Biomonitoring, the direct measure of all sources of exposure, is the gold standard of monitoring and is acore element of chemicals management. Human biomonitoring data informs all phases of chemicalsmanagement, from risk assessment to risk management, program performance indicators, and publichealth decision making.Perfluoroalkyl substances (PFAS) are a class of approximately 5000 chemicals with heat, oil and repellantproperties. They are found in a wide range of consumer products including cookware, food packaging,and stain and water repellant fabrics. Data are limited on exposure levels and health effects in Canadians,especially vulnerable populations. These chemicals do not break down easily, and are widely found in theenvironment and in humans. Studies have shown that exposure to certain PFAS cause health effects,including effects on the immune and endocrine systems.Advance Contract Award NoticePage 2 of 4Identifying exposure levels to multiple PFAS of interest and their potential associations with endocrineeffects or immune function would address an important gap in scientific understanding and contribute topolicy guidelines for these chemicals.The work described in the requirement will provide necessary data to address this data gap by measuringnine PFAS of interest (Table 1) in plasma biospecimens from two different Canadian biobanks.Biomonitoring of this important chemical class in these stored samples is cost effective, timely andforward-looking strategy. Data will support Health Canada's risk assessment and risk managementactivities under the chemicals management plan, as well as Health Canada's obligation to undertakeresearch into endocrine disrupting substances under the Canadian Environmental Protection Act, 1999.Table 1: Selected PFAS of interestPFAS Acronym Detection Limit (µg/L)Perfluorooctanoic acid PFOA 0.066Perfluorooctane sulfonate PFOS 0.430Perfluorohexane sulfonate PFHxS 0.063Perfluorononanoic acid PFNA 0.130Perfluorodecanoic acid PFDA 0.092Perfluorobutanoic acid PFBA 0.075Perfluoroundecanoic acid PFUDA 0.120Perfluorobutane sulfonate PFBS 0.066Perfluorohexanoic acid PFHxA 0.084