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Because these residences will be constructed with CARB Phase 2 Formaldehyde ATCM <br />materials, and be ventilated with the minimum code required amount of outdoor air, the <br />indoor residential formaldehyde concentrations are likely similar to those concentrations <br />observed in residences built with CARB Phase 2 Formaldehyde ATCM materials, which <br />is a median of 24.1 µg/m3 (Singer et. al., 2020) <br />Assuming that the residential occupants inhale 20 m3 of air per day, the average 70-year <br />lifetime formaldehyde daily dose is 482 µg/day for continuous exposure in the <br />residences. This exposure represents a cancer risk of 120 per million, which is more than <br />12 times the CEQA cancer risk of 10 per million. For occupants that do not have <br />continuous exposure, the cancer risk will be proportionally less but still substantially over <br />the CEQA cancer risk of 10 per million (e.g. for 12/hour/day occupancy, more than 6 <br />times the CEQA cancer risk of 10 per million). <br />Appendix A, Indoor Formaldehyde Concentrations and the CARB Formaldehyde ATOM, <br />provides analyses that show utilization of CARB Phase 2 Formaldehyde ATCM materials <br />will not ensure acceptable cancer risks with respect to formaldehyde emissions from <br />composite wood products. <br />Even composite wood products manufactured with CARB certified ultra low emitting <br />formaldehyde (ULEF) resins do not insure that the indoor air will have concentrations of <br />formaldehyde the meet the OEHHA cancer risks that substantially exceed 10 per million. <br />The permissible emission rates for ULEF composite wood products are only 11-15% <br />lower than the CARB Phase 2 emission rates. Only use of composite wood products made <br />with no -added formaldehyde resins (NAF), such as resins made from soy, polyvinyl <br />acetate, or methylene diisocyanate can insure that the OEHHA cancer risk of 10 per <br />million is met. <br />The following describes a method that should be used, prior to construction in the <br />environmental review under CEQA, for determining whether the indoor concentrations <br />resulting from the formaldehyde emissions of specific building materials/furnishings <br />selected exceed cancer and non -cancer guidelines. Such a design analyses can be used to <br />5of19 <br />