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 4 | 15
ROUTES OF EXPOSURE TO VOCS RELEASED FROM THE EXECUMAT CHAIR
MATS
1,4 dioxane, acetaldehyde, and cumene are classified as volatile organic chemicals (VOCs) and
are present in air mostly in the gas phase. Therefore, the release of these VOCs from
consumer products to indoor air results predominantly in exposure through inhalation of the gas-
phase.
A consumer’s daily inhalation exposure to 1,4 dioxane, acetaldehyde or cumene released from
the Execumat Chair Mats is based on (1) the emission rate of the substance from the material,
(2) the resulting estimated indoor air concentration, and (3) the daily breathing rate within the
affected environment. The 1,4 dioxane, acetaldehyde and cumene emission rates used herein
are based on product-specific air chamber analysis results. Indoor air concentrations, breathing
rates and occupancy patterns are specific to either the occupational or residential setting and
are based on conservative assumptions. The values selected for the exposure parameters are
discussed in detail below.
Estimating 1,4 dioxane, Acetaldehyde and Cumene Air Concentrations
Indoor air concentrations within this report are estimated using a simplified steady-state mass
balance model described in ASTM Standard Guide D5116, “Standard Guide for Small-Scale
Environmental Chamber Determinations of Organic Emissions from Indoor Materials/Products”
(ASTM, 2010). This model is commonly used to estimate indoor air concentrations associated
with product emissions of VOCs. For example, this model is incorporated into UL 2821
“GREENGUARD Certification Program Method for Measuring and Evaluating Chemical
Emissions From Building Materials, Finishes and Furnishings” and the California Department of
Public Health, “Standard Method for the Testing and Evaluation of Volatile Organic Chemical
Emissions from Indoor Sources Using Environmental Chambers Version 1.2,” (CDPH, 2017).
Steady state conditions with respect to emission rates and building ventilation are assumed in
making the estimation. Additional model assumptions include zero outdoor concentrations,
perfect mixing within the building and no net losses of VOCs gases from air due to other effects
such as irreversible or net sorption on surfaces (i.e., net sink effects) and chemical reactions.
Indoor air concentrations are estimated as follows:
C

= EF

×


(Equation 1)
Where:
C
a
= Estimated indoor air concentration (µg/m
3
)
EF
A
= Unit specific emission rate or emission factor (µg/ft
3
h
-1
)
A = Surface area of emitting source (ft
3
)
Q = Ventilation airflow rate (m
3
h
-1
)