Lumber Liquidators Chinese Manufactured Laminate Flooring ATTORNEY-CLIENT PRIVILEGED Lumber Liquidators Chinese Manufactured Laminate Flooring Evaluations of Formaldehyde Emissions from Installed Laminate Flooring and Risk to Lumber Liquidators Customers DRAFT

Objective Collect representative and statistically robust data sets for analysis Conduct evaluations to characterize airborne formaldehyde concentrations in residences specifically from installed Lumber Liquidators (LL) Chinese manufactured laminate flooring to assess consumer risk Characterize acute irritation risk and chronic cancer risk from formaldehyde emissions from LL laminate flooring for its U.S. customers using standard and accepted methods DRAFT

LL Evaluation Approach Step 1: Characterize formaldehyde emissions from new flooring Step 4: Characterize emission decay rate and develop model to estimate initial and TWA formaldehyde concentrations in customer residences from laminate flooring Step 2A: Measure indoor formaldehyde concentrations in residences of LL customers Step 2B: Survey customers to collect data on home conditions related to emissions Step 3 Characterize emissions from installed flooring of customer residences with “elevated” badge concentrations Step 5 Calculate residence-specific initial and TWA formaldehyde concentrations from laminate flooring and assess consumer risk from flooring emissions DRAFT

Formaldehyde Emissions from New Laminate Flooring Manufactured 2009-2015: Phase I Testing Results Parameter LL CPSC Sample Size (# of tests) 399 33 Mean ER (µg/m2/h)* 61 65 ER = emission rate * No significant difference between LL and CPSC mean emission rate DRAFT

LL Customer Population Badge Results 31,760 badge results available from 19,316 residences >99.5% of badges have concentrations ≤0.250 ppm Approximately 91% had formaldehyde concentrations ≤100 µg/m3 or ≤81ppb (WHO Guideline); substantial majority were <50 µg/m3 or <40ppb Approximately 9% (~1,940 residences) had concentrations >100 µg/m3 These customer residences were selected to focus further evaluations of flooring-specific contributions to residential formaldehyde concentrations DRAFT

Survey of Phase II Participants ~1,660 completed surveys as of March (out of ~2,900 residences) subset including reported laminate-board measure: n = 899* Age of Residences* Representative air exchange rate (AER) derived from age of residence ≤20 years old (44%) (assumed AER = 0.329; Persily et al. 2010) >20 years old (56%) (assumed AER = 0.621; conditional on ≤20-yr data) Area of laminate flooring in each residence* Floor area of residence from survey and area of flooring purchased from customer records Combined to estimate residence-specific Flaminate (fraction of total floor area covered with laminate) Mean Flaminate = 0.458 5.8% Flaminate = 1 (100% coverage) DRAFT

Profile of LL U.S. Laminate Customer Population (for Comparison) California customers who installed LL Chinese laminate flooring between 2011 and 2015 based on Experian data, as surrogate for U.S. customers Age of residence Based on age of home 25% residences constructed after 1990 with possible “tight” construction) 75% residences constructed in decades before 1990 Fraction of floor area as LL laminate Mean Flaminate = 0.32 79% of customers have Flaminate ≤0.50 0.02% have Flaminate of 1.0 (100% coverage) DRAFT

Greater Phase I Emission Rates Indicate Decay of Formaldehyde Concentrations Over Time DRAFT

Decay Pattern Estimated from Combined Phase I and Phase II Test Results NOTES:   biexp(p, k1, k2) = p exp(–k1 t)  +  (1–p) exp(–k2 t) Blue parameter values are those of the Bogen (2015) fit to Zinn et al. (1990) data The biexp fit is significantly better than the Zinn-fit-conditioned fit DRAFT

Current Residential Formaldehyde Concentrations for Phase II Customers 899 emission rates from Phase II testing All residences have estimated current flooring-related formaldehyde concentrations <90 µg/m3; 99.9% are <35 µg/m3 Mean flooring-related current formaldehyde concentration = 5.2 µg/m3 DRAFT

Selected Percentile and Mean Concentrations in Residences Initial Formaldehyde Concentration from Laminate Flooring in Residences with Elevated Badge Concentrations Based on Residence-Specific Phase II Emissions Data (n = 899) Initial Formaldehyde Concentration (µg/m3), unadjusted for residential occupancy   Residence duration Selected Percentile and Mean Concentrations in Residences (years) Fdecay Foccup 5 10 25 50 Mean 75 90 95 1.0000 2.12 3.72 8.85 18.4 23.3 30.2 48.5 66.1 DRAFT

Selected Percentile and Mean Concentrations in Residences TWA Formaldehyde Concentrations (CTWA) from Laminate Flooring in Residences with Elevated Badge Concentrations Based on Residence-Specific Phase II Emissions Data (n = 899) TWA Formaldehyde Concentration (µg/m3), unadjusted for residential occupancy Residence duration Selected Percentile and Mean Concentrations in Residences (years) Fdecay Foccup 5 10 25 50 Mean 75 90 95 2 0.3363 1.0000 0.71 1.25 2.98 6.19 7.84 10.2 16.3 22.2 12 0.2262 0.48 0.84 2.00 4.16 5.27 6.83 11.0 14.9 20 0.1862 0.39 0.69 1.65 3.42 4.34 5.62 9.03 12.3 26 0.1633 0.35 0.61 1.44 3.00 3.80 4.93 7.92 10.8 2 years is the exposure duration used in the ATSDR assessment 12 years is the average duration of residency in the U.S. (U.S. EPA Exposure Factors Handbook) 20 years is the expected use life of laminate flooring 26 years is the 90th percentile duration of residency in the U.S. (U.S. EPA Exposure Factors Handbook) DRAFT

Predicted TWA Formaldehyde Dose from Laminate Flooring in all Residences with Phase II Emissions Data (n = 899) Residence Time (years) Median daily dose (µg/day) Mean daily dose 12 8.5 11 20 15 26 13 17 Note: Proposition 65 safe harbor dose is 40 µg/day DRAFT

Conclusions Installed LL Chinese manufactured laminate flooring poses neither a significant acute irritation risk nor chronic cancer risk to customers Substantial sampling, testing and risk assessments have been performed to characterize formaldehyde in residences with installed LL Chinese manufactured laminate flooring Only ~9% of the ~ 20,000 residences with LL laminate flooring samples had total formaldehyde concentrations from all sources >100 µg/m3, the WHO Guideline None of the residences with elevated badge concentrations currently has a formaldehyde concentration from flooring >100 µg/m3 Only 6 out of 899 of the residences with elevated badge concentrations are estimated to have had initial formaldehyde concentrations >100 µg/m3 (<1%) Rate of formaldehyde emissions and in-residence concentrations diminish by >3-fold within one year of installation and continue to diminish slowly thereafter Estimated median and mean daily formaldehyde doses from laminate flooring for customers in residences with elevated badge concentrations are below the Proposition 65 safe harbor level of 40 µg/day for formaldehyde as a carcinogen Based on the U.S. EPA cancer model, average and upper bound TWA exposures from laminate flooring for the 9% of customer with residences with elevated badge concentrations are expected to pose cancer risks of <1 to 3 in 100,000 The vast majority of LL laminate customers have cancer risks <1 in 1,000,000 from LL Chinese manufactured laminate flooring DRAFT