19085-1701857-UL_Prop_65_Test_Results_2019

Released by UL Environment
Date Prepared:
February 11, 2019
Report #:
1000339735-1162663EA
©2019 UL LLC
CA Prop 65 Exposure Assessment Page 6 | 15
herein to represent the single-point discrete emission factors for use in Equation 1 for the
Execumat Chair Mats over the product life.
Flow Rates of Outdoor Ventilation Air
Ventilation, as defined here, is the flow rate of clean outdoor air into an occupied indoor space
or a building. Ventilation is the primary means of reducing the concentrations of air
contaminants that are generated indoors. Each of the three exposure scenarios that are
evaluated herein has a characteristic ventilation airflow rate that is independently selected for
use in the model.
The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE)
publishes standards that provide professional guidance on minimum ventilation rates for most
building types and occupancies. These guidelines are based largely on human perceptions of
air quality and comfort. ASHRAE Standard 62.1, “Ventilation for Acceptable Indoor Air Quality”
(ASHRAE, 2016a), which covers offices, schools, and other building types except residential,
either forms the basis for most mechanical building codes or is directly referenced by the codes
themselves. For example, the 2013 California Mechanical Code in California Code of
Regulations, Title 24, Part 4 (CBSC 2013) directly references and reproduces ASHRAE
Standard 62.1 within Table 6-2 in Table 4-1, “Minimum Ventilation Rates in Breathing Zone.”
The ventilation requirements in ASHRAE Standard 62.2, “Ventilation and Acceptable Indoor Air
Quality in Low-rise Residential Buildings” (ASHRAE, 2016b) are replicated in the California
Building Code for residential construction. These codes are enforceable by law in all state
jurisdictions not covered by local building codes. Additionally, state codes are the foundation of
all local building codes in California.
Private office scenario
Carter and Zhang (2007) plotted the frequency distribution of the floor areas of 430 single
occupancy private office workstations in randomly selected floor plans. The 50
th
percentile
workstation floor area was 13.47 m
2
(145 ft
2
). With apportioned general office common space,
the total, 50
th
percentile open-plan workstation floor was 23.78 m
2
(256 ft
2
). The minimum
ventilation requirements for an office environment as defined in the 2007 version of ASHRAE
62.1, Table 6-1, are 2.5 L/s person (5 cfm/person) and 0.3 L/s-m
2
floor area (0.06 cfm/ft
2
). The
objective is to provide sufficient ventilation to dilute pollutants both associated with an occupant
and emanating from the space. Applying these requirements to the 23.78-m
2
single-occupant,
private office, the calculated minimum ventilation airflow rate is 34.7 m
3
/h (9.63 L/s or 20.4 cfm).
The standard private office scenario defined in CDPH Standard Method V1.2 (Table 4-4) is
commonly used for assessing VOC emissions from building products and office furniture. While
the origin for this private office scenario is not identified in the standard, it is claimed to be
representative of an enclosed office in a public/commercial building. The floor dimensions are
3.66 m (12 ft.) by 3.05 m (10 ft.) yielding a floor area of 11.15 m
2
. Application of the minimum
ventilation requirements from ASHRAE 62.1 results in a minimum total flow rate of outdoor air
during occupied hours of 20.7 m
3
/h (5.76 L/s or 12.2 cfm). Although the CDPH standard private