Blueprint for the design, construction, and validation of a plastic and phthalate-minimised laboratory
Cassandra Rauert, Xianyu Wang, Nathan P. Charlton, Chun-Yin Lin, Cheng Tang, Ian Zammit, Ayomi Jayarathne, Christos Symeonides, Emily White, Michael Christensen, Valentina Ponomariova, Jochen F. Mueller, Kevin V. Thomas, Sarah A. Dunlop
Abstract
Micro and nanosized plastics (MNPs), and a range of associated additive chemicals, have become pervasive contaminants that humans and the environment are exposed to everyday. However, one of the principal challenges in their analysis is adequate strategies to minimise background contamination. Here a blueprint for a specialised plastics and additive-minimised clean room laboratory built for this purpose is presented. Common laboratory construction materials (n=23) were tested, including acoustic baffles, ceiling materials, floor materials, glazing rubber, and silicone sealant. The % polymer content ranged from 2–76% w/w while the sum concentration of six phthalates ranged from 0.81 (0.73–0.86) to 21000 (15000–27000) mg/kg, assigning many of these materials as inappropriate for use in a clean room environment. The final design of the laboratory consisted of three interconnected rooms, operated under positive pressure with the inner rooms constructed almost entirely of stainless steel. Background concentrations of MNPs and phthalates in the new laboratory were compared to two Physical Containment Level 2 (PC2) laboratory environments, with concentrations of MNPs reduced by >100 times and phthalates reduced by up to 120 times. This study reports the first known clean room of its kind and provides a blueprint for reference and use by future plastics research. Both micro/nano plastics and plastic additives are considered hazardous materials due to documented environmental and human health effects including toxicity towards a range of biota (MNPs) and endocrine disrupting effects in humans (phthalates). However, one the largest challenges in assessing these hazards is producing reliable data including minimising blank contamination. This study presents the first plastic minimised clean room of its kind reporting a >100x reduction in background contamination, allowing more confidence in data reporting lower concentrations of these contaminants.