not imply that adverse reactions by patients to chemical compounds leaching from respiratory medical tubing will occur but that further investigation is warranted.

Contaminant release from aged microplastic

“…Butylhydroxytoluene is an antioxidant commonly found in PVC. [42] No compounds could be identified explaining the formation of new C=O bounds visible in the IR spectra. This could be because the parts of the polymer or the compounds that have undergone the change are not leached during the column percolation experiment.…”

Phthalates and other additives in plastics: human exposure and associated health outcomes

“…Di(2-ethylhexyl) phthalate was also found in the lung tissue of one of the patients who died of a pneumothorax soon after birth (Roth et al 1988). These findings have not been replicated, but several authors have suggested that PVC medical tubing may be a likely source of respiratory health effects in young neonates (Hill et al 2001(Hill et al , 2003Tickner et al 2001). One study of adults found an inverse relationship between urinary MEP and MBP and pulmonary function (Hoppin et al 2004), but because urine markers reflect all routes of exposure and may not be a good measure of inhaled phthalate concentrations, it is difficult to interpret these results.…”

Effect of surfactants on plasticizer biodegradation by Bacillus subtilis ATCC 6633

“…These lipophillic compounds are added to plastics in order to impart a variety of desired properties to the formulations (Wilson 1995). They are not covalently bound to the plastics in these mixtures and are susceptible to leaching (Bauer and Herrman 1997;Fujii et al 2003;Hill et al 2003). Since plastic formulations, such as those used with PVC, can contain up to 40% plasticizer by weight (Graham 1973), even a very gradual loss of plasticizer can become a very significant source of environmental contamination.…”