Quantifying the Disposal of 

Post-Consumer Architectural Paint 

April 2007 

Prepared for 

Sector Strategies Division 

Office of Policy, Economics and Innovation 

U.S. Environmental Protection Agency 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 

Prepared by 

Abt Associates Inc. 

55 Wheeler Street 

Cambridge, MA 02138 

2 
Contents 

1. Introduction .................................................................................................. 5

2. Data Collection............................................................................................... 7

California ....................................................................................................... 7

MSW – 1999 and 2003 California Statewide Waste Disposal Characterization 

Studies .......................................................................................... 7

HHW – FY1998/1999 and FY2002/2003 California HHW Collection .................. 9

Combined Paint Estimate: MSW and HHW...............................................10

Ongoing or Upcoming Studies..............................................................11

Iowa............................................................................................................ 11

MSW – 1998 Iowa Solid Waste Characterization Study ................................11

HHW - FY1998 Iowa Regional HHW Collection..........................................12

Combined Paint Estimate: MSW and HHW...............................................13

Ongoing or Upcoming Studies..............................................................14

Oregon ........................................................................................................ 14

MSW – 2000 and 2002 Oregon Solid Waste Characterization and Composition 

Studies .........................................................................................14

HHW – 2000 and 2002 Oregon HHW Collection .........................................17

Combined Paint Estimate: MSW and HHW...............................................18

Ongoing or Upcoming Studies..............................................................18

Washington................................................................................................... 19

MSW – 2003 Waste Composition Analysis for the State of Washington.............19

HHW – 2003 Washington Moderate Risk Waste Collection............................20

Combined Paint Estimate: MSW and HHW...............................................21

Ongoing or Upcoming Studies..............................................................21

Wisconsin..................................................................................................... 21

MSW - 2002 Wisconsin Statewide Waste Characterization Study ...................21

HHW – 2001 Wisconsin HHW Collection ..................................................22

3 
Combined Paint Estimate: MSW and HHW...............................................24

Summary of State MSW Studies ...........................................................................25

3. National Estimates of Paint Disposal ...................................................................... 26

Alternative Estimation Methods ..........................................................................28

National Estimate Compared with PPSI Estimate .....................................................30

4. Conclusions ..................................................................................................... 31

References.......................................................................................................... 32

Appendix A: Data Refinements and Other Considerations .............................................. 35

Data Refinements ...........................................................................................35

Definition of “paint”........................................................................35

Architectural vs. Non-Architectural Paint...............................................36

Paint Weight ..................................................................................37

Dried Paint Weight ..................................................................37

Residual (Liquid Paint Weight.................................................... 39

Container Weight ................................................................... 39

Other Considerations .......................................................................................40

Paint Spillage .................................................................................40

Seasonal Collection Efforts.................................................................41

Paint Disposition/Management ............................................................41

Paint Misclassification.......................................................................41

Sample Size, Confidence Intervals, and Bias ...........................................41

4 
1. Introduction

Leftover architectural paint is a concern to communities across the country because of its high 

volume in the waste stream, resulting waste management costs, and potential for reduction, 

recovery, reuse and recycling. Leftover paint can also contain volatile organic compounds, 

fungicides and, in the case of very old paint, significant quantities of hazardous metals such as 

mercury and lead. Of all household hazardous wastes (HHW), paint is the single most voluminous 

and expensive material that many local governments collect and manage. To address the 

challenges of reducing and managing leftover architectural paint, state and local agencies have 

joined together with paint manufacturers, retailers, recyclers, and others, under the auspices of 

the Paint Product Stewardship Initiative (PPSI). These stakeholders are now exploring a broad 

range of issues and approaches to leftover paint management with the goal of working toward a 

nationally coordinated leftover paint management system. This analysis supports the PPSI by 

providing an estimate of the quantity of architectural paint disposed annually by consumers in the 

U.S. 

After a consumer has used paint from a particular purchase, any leftover paint may go into one of 

several disposition pathways. These include: 

Local municipal solid waste (MSW) landfill or incinerator (in liquid or dried form) 

Donation/exchange for reuse by another party 

Collection, management and disposal as hazardous waste, for example through a household 

hazardous waste (HHW) collection program 

Poured down a drain/sewer 

Stockpiled for future use or disposal (e.g., in a basement or garage) 

Because comprehensive national data on the quantities of post-consumer architectural paint going 

to these pathways is not available, this study examines available data from selected states. 

Specifically, this report presents case studies from the states of California, Iowa, Oregon, 

Wisconsin and Washington, each of which has availab le data on the quantity of paint disposed in 

MSW landfills and incinerators, as well as the quantity brought to HHW collection centers. It is 

believed that these two major pathways account for the vast majority of post-consumer paint 

disposed each year. The case studies provide state-specific estimates of the annual quantity of 

paint that is disposed. These data are then scaled to provide national estimates. 

Data on the quantity of post-consumer paint reaching MSW landfills and incinerators were 

obtained from MSW composition studies that were conducted in the five states. Data on the 

quantity of post-consumer paint brought to HHW collection sites were gathered directly from HHW 

program managers, or from published reports, for the annual period that most closely 

5 
corresponded to the year in which the state MSW composition study was conducted. Multiple 

years of MSW and HHW data were used in developing state-specific estimates, where available, to 

provide greater stability to the estimates, for a total of seven paired MSW/HHW data sets from 

the five states. Because of the relatively small quantity (and limited occurrence) of paint in the 

municipal solid waste stream, and the limited amount of sampling that states have been able to 

conduct in any individual MSW composition study, the estimates for paint disposal in the municipal 

solid waste stream in any individual state study are subject to higher error than those items that 

are more commonly found in the waste stream. Together, however, the seven state studies 

collectively represent the sorting of more than 4,500 samples of municipal solid waste, with a 

total sample weight of one million pounds or more. Reliance on the composite results of these 

seven studies reduces the uncertainty associated with the national estimates. 

The national estimates derived in this analysis are intended to update and refine the estimates 

provided in the 2004 PPSI document entitled “Background Report for the National Dialogue on 

Paint Product Stewardship.” That report estimated that approximately 2.5 to 5 percent of the 

architectural paint sold in the U.S. each year becomes leftover consumer house paint (PPSI 

2004a). The expanded analysis presented here estimates that the amount of architectural paint 

that is disposed of each year is equivalent to approximately 6 to 16 percent of sales, with a best 

estimate of 10 percent. The report is comprised of the following sections: 

Section 2 presents available data on the quantity of post-consumer paint disposed at MSW 

landfills and incinerators, and brought to HHW collection centers in each of the 5 states. 

Data from the state studies is combined in Section 3 to provide national estimates of postconsumer paint disposal. Section 3 also compares the annual quantity of post-consumer paint 

disposed to annual U.S. paint sales. 

Section 4 presents conclusions and opportunities for future research. 

Adjustments to state data (for comparability across waste studies and collection programs) and 

refinements to the national estimate are detailed in Appendix A. 

6 
2. Data Collection 

To estimate the quantity of post-consumer paint disposed annually in each of the five states 

studied, available data from multiple paint waste streams were examined. This included paint 

disposed of in municipal solid waste (MSW) landfills and incinerators, as well as paint collected at 

household hazardous waste (HHW) collection sites. This section presents data from MSW waste 

composition studies and HHW collection programs from each of the five states. 

California 

The California Integrated Waste Management Board (CIWMB) has conducted detailed municipal 

solid waste characterization studies, and has also compiled statistics on household hazardous 

waste collection programs around the state. Data on both of these waste streams provide a basis 

for estimating the total amount of post-consumer paint disposed each year in the state of 

California. 

MSW – 1999 and 2003 California Statewide Waste Disposal Characterization Studies 

CIWMB conducted detailed statewide MSW characterization studies in 1999 and 2003. In most 

respects, the 2003 California Statewide Waste Disposal Characterization Study followed the 

standards and protocols established for the 1999 Statewide Waste Disposal Characterization 

Study. For example, both studies divide California into five sampling regions (referred to as 

strata) based on similarities in demographics, climate, geography, and economic characteristics. 

Also, the definition of “paint” remained the same in both studies. Given that the two studies 

were conducted over a relatively short time interval, and the methods used for characterizing 

paint disposed across the state in both studies were relatively consistent, this report considers 

paint disposal quantities from both statewide studies. 

In both the 1999 and 2003 waste characterization studies, several disposal facilities (landfills and 

transfer stations) were randomly selected (i.e., with equal probability) in each of the five 

sampling regions as sampling sites for the single-family residential, commercial, and self-hauled 

waste streams. The number of single-family residential samples collected across all five regions 

was 148 in the 1999 study and 110 in the 2003 study, while the number of self-hauled samples 

collected was 247 in the 1999 study and 200 in the 2003 study. In addition, 80 multifamily 

residential samples were collected from randomly selected apartment buildings and complexes 

within the geographical areas surrounding the selected disposal sites in 1999 and 40 were 

collected in 2003. Finally, a total of 1,207 commercial generator samples were collected at 

randomly selected businesses in 1999, while in 2003, 200 samples were obtained from vehicles at 

7 
disposal facilities as a surrogate for commercial waste. It should be noted that not all MSW in 

California goes to a MSW landfill. California has three waste-to-energy incinerators that accept 

MSW. Further, one or two counties export MSW out of state. 

To account for seasonal variations in waste disposal patterns, waste sampling was conducted in 

different seasons. The 1999 study considered two seasons—winter and summer, while the 2003 

study was more detailed and also included autumn and spring. Each waste sample was hand 

sorted and characterized according to material types found in the California Integrated Waste 

Management Board’s Uniform Waste Disposal Characterization Method. The 2003 study increased 

the number of waste material types it considered; yet all material types were chosen and defined 

such that they could be fit to the material types used during the 1999 study. 

Both of the California waste studies defined paint as containers with paint in them. Paint types 

included in the definition are latex, oil-based, and tubes of pigment or fine art paint. The 

definition does not include dried paint, empty paint cans, or empty aerosol containers, which can 

often be found commingled with other waste types under “remainder/composite construction & 

demolition” or “tin/steel cans.” 

Table 1 presents the amount of paint disposed of in landfills or incinerated in California as 

presented in California’s 1999 and 2003 studies. The number of paint samples taken during each 

study was small; the disposal facilities considered for sampling in each study were selected with 

equal probability within each region (irrespective of the fact that these facilities could vary in 

size); and the studies did not employ sampling weights when estimating waste tons. Therefore, 

data from both studies were combined to generate a best estimate of paint disposed or 

incinerated in California. Combining these data could add stability to the estimate of paint in the 

MSW stream in California. 

Table 1. California Statewide Waste Characterization Study 

Results: 1999 and 2003 

Quantity (tons) Waste Category 1999 2003 Average 

MSW 37,500,002 40,235,328 38,867,665 

HHW 112,385 73,600 92,993 

Paint 44,498 19,192 31,845 

Paint as a % of MSW 0.12 0.05 0.08 

Paint as a % of HHW 40 26 34 

Sources: CIWMB, 1999 and 2003.

The study provides a 90 percent confidence interval for these estimates, 

even though sampling weights were not used to estimate the totals. 

As detailed in Table 1, the amount of paint disposed of in landfills or incinerated in 2003 was 

nearly 60 percent lower than in 1999. Due to the small number of paint-containing samples 

considered, a single sample could result in a large variation in disposal quantities. For example, 

8 
the inclusion of a single household that stockpiled large quantities of paint during one year could 

drive up paint disposal quantities. Averaging data from two study years help reduce the impact of 

such instances on the overall paint estimate. 

HHW – FY1998/1999 and FY2002/2003 California HHW Collection 

Local governments in California are required to keep HHW out of the solid waste stream pursuant 

to Public Resources Code 47100. They do this by providing both temporary and permanent HHW 

collection events and facilities, and public education to their residents. Currently, descriptive 

program information is available for the 1999 study, but not for that conducted in 2003. In fiscal 

year (FY) 1998/99, 85 permanent HHW collection facilities, 245 temporary facilities/one day 

events and 107 Recycle-Only facilities1

 were operated. About 50 percent of the state’s population 

had access to permanent facilities, and temporary facilities served about 40 percent of the 

population. Approximately 10 percent of the state’s population had no access to collection 

opportunities. While the majority of the public had access to HHW collection programs, actual 

usage may have been lower. Some HHW collection sites may not have been convenient due to 

location or operating hours. Advertising and outreach is limited by budget constraints (CIWMB, 

2001). Based on annual statistics, CIWMB estimates that only approximately 4 percent of residents 

participate in HHW collection programs each year (CIWMB, 2000). 

Local governments are required to report annually the quantity of waste collected by HHW 

programs and the method of waste management. The quantity of paint collected and the 

percentage of HHW that was paint during FY1998/99 and FY2002/03 are shown in Table 2. These 

quantities reflect only those amounts of paint actually collected in HHW programs. 

The quantity of HHW collected by California programs has grown, as has the percentage of the 

HHW that is paint, since the programs were first introduced in California in FY1993. In FY1993, 

approximately 3,000 tons of paint was collected, and paint accounted for 31 percent of all the 

waste collected at HHW collection centers. By FY2004, paint collection grew to 11,500 tons, or 

approximately 35 percent of all HHW collected. Data for 1998/99 and 2002/03 are used in this 

analysis due to availability of corresponding MSW information for those years. 

1

 Recycle-only facilities are those that receive materials that could potentially be recycled, including 

latex paint. 

9 
Table 2. Paint Collected in CA HHW Programs: FY1998/99 and FY2002/03 

Paint (tons) Waste Category 

FY1998/99 FY2002/03 Average 

Oil-Based Paint 3,650 5,161 4,406 

Latex Paint 3,722 5,324 4,523 

Total Paint Collected 7,372 10,485 8,929 

Total HHW Collected 17,247 24,750 20,998 

Percent of HHW Collected 

that is Paint (%) 43 42 43 

Sources: Data received from Anna Ward, CIWMB2004 and Glenn Gallagher, CIWMB, 2006. 

Combined Paint Estimate: MSW and HHW 

While it is legal to dispose of dried paint in MSW landfills in California, air drying is not 

encouraged. Instead, disposal of wet paint at HHW collections is the suggested management 

method. As shown in Table 3, approximately 78 percent of all of the paint that was disposed of in 

1999 and 2003 was disposed in MSW landfills or incinerated. The large percentage of paint in the 

MSW stream illustrates the importance of including MSW data when estimating the quantity of 

leftover paint in the United States. 

Table 3. Total Leftover Paint in California: Reported Data 

Disposition Pathway (tons)* 

Total Paint 

by Pathway (%) 

Percent of Paint 

MSW Landfill/Incineration 31,845 78 

HHW Collection 8,940 22 

Total 40,785 100 

Sources: CIWMB, 1999 and 2003, and data provided by Anna Ward, CIWMB, 

2004 and Glenn Gallagher, CIWMB, 2006. 

* Derived by averaging estimates from the 1999 and 2003 statewide waste 

characterization studies. 

In order to use these data to develop a national estimate, California’s data were adjusted (for 

example, to exclude quantities of non-architectural paints), as detailed in Appendix A 

(Refinements and Considerations). Table 4 presents California’s MSW and HHW data after these 

data refinements. 

10 
Table 4. Total Leftover Paint in California: Adjusted Values 

Disposition Pathway Total Paint 

(tons) Refinements 

MSW 

Landfill/Incineration 24,789 

* excludes non-architectural paint 

* excludes container weight 

* adds back dried paint 

HHW Collection 8,929 * none made 

Total 33,718 

Ongoing or Upcoming Studies 

California’s 2006 four-part Targeted Statewide Waste Characterization Study was scheduled to be 

released in the summer of 2006. California collects HHW data annually; the most current year of 

data available is for FY2004/05. This HHW data was not used because corresponding MSW data 

was not available. 

Iowa 

MSW – 1998 Iowa Solid Waste Characterization Study 

The 1998 statewide solid waste characterization analysis for Iowa was conducted in the fall of 

1997 and the spring of 1998. More than 420 samples of MSW were randomly selected from the 

residential, industrial/commercial/institutional (ICI), and mixed generator loads using various 

random cell selection processes. Once selected, the materials were sorted into 45 discrete 

material categories, weighed, and weights were recorded on individual data sheets based on the 

material classification determined during sorting. Data from these sites (together with data from 

a previous MSW characterization study conducted within the state) were used to develop waste 

composition estimates for the 45 material categories, as well as for the residential and ICI waste 

streams and for statewide totals. 

Paint is not defined specifically or quantified individually in this study. Rather, it is included in 

the “paints and solvents” subcategory, which is part of the broader household hazardous materials 

(HHM) category. Based on the experience and judgment of two professionals who conduct waste 

composition studies, paint is estimated to comprise approximately 90 percent of the “paints and 

solvents” subcategory2. Although Table 5 (below) presents the quantity including solvents, this 

quantity is ultimately excluded from our analysis, as detailed in Table 8. In addition, Table 5 

includes the weight of the container when the contents are liquid, while containers with dried 

2

 Based on conversations and data provided by Tanya Tarnecki of Cascadia Consulting, and Brad 

Anderson of Sky Valley Associates. 

11 
paint in them were placed in the “metal” category (Chamberlain, 2006). Table 8 also excludes 

container weight. 

Table 5. Iowa Statewide Landfill Composition Study Results: 1998 

Waste Type 

Household Hazardous 

Materials 

Quantity (tons) Percent of Total 

Waste (%) 

Percent of HHM 

(%) 

16,472 0.7 100.0 

Paint and solvents 2,797 0.1 17.0 

Total MSW 2,203,848 100.0 – 

Source: IA DNR, 1998.

Note: The study notes a 90 percent confidence interval for these estimates. 

HHW - FY1998 Iowa Regional HHW Collection 

In FY1998, Regional Collection Centers (RCCs) in Iowa collected over 620 tons of HHW. These 

facilities accept hazardous materials free of charge from households; they also accept paint and 

hazardous materials from Conditionally Exempt Small Quantity Generators (CESQGs)3 for a fee. 

Consisting of five permanent facilities, the RCCs serviced a population of 789,980 in 1998, and 

12,062 households (29,673 people)4 and 165 CESQGs brought paint to them. This represented 

approximately 3.8 percent of all households in the RCC service area (Theresa Stiner, Iowa DNR, 

2004). 

Latex paint and oil-based paint are two of the most common types of HHW and CESQG waste 

collected by RCC programs in the state. In 1998, a total of 198 tons of paint were collected by 

the RCCs, accounting for approximately 32 percent of all the waste collected. Approximately 36 

percent of this paint was oil-based and 64 percent was latex. 

In areas that did not have access to permanent RCCs, Iowa held 26 Toxic Cleanup Days (TCDs) in 

FY1998. TCDs are one-day events that accept hazardous materials free of charge from households 

and farms but charge a fee to CESQGs. In FY1998, 3,243 households participated out of 136,047 

households in the counties that held the events, representing approximately 2.4 percent of the 

households in the area. These events collected 47 tons of paint, which accounted for 

approximately 40 percent of all the waste collected (Theresa Stiner, Iowa DNR, 2004). 

The quantity of paint collected by RCC and TCD programs in Iowa and the percentage of HHW that 

is paint are shown in Table 6. In Iowa, some paint is weighed in cans and other paint is ‘bulked’ 

into 55-gallon drums before being weighed. The sum of the RCC and TCD quantities represents 

the total amount of HHW that was collected in Iowa for FY1998. 

3

 As defined by the Resource Conservation and Recovery Act (RCRA). 

4

 Based on an estimate of 2.46 persons per household in Iowa in 2000 (State Library of Iowa, 2004) 

12 
Table 6. Paint Collected at Iowa RCCs and TCDs: FY1998 

Waste Category (tons) 

RCC Total 

(tons) 

TCD Total 

(tons) 

HHW Total 

Bulk oil-based paint 51 NA 51 

Oil-based paint in cans 20 NA 20 

Bulk latex paint 113 NA 113 

Latex paint in cans 14 NA 14 

Total bulk paint 164 24 188 

Total paint in cans 34 23 57 

Total Paint Collected 198 47 245 

Total HHW collected 625 118 743 

Percent of HHW Collected 

that is Paint (%) 32 40 33 

Source: data provided by Theresa Stiner, IA DNR, 2004.

NA: Breakdown of oil-based and latex paint data are not available for TCDs.

Combined Paint Estimate: MSW and HHW 

Despite a restriction on landfill disposal of oil-based paint and wet latex paint, a large quantity of 

paint is disposed of in this manner every year. As shown in Table 7, approximately 92 percent of 

the paint that was disposed of in Iowa went to MSW landfills. 

Table 7. Total Leftover Paint in Iowa: Reported Data 

Disposition Pathway Total Paint (tons) Disposed by Pathway (%) 

Percent of Paint 

MSW Landfill 2,797 92 

HHW Collected* 245 8 

Total 3,042 100 

Sources: IA DNR, 1998; Theresa Stiner, IA DNR, 2004. 

* The HHW quantities reflect the total amount of paint collected at RCCs and 

TCDs. 

In order to use these data to develop a national estimate, Iowa’s data were adjusted (for 

example, to subtract the weight of paint containers), as detailed in Appendix A. Table 8 presents 

Iowa’s MSW and HHW data after these data refinements. 

Table 8. Total Leftover Paint in Iowa: Adjusted Values 

Disposition Pathway (tons) 

Total Paint Refinements 

MSW Landfill 1,615 

* excludes solvents 

* excludes non-architectural paint 

* excludes container weight 

HHW Collected 234 * excludes container weight (from 

portions that include it) 

Total 1,849 NA 

13 
As is the case in California, the large percentage of paint going to Iowa MSW landfills emphasizes 

the importance of including MSW data when estimating the quantity of leftover paint in the United 

States. 

Ongoing or Upcoming Studies 

Although Iowa’s 2005 Statewide Waste Characterization Study has been released, it was not 

available during the preparation of this report, and was therefore not included. The most current 

year of HHW data available for Iowa is 2005. 

Oregon 

MSW – 2000 and 2002 Oregon Solid Waste Characterization and Composition 

Studies 

The state of Oregon regularly conducts solid waste composition studies as required by state law. 

Statewide studies were conducted by the Department of Environmental Quality (DEQ) in 1992/93, 

1994/95, 1998, 2000, and 2002. This analysis considered the two most recent studies, from 2000 

and 2002, for the quantity and composition of paint collected and disposed to landfills or 

incinerated in Oregon. 

To conserve funds, the DEQ conducts “half-studies”, using a consistent general methodology. 

During each of the half study years used for this analysis, 2000 and 2002, the DEQ collected 300 

disposal site samples statewide, of which 75 were from the Metro tri-county area. Metro funded 

an additional 225 Metro-area samples. In addition, samples were collected by the DEQ, Metro, 

Marion County and the City of Eugene. These extra samples helped increase the precision of the 

statewide composition estimates. These studies also included contamination analyses (detailed 

sample analyses), discussed in Appendix A. 

The 2000 study comprised 591 composition samples in 2 geographic areas – Metro and the “rest of 

Oregon”. The 2002 study collected 844 composition samples in 4 geographic areas – Portland 

Metro, Marion County, Eugene and the “rest of Oregon.” The Metro area alone considered 350 

composition samples in 2000 and 349 in 2002. Within each geographic area, representative loads 

of waste weighing approximately 200 pounds from each load were selected as field samples. The 

2000 study considered waste samples from seven “waste substreams:” 

Residential route garbage trucks (over 90 percent of this waste is from single-family or 

multifamily residences)

Commercial route garbage trucks (over 90 percent of this waste is from businesses) 

Mixed route garbage trucks (contains a mixture of residential and commercial wastes) 

Compacting drop boxes (used by individual grocery stores, malls, or other retail operations) 

14 
Loose drop boxes (used for construction and demolition and for "yard-cleaning" activities) 

Self-haul (wastes hauled directly to the transfer station or landfill by the person or business 

that generated the waste) 

Mixed Solid Waste Processing Facility (MSWPF) residual wastes (wastes leftover for disposal 

after recoverable materials have been removed at the facility) 

In addition to these substreams, the 2002 study considered the following waste substream: 

Special Purpose Landfills (mostly collected either at general-purpose landfills or at transfer 

stations that ship all their waste to general-purpose landfills. In the Metro area however, 

significant waste amounts were from limited-purpose landfills that prohibit accepting food and 

other putrescible wastes.) 

The number of samples collected from each waste substream depended on the absolute quantity 

of waste disposed from each substream, and the expected variability of waste in the substream 

based on past composition studies. 

As part of the 2002 study, DEQ also conducted a “contamination analysis” to better characterize 

the actual quantities of solid waste materials being disposed. This effort was conducted with a 

goal of developing a “correction factor” for each material, which could then be multiplied by the 

field data results in order to determine more precisely the amount of each material, excluding 

contaminants, that was being disposed. The data presented in this section reflect the field data; 

details on the contamination analysis are presented in Appendix A. 

According to the 2000 and 2002 DEQ studies, more than 2.7 million tons of MSW were disposed in 

Oregon in landfills or solid waste burning facilities in each study year. Total MSW generated 

accounted for 75 percent of statewide solid wastes in 2000 and 73 percent in 2002.5 Table 9 

presents the amount of MSW paint disposed in Oregon in 2000 and 2002. 

5

 The remaining portion of solid wastes generated included industrial and other wastes, alternative daily cover, 

contaminated soils, inerts, asbestos, and septage sludge. Data in this report reflects MSW data and 

construction and demolition waste excluding pure inerts (for example, concrete). 

15 
Table 9. Paint Disposed in Oregon: 2000 and 2002 

Quantity (tons) Waste Type 2000 2002 Average 

Percent of Other 

Hazardous 

Materials (%)

 Percent of 

MSW (%) 

Latex Paint 704 2,489 1,597 9.9 0.1

 Oil Paints / Thinners 1,709 1,655 1,682 10.4 0.1

 Total Paint 2,413 4,144 3,279 20.2 0.1

 Total Other Hazardous 

Materials 14,047 18,346 16,197 100.0 0.6

 Total MSW 2,763,282 2,743,561 2,753,422 100.0 

Sources: OR DEQ, 2000 and 2002(a).

Percents are based on averaged "best estimates".

Paint is included in the “Other Hazardous Materials” category. 

Quantity of paint landfilled is derived based on the percent of paint in total solid waste.

Paint disposed includes latex paint and oil-based paints and thinners. Based on the experience and 

judgment of the professionals who conducted this waste composition study, oil paint is estimated 

to comprise approximately 95 percent of the “oil paints/thinners” subcategory.6 Table 10 

presents the breakdown of latex and oil-based paint by waste substream. 

Table 10. Paint Disposed in Oregon by Waste Substream: 2000 and 2002 

Latex (tons) Oil-Based/ Thinners 

(tons) Total Paint (tons) Waste Substream 

2000 2002 2000 2002 2000 2002 Average 

Residential Garbage Route Trucks 154 523 373 348 527 871 699 

Commercial Garbage Route Trucks 104 357 252 237 356 595 475 

Mixed Garbage Route Trucks 107 393 261 261 368 654 511 

Compacting Drop Boxes 47 176 115 117 162 293 227 

Loose Drop Boxes 80 247 195 164 275 411 343 

Self-Haul - Regular Landfill or T.S. 132 509 321 339 453 848 651 

Special Purpose Landfill (hauler & selfhaul) 43 138 105 92 149 230 189 

Residuals: Mixed Solid Waste Processing 

Facility 36 145 87 96 124 241 182 

Total 704 2,489 1,709 1,655 2,413 4,144 3,278 

Sources: O R DEQ, 2000 and 2002(a).

Quantity of paint landfilled is derived based on the percent of paint in total solid waste.

6

 Based on conversation with Brad Anderson, Sky Valley Associates. 

16 
HHW – 2000 and 2002 Oregon HHW Collection 

Oregon DEQ’s Solid Waste Policy and Program Development Section annually compiles a Material 

Recovery and Waste Generation Survey. Oregon’s waste haulers and private recycling companies 

are required to report the amount collected, county of origin, and markets for all of the 

recyclable materials they handle. Data on disposed tonnage comes from quarterly or annual 

disposal fee report forms. Together, recovery and disposal data are used to calculate total waste 

generation. 

In 2000, Oregon recovered 1,223 tons of latex and oil-based HHW paint and in 2002 they recovered 

1,586 tons, as shown in Table 11. HHW was recovered from Portland Metro and Oregon DEQ 

collection programs, garbage haulers across the state, the Knott Landfill (in Deschutes County) 

and a waste-to-energy plant in Marion County (for 2002 onwards). Not all programs provided data 

by paint type; of the available data, however, an average of 55 percent of paint was latex paint 

and 45 percent was oil-based (Peter Spendelow, 2004(b) and 2006(a)). Additional detail of the 

paint recovered by collection program is also available and has been presented in Table 11. 

During both years, Portland Metro’s HHW collection accounted for an average of 77 percent of the 

total HHW paint recovered across the state. (Peter Spendelow, 2004(b) and 2006(a)). 

Table 11. Paint Collected in OR HHW Programs: 2000 and 2002 

Latex Paint (tons) Oil-Based Paint (tons) Total Paint (tons) HHW Waste Collection 

2000 2002 2000 2002 2000 2002 Average 

Portland Metro HHW collection 571.6 660.8 419.1 497.0 990.7 1,157.8 1,074.2 

Garbage haulers (Marion County)* NA 188.7 NA NA 96.0 188.7 142.3 

Knott Landfill (Deschutes County) NA NA NA NA 19.8 70.2 45.0 

DEQ sponsored HHW collection 6.2 15.2 39.4 33.4 45.5 48.5 47.0 

Other garbage haulers** NA NA NA NA 14.6 8.0 11.3 

Lane County 0 0 56.0 0 56.0 0 28.0 

Marion County burned (oil-based)*** 0 0 0 112.6**** 0 112.6 56.3 

Total HHW Paint NA NA NA NA 1,222.6 1,585.8 1,404.2 

Source: Data provided by Peter Spendelow, OR DEQ, 2004(b) and 2006(a).

NA: Breakdown of latex versus oil-based paint is either not collected or not available.

* Of the 188.7 tons reported, 119 tons were reported by garbage haulers in Marion County and an additional 69 tons were 

reported by the county. 

** Marion county programs collect latex paint only, although it is possible that some oil-based paint is mixed in. (All Marion 

County’s oil-based paint gets burned in their waste-to-energy plant.) 

*** Paint from this source can probably be attributed to HHW collection events sponsored by the garbage haulers or collection 

at their disposal sites. 

**** Tons are an estimate of the amount of oil-based paint burned in the Marion County waste-to-energy plant. Based on a 

law passed in 2001, Marion County counts certain materials that are burned in their energy recovery facility towards the 

county recovery rate. These data are not estimated for 2001 and prior years. 

17 
Combined Paint Estimate: MSW and HHW 

As in other states, a large quantity of paint is disposed to landfills every year. As shown in Table 

12, the majority of disposed paint in Oregon was disposed at landfills. 

Table 12. Total Leftover Paint in Oregon: Reported Data

 Disposition Pathway Total Paint (tons) Disposition Pathway (%) 

Percent of Paint by 

MSW Landfill 3,279 70 

HHW Collection 1,404 30 

Total 4,683 100 

Sources: OR DEQ, 2000, 2002(a) and 2002(b), and data provided by Peter Spendelow, 

OR DEQ, 2004(b) and 2006(a).

Quantity of paint landfilled is derived based on the percent of paint in total solid 

waste. 

Total paint quantities are based on averaged "best estimates".

In order to use these data to develop a national estimate, Oregon’s data were adjusted (for 

example, to exclude thinners from the oil estimates), as detailed in Appendix A. Table 13 

presents Oregon’s MSW and HHW data after these refinements. 

Table 13. Total Leftover Paint in Oregon: Adjusted Values 

Disposition Pathway Total Paint 

(tons) Refinements 

MSW Landfill 2,507 

*excludes thinners 

*excludes non-architectural paints 

*excludes container weight 

*adds back dried paint 

HHW Collection 1,404 *none made 

Total 3,911 NA 

Ongoing or Upcoming Studies 

Oregon’s next statewide waste composition study was scheduled to be conducted in 2005 - the 

same year that statewide and wasteshed recovery goals were to be achieved under Oregon 

Revised Statute 459A.010. Consistent with past years, the study was to be conducted by the DEQ, 

with additional sponsorship by Metro. 

18 
Washington 

MSW – 2003 Waste Composition Analysis for the State of Washington 

The composition of solid waste in the State of Washington has been studied several times over the 

past 15 years. These studies have been conducted on a statewide basis (in 1987 and 1992) or on a 

more local basis (by various counties and cities). The data from statewide studies prior to 2003 

have become outdated by recent advancements in waste diversion programs (recycling and 

composting in particular) and by ongoing changes in consumer habits, shifts in packaging, and 

other factors. Therefore, only results for the 2003 study are discussed here. 

The 2003 Waste Composition Analysis for the State of Washington uses data from studies of 10 

counties and one city to estimate the quantity and percentage breakdown of 76 material 

categories making up the solid waste stream of Washington State. In order to extrapolate beyond 

these 11 jurisdictions to the whole state, the percentage breakdown of the material categories in 

each of these jurisdictions were applied to the disposal tonnages for other counties with similar 

demographics. Those figures were then summed to derive a statewide total for each waste 

category, as well as for residential and commercial sources and the waste stream as a whole. 

The statewide analysis focuses on MSW brought to landfills for disposal. Hazardous wastes are not 

addressed in the analysis, except in cases when these are disposed of with MSW. 

Latex paint and oil-based paint are included in the analysis as subcategories within the broader 

category of hazardous and special waste. Paint quantities include the weight of the container if 

over 50 percent of the combined weight appeared to be from paint (liquid or dried) (Hlavka, 

2006). Table 14 shows the total quantities of MSW, Hazardous and Special Waste, and paint waste 

going to MSW landfills in Washington. 

Table 14. Washington Statewide Waste Composition Study Results: 2003 

Waste Type (tons) 

Quantity 

Total Waste (%) 

Percent of 

HSW (%) 

Percent of 

Hazardous and Special 

Waste 50,090 0.90 100.0 

Latex Paint 8,250 0.15 16.5 

Oil Paint 2,810 0.05 5.6 

Total Paint 11,060 0.20 22.1 

Total MSW 5,538,700 100.0 – 

Source: WA ECY, 2003(b). 

There is a significant degree of statistical uncertainty associated with the tonnage figures 

presented in Table 14. These are uncertainties associated with the estimates that were generated 

for each of the 11 jurisdictions that served as the basis for the statewide waste composition 

19 
analysis. An additional and even larger source of uncertainty results from extrapolating the data 

from these jurisdictions to other counties, with all of the associated assumptions about similar 

demographics and other factors. The resulting level of uncertainty cannot be precisely quantified 

(WA ECY, 2003(b). 

HHW – 2003 Washington Moderate Risk Waste Collection 

In 2003, the state of Washington published the Solid Waste in Washington Twelfth Annual Status 

Report, which includes information on moderate risk waste (MRW). MRW is a combination of 

HHW, CESQG waste, and used oil (UO). HHW is considered waste that was generated in the home, 

while CESQG is small quantities of business or non-household waste. Both HHW and CESQG waste 

are exempt from most hazardous waste regulations. 

In Washington there are 42 programs that manage MRW. All 39 counties have some sort of MRW 

program (or access to a MRW program in a neighboring county). Three types of MRW collections 

operate in the state – permanent facilities, mobile units, and periodic collection events. It is 

estimated that 6 percent of all households in Washington use collection events and fixed facilities 

(WA, 2003a). 

In 2002, MRW programs in Washington collected over 6,750 tons of HHW, almost 4,600 tons of UO, 

and over 700 tons of CESQG waste, for a total of nearly 12,150 tons. 

Latex paint and oil-based paint are two of the dominant types of HHW and CESQG waste collected 

in the state. Approximately 44 percent of the paint that is collected as HHW, and approximately 

69 percent of the paint that is collected as CESQG waste, is oil-based. The amount of paint 

collected from households and from CESQGs, and the percentage of MRW that is paint are shown 

in Table 15. 

Table 15. Paint Collected in Washington MRW Programs: 2002 

Waste Category (tons) 

HHW 

(tons) 

CESQG 

(tons) 

Total 

Latex Paint 1,342 57 1,399 

Latex Paint, Contaminated* 428 1 430 

Oil-Based Paint 1,297 129 1,425 

Total Paint 3,067 187 3,254 

Total MRW 6,757 698 7,455 

Percen t of MRW that is Paint (%) 45.4 26.7 43.6 

Source: WA ECY, 2003(a). 

* Latex paint was classified as contaminated when paint containers included 

anything that made the latex paint un-recyclable; such as: latex paint mixed 

with solvents, oil-based paints, dirt or garbage, or other unknowns. 

20 
Combined Paint Estimate: MSW and HHW 

Despite restrictions on the landfill disposal of paint, a large quantity of paint is disposed of in this 

manner every year. As shown in Table 16, approximately 77 percent of the paint that was 

disposed of in Washington in 2002 went to MSW landfills. 

Table 16. Total Leftover Paint in Washington: Reported Data 

Disposition Pathway Total Paint (tons) Disposition Pathway (%) 

Percent of Paint by 

HSW in MSW Landfill 11,060 77 

MRW Collection 3,254 23 

Total 14,314 100 

Sources: WA ECY, 2003(a), and WA ECY, 2003(b). 

In order to use these data to develop a national estimate, Washington’s data were adjusted (for 

example, to exclude the weight of containers), as detailed in Appendix A. Table 17 presents 

Washington’s MSW and HHW data after these data refinements. 

Table 17. Total Leftover Paint in Washington: Adjusted Values 

Disposition Pathway (tons) 

Total Paint Refinements 

HSW in MSW Landfill 6,896 * excludes non-architectural paints 

* excludes container weight 

MRW Collection 3,254 * none made 

Total 10,150 NA 

Ongoing or Upcoming Studies 

Resources permitting, the Department of Ecology expects to conduct the next statewide waste 

composition analysis in 2007/2008, followed by the release of a report in 2009. 

Wisconsin 

Wisconsin conducted a statewide waste characterization study in 2002 to estimate the quantity 

and composition of waste disposed in the state’s MSW landfills. In addition, the Environmental 

Resources Center (ERC) located at University of Wisconsin-Madison, has compiled data for 

Wisconsin one-day HHW collection programs from 1984 to the present and permanent household 

collection programs since 1996. 

MSW - 2002 Wisconsin Statewide Waste Characterization Study 

As part of the statewide waste characterization study, waste loads at 14 of 36 active MSW landfills 

(comprising approximately 78 percent of all MSW disposed in the state) located in each of five 

21 
distinct geographic regions were randomly selected for sampling. Seasonal variations were 

accounted for by sampling half of the landfills in summer and half in winter; however, the results 

were presented as an aggregate for the entire year. Samples were first divided into three distinct 

substreams—residential, industrial/commercial/institutional (ICI), and construction and demolition 

(C&D) activities—and then further divided between commercially collected (including private and 

municipal haulers) and self-hauled waste loads. A total of 400 waste samples (116 residential, 166 

ICI, and 118 C&D) were taken from the selected loads and sorted into 64 distinct material 

categories. Waste tonnages were estimated for the individual landfills, and then composition 

estimates were calculated at a 90 percent confidence level for the state as a whole and the 5 

distinct geographic regions; for residential, ICI, and C&D generators; and for self-hauled and 

commercially collected wastes. Results from the 14 landfills were aggregated using a weighted 

averaging technique to develop a statewide estimate for the composition of disposed waste. Paint 

is characterized as either latex or oil paint. Paint quantities include the weight of the container if 

over 50 percent of the combined weight appeared to be from paint (liquid or dried) (Tarnecki, 

2006). Table 18 shows statewide estimates for total MSW, the HHW portion of that, and latex and 

oil paint waste for each waste sector (WI DNR, 2003). 

Table 18. Wisconsin Statewide Waste Characterization Study Results: 2002 

Sector (tons) 

Total MSW 

(tons) 

HHW 

(tons) 

Latex Paint 

(tons) 

Oil Paint 

(tons) 

Total Paint 

HHW (%) 

Percent of 

Residential 1,535,679 3,286 293 49 342 10.4 

Industrial/Commercial/ 

Institutional 2,100,198 15,524 1,028 411 1,439 93.0 

Construction & 

Demolition 1,116,341 7,345 5,667 635 6,302 85.5 

Total Waste 4,752,218 26,155 6,988 1,095 8,083 30.9 

Source: WI DNR, 2003 

Note: Latex paint is estimated to be 0.1 percent of total MSW, with 90 percent confidence that it is between 0.00 

and 0.3 percent. For oil paint, the study notes a 90 percent confidence interval, however because oil paint is a very 

small percentage of the total waste stream, and because numbers are rounded, the upper and lower confidence 

limits of the 90 percent confidence interval for oil paint are the same as the estimate. 

HHW – 2001 Wisconsin HHW Collection 

Wisconsin collects HHW through both permanent and one-day collection programs. Although the 

number of permanent programs has been growing since 1996, the number of one-day programs 

fluctuates annually based on funding. In 2001, there were 12 permanent programs and 9 one-day 

programs. ERC distributes annual surveys to collect data from these programs. For the 

permanent programs, the survey breaks down the waste by type (e.g., pesticides, latex paint, 

lead/oil paint, etc.); the one-day programs are only asked to report the total volume of HHW 

collected. The most recent year for which complete waste data are available for the permanent 

and one-day programs is 2001, with the exception of Milwaukee County, which is only complete to 

2000. Tables 19 and 20 show the HHW collection data by county for the permanent and one-day 

programs, respectively. 

22 
Table 19. Wisconsin HHW Collected by Permanent Programs: 2001 

County Total HHW 

(tons) 

Lead/Oil Paint 

(tons) 

Latex Paint 

(tons) 

Total Paint 

(tons) 

Percent of 

HHW (%) 

Brown 212.5 77.5 65.5 143.0 67 

Dane 230.0 59.4 105.4 164.8 72 

Kenosha 10.3 – – – – 

Marathon 19.9 – – – – 

Milwaukee (2000 data) 417.6 139.0 182.1 321.1 77 

NWRPC* 98.0 – – – – 

Oneida 32.2 – 19.2 19.2 60 

Ozaukee 11.0 – – – – 

Sheboygan 18.6 7.5 – 7.5 40 

Waukesha** 121.2 – – – – 

Waupaca 0.59 – – – – 

Winnebago 10.3 6.7 – 6.7 65 

Total 1,182.2 290.1 372.2 662.3 56 

Source: ERC, 2004

Note: Some counties did not report quantities of waste that was paint. 

*Northwest Regional Planning Commission (NWRPC) is a group of 10 counties that collect and report on 

HHW as a cooperative group. 

**Includes data for the Superior Emerald Park Landfill (SEPL), which is in Waukesha County but reported 

separately in 2001; these two facilities began reporting a combined value in 2003.

Table 20. Wisconsin HHW Collected by One-Day 

Programs: 2001 

County Total HHW (tons) 

Chippewa 16.5 

Eau Claire 24.8 

Green 11.9 

Iowa 3.3 

Langlade* 12.0 

Menominee 4.0 

Racine 3.5 

Trempeleau 2.0 

Washington* 5.2 

Total 83.2 

Source: ERC, 2004 

*These counties reported waste in pounds (6,618; 

7,304) and gallons (4,290; 775). The totals represent 

the (pounds + (gallons*4))/2000, assuming the gallon 

containers are half full. 

Of the 12 permanent programs, 10 reported that they collected lead/oil paint, but only 5 reported 

the quantities of lead/oil paint collected. Reporting on lead/oil paint quantities was more 

complete than for latex paint. Four of the permanent programs reported the quantity of latex 

paint collected. 

23 
The statistical method of ratio estimation was used in this report to estimate the total amount of 

paint that goes to HHW collection programs annually in Wisconsin. This uses the available data on 

paint quantities to scale up and provide a statewide estimate of paint waste. The total estimated 

amount of lead/oil paint was calculated by dividing the total weight of lead/oil paint collected by 

permanent programs by the total weight of HHW collected by permanent programs that reported a 

lead/oil paint quantity. This value was multiplied by the total HHW (permanent and one-day) 

collected in the state to provide an estimated volume of lead/oil paint that would be collected 

statewide: 

291 tons Pb/oil paint *(84 tons HHW + 1183 tons HHW) = 415 tons Pb/oil paint statewide 

889 tons HHW 

The same methodology was applied to estimate the volume of latex paint that would be collected 

statewide: 

372 tons latex paint * (84 tons HHW + 1183 tons HHW) = 528 tons latex paint statewide 

892 tons HHW 

This shows a total estimated weight of paint that would be collected by HHW programs annually to 

be 943 tons. This is the amount of paint projected to be collected statewide, for illustration 

purposes. However, the actual paint collected based on available county data is used in this 

analysis. 

Combined Paint Estimate: MSW and HHW 

The majority of the paint disposed of in Wisconsin (92 percent) goes to MSW landfills. 

Table 21. Total Leftover Paint in Wisconsin: Reported Data 

Disposition Pathway Total Paint (tons) Disposition Pathway (%) 

Percent of Paint by 

MSW Landfill 8,083 92 

HHW Collection 662* 8 

Total 8,745 100 

Sources: WI DNR, 2003; ERC, 2004

*Actual paint collected by permanent programs only.

In order to use these data to develop a national estimate, Wisconsin’s data were adjusted (for 

example, to exclude non-architectural paint), as detailed in Appendix A. Table 22 presents 

Wisconsin’s MSW and HHW data after these data refinements. 

24 
Table 22. Total Leftover Paint in Wisconsin: Adjusted Values 

Disposition Pathway 

MSW Landfill 

Total Paint 

(Tons) Refinements 

* excludes non-architectural paints 

* excludes container weight 

* adds back dried latex paint 

6,519 

HHW Collection 662* * none made 

Total 7,181 NA 

Sources: WI DNR, 2003; ERC, 2004

*Actual paint collected by permanent programs only.

Summary of State MSW Studies 

The state MSW composition studies used in this report rely on similar statistical sampling and 

sorting procedures and other similar methodological techniques to characterize the municipal 

solid waste stream. Thus, there is some methodological consistency among the studies. 

Similarities as well as differences in definitions, assumptions, and waste sorting procedures have 

been identified in this report and are summarized here. The differences have been carefully 

examined so that adjustments could be made for normalization across states. 

The table below summarizes the key differences and adjustments carried out to make the state 

MSW data comparable. For further detail, refer to Appendix A. For HHW, definitions and 

calculation methods were generally found to be comparable across state studies, with the 

exception of Iowa, which weighed bulk paint along with paint in containers. Consequently, Iowa 

was the only state where adjustments were made to HHW data, i.e., to exclude container weight. 

Table 23: Comparing State MSW Studies 

State 

Definition of 

“paint” includes 

latex & oil only? 

Yes 

Container weight 

included in “paint” 

weight? 

Yes: Adjusted 

(to exclude) 

Dried latex paint 

included in “paint” 

weight? 

No: Adjusted 

(to add-back) 

Non-Architectural 

paint included in 

“paint” weight? 

Yes: Adjusted 

(to exclude) California 

Iowa No: Adjusted 

(to exclude solvents) 

Yes: Adjusted 

(to exclude) Yes Yes: Adjusted (to exclude) 

Oregon No: Adjusted 

(to exclude thinners) 

Yes: Adjusted 

(to exclude) 

No: Adjusted 

(to add-back) 

Yes: Adjusted 

(to exclude) 

Washington Yes Yes: Adjusted 

(to exclude) Yes Yes: Adjusted (to exclude) 

Wisconsin Yes Yes: Adjusted 

(to exclude) 

No: Adjusted 

(to add-back) 

Yes: Adjusted 

(to exclude) 

25 
3. National Estimates of Paint Disposal

This section presents estimates of the total quantity of post-consumer architectural paint sent to 

municipal solid waste (MSW) landfills and incinerators, and collected by household hazardous 

waste (HHW) programs in the United States. National estimates have been derived based on data 

from the 5 states discussed in Section 2. The data from these states have been adjusted to 

account for three key factors (non-architectural paint, container weight, and dried latex paint), as 

discussed in detail in Appendix A. In addition to presenting national estimates of the total amount 

of post-consumer paint disposed of each year as MSW and HHW, this section also presents 

estimates of the relative proportion of the discarded paint that is latex versus oil-based. Finally, 

the quantity of paint disposed of each year is compared with the quantity of paint purchased. 

National estimates of the total quantity of paint disposed of each year can be derived in two 

ways: 

By using data from each state to individually project to national levels; or 

By combining data from all the states to generate a pooled estimate. 

The first method provides a broad range for the national estimate, based on data for each 

individual state. Each of the national estimates thus obtained assumes that the individual state 

estimate can be reasonably projected to the national level. However, states differ in 

characteristics that can impact the estimated totals. Thus, we also present a national estimate 

that pools the results for the five states. 

The following table presents estimates of the quantity of post-consumer paint disposed by state, 

based on MSW composition data, HHW collection data, and U.S. Census data on population (all 

ages included in the counts) and households, for each state and for the nation as a whole. Each 

state-level estimate is then extrapolated to the national level based on the state’s percentage of 

U.S. population and households. Similar estimates can also be based on sales of architectural 

coatings; however, state-specific architectural coatings sales data are not available, with the 

exception of the state of California. 

26 
Table 24. Estimated Quantity of Post-Consumer Architectural Paint Disposed Annually in the U.S. 

State 

Percent of U.S. 

(%) Disposed Within State 

(1,000 Gallons) 

Estimated Quantity of Paint 

Nationally (1,000 Gallons), 

Extrapolated Based On: 

Estimated Quantity of Paint Disposed 

Households 

[A] 

Population 

[B] 

Sales* 

[C] 

HHW 

Collection 

[D] 

MSW 

Disposed/ 

Incinerated 

[E] 

Total 

[F] 

Households 

[G] 

Population 

[H] 

Sales* 

[I] 

California 10.91 12.04 13.66 2,036 5,128 7,165 65,698 59,526 52,460 

Iowa 1.09 1.04 - 51 334 385 35,312 37,001 -

Oregon 1.26 1.22 - 303 518 821 64,896 67,495 -

Washington 2.15 2.09 - 728 1,426 2,154 100,042 102,859 -

Wisconsin 1.98 1.91 - 143 1,347 1,490 75,372 78,153 -

All States 

Combined 17.39 18.29 - 3,261 8,753 12,014 69,088 65,678 -

Calculations will not match due to rounding. 

Incorporates adjusted state data. 

Sources: U.S. Census Bureau, 2000(a); U.S. Census Bureau, 2000(b); CARB, 2003; CIWMB, 2004; data provided by Anna Ward, CIWMB, 

2004, IA DNR, 1998; data provided by Theresa Stiner, IA DNR, 2004; OR DEQ, 2002(a); data provided by Peter Spendelow, OR DEQ, 

2004(b); OR DEQ, 2002(b); WA ECY, 2003(a), and WA ECY, 2003(b). 

Notes: Paint quantities were converted from tons to gallons, assuming an average weight of 10.5 lbs/gallon for latex and 7.5 lbs/gallon 

for oil-based paint. 

Calculations: 

A. Based on 105 million households in the U.S. according to U.S. Census Bureau, 2000(a). 

B. Based on a population of 281 million in the U.S. according to U.S. Census Bureau, 2000(b). 

C. Based on architectural coatings sales of 661 million gallons in the U.S. according to U.S. Census Bureau data (derived, U.S. Census 

Bureau, 1994-2004). Sales data are not available, except for California, which is for 2000. 

D. Quantities of paint collected in HHW programs in this state (quantities were converted from tons to gallons assuming an average 

weight of 10.5 lbs/gallon for latex and 7.5 lbs/gallon for oil-based paint). 

E. Quantities of paint disposed of to landfills or incinerated in the state (quantities were converted from tons to gallons assuming an 

average weight of 10.5 lbs/gallon for latex and 7.5 lbs/gallon for oil-based paint). 

F. Combines paint collected from HHW programs and landfills. 

G. National estimate of the quantity of leftover paint extrapolating by percent of households in the state: [F]/[A] 

H. National estimate of the quantity of leftover paint extrapolating by percent of population in the state: [F]/[B] 

I. National estimate of the quantity of leftover paint extrapolating by percent of architectural coatings sales in California: [F]/[C]. 

*Architectural coatings sales data are not available, except for California, which is for 2000. 

As shown above, when considering each individual state’s projection to the national level, the 

estimated quantity of post-consumer architectural paint disposed of annually in the U.S. ranges 

between 35 million and 103 million gallons. The pooled estimate provides an estimate of 66 to 69 

million gallons of post-consumer architectural paint disposed or incinerated annually in the U.S. 

According to the U.S. Census Bureau, architectural paint sales in the U.S. (for data collection and 

sampling years included in this analysis) ranged from 621 to 809 million gallons. (U.S. Census 

Bureau, 1994-2004). Using sales data for the year in which the underlying MSW and HHW data 

were collected for each of the national estimates of paint disposal reflected in Table 24,(and an 

average if multiple years were used), the total quantity of post-consumer architectural paint 

disposed was calculated as a percentage of annual architectural paint sales. As presented in 

Table 25, the annual quantity of architectural paint disposed in the U.S. is estimated to be 

27 
approximately 6 to 16 percent of annual sales, based on the projection of the individual statelevel estimates to the national level or a pooled estimate of around 10 percent. 

Table 25. Percent of Architectural Paint Sold in the U.S. that is Disposed 

State 

Percent based on: 

Households Population Sales* 

California 9.4 8.5 7.5 

Iowa 5.7 6.0 

Oregon 9.9 10.3 

Washington 15.2 15.6 

Wisconsin 11.1 11.5 

All States Combined 10.4 9.9 

Sources: U.S. Census Bureau, 2000(a); U.S. Census Bureau , 2000(b); CARB, 2003; 

CIWMB, 2004; data provided by Anna Ward, CIWMB, 2004, IA DNR, 1998; data 

provided by Theresa Stiner, IA DNR, 2004; OR DEQ, 2002(a); OR DEQ, 2002(b); 

data provided by Peter Spendelow, OR DEQ, 2004(b); WA ECY, 2003(a), and WA 

ECY, 2003(b). 

* Architectural coatings sales data not available by state, except for California. 

California’s architectural coatings sales data are for 2000. 

Alternative Estimation Methods 

Using the same data, this section presents two alternative methods for estimating the total 

quantity of post-consumer architectural paint sent to MSW landfills and incinerators, and collected 

by HHW programs in the U.S. In the first method, household data are used to estimate the 

quantity of paint disposed annually in the U.S., based on a pooling of the estimates developed for 

the 5 states. The second method uses population data to determine the same. 

Table 26A presents the ratio of the total amount of architectural paint that is disposed of as MSW 

or HHW in the 5 states to the total number of households in these jurisdictions. This ratio (0.65 

gallons per household) is then applied to the total number of households in the U.S. (105 million 

households (U.S. Census Bureau, 2000(a))), resulting in a national estimate of 69 million gallons of 

post-consumer architectural paint disposed annually. 

28 
Table 26A. Gallons of Architectural Paint Disposed Annually Per Household for Five States 

(Based on the total number of households) 

State (1,000s) 

Number of Households 

(1,000 Gallons) 

Total Leftover Paint 

Household

Gallons per 

California 11,503 7,163 0.62

 Iowa 1,149 385 0.34

 Oregon 1,334 821 0.62

 Washington 2,271 2,155 0.95

 Wisconsin 2,085 1,491 0.72

 All Five States 18,342 12,014 0.65 

Sources: U.S. Census Bureau, 2000(a); CIWMB, 2004; data provided by Anna Ward, CIWMB, 2004, IA 

DNR, 1998; data provided by Theresa Stiner, IA DNR, 2004; OR DEQ, 2002; data provided by Peter 

Spendelow, OR DEQ, 2004(b); WA ECY, 2003(a), and WA ECY, 2003(b). 

Similarly, Table 26B presents the ratio of the total amount of paint disposed in the 5 states to the 

total population (all ages included7) in these states. This pooled ratio (0.23 gallons per person) is 

then applied to the total U.S. population (281 million people (U.S. Census Bureau, 2000(b))), 

resulting in a national estimate of 65 million gallons of post-consumer architectural paint disposed 

annually. 

Table 26B. Gallons of Architectural Paint Disposed Annually Per Person for Five States (Based on 

the total population) 

State 

California 

Population 

(1,000s) 

33,872 

Total Leftover Paint 

(1,000 Gallons) 

7,163 

Gallons per Person

0.21

 Iowa 2,926 385 0.13

 Oregon 3,421 821 0.24

 Washington 5,894 2,155 0.37

 Wisconsin 5,364 1,491 0.28

 All Five States 51,477 12,014 0.23 

Sources: U.S. Census Bureau, 2000(b); CIWMB, 2004; data provided by Anna Ward, CIWMB, 2004, IA DNR, 

1998; data provided by Theresa Stiner, IA DNR, 2004; OR DEQ, 2002; data provided by Peter Spendelow, OR 

DEQ, 2004(b); WA ECY, 2003(a), and WA ECY, 2003(b). 

As was done previously in Table 25, we can compare these two national estimates of the amount 

of post-consumer architectural paint disposed annually to the amount of paint annually sold in the 

U.S. According to numbers from the U.S. Census Bureau, the estimated total quantity of 

architectural coatings sold in the U.S. (averaged over the different study years used for the 5 

7

 Another approach would be to use the population age 18 years and older to better reflect the 

population using paint. 

29 
states) was 662 million gallons (derived, U.S. Census Bureau, 1994-2004). Table 27 shows that 

around 10 percent of this can be estimated to be disposed annually, within the range presented in 

Table 25. 

Table 27. Percent of Architectural Paint Sold in the U.S. that is Disposed 

Quantity of Architectural 

Paint Sold in the U.S.* 

(1,000 Gallons) 

Avg. Annual Estimated Annual Quantity of 

Architectural Paint Disposed in the 

U.S. (1,000 Gallons), based on: 

Quantity of Architectural Paint 

Disposed Annually as a Percent 

of Sales (%) 

661,790 

Household 69,088 10.4 

Population 65,678 9.9 

Source: U.S. Census Bureau 

* Averaged over the different study years used for each of the 5 states. 

National Estimate Compared with PPSI Estimate 

The PPSI Background Report provided an estimate of the quantity of leftover paint generated 

annually in the U.S., based on data from California HHW and Washington MRW (HHW) collection 

programs, as well as U.S. Census data on population and households in each of the two states and 

the country as a whole, and an estimate of the percent of the population served by permanent or 

temporary HHW or MRW collection programs in the two states. The estimate was based on the 

assumption that existing HHW programs in the two states were collecting between 50 and 100 

percent of leftover paint generated by residents served by those programs. The PPSI Background 

Report estimated the quantity of leftover paint generated in the U.S. to be in the range of 16 

million to 35 million gallons per year, or 2.5 to 5 percent of annual paint sales (PPSI 2004a). 

The national estimates presented in this report refine the estimate provided in the PPSI 

Background Report by: 

Incorporating HHW collection data from three additional states (Iowa, Oregon and Wisconsin); 

Estimating the actual quantity of paint collected by HHW programs and disposed via the MSW 

waste stream 

30 
4. Conclusions 

From the data examined in this report, it is estimated that when considering each of five 

individual state’s projections to the national level, between 35 and 103 million gallons of postconsumer architectural paint (or between 6 and 16 percent of annual sales) is disposed of 

annually. Further, based on a pooled estimate of these five states, 66 to 69 million gallons of 

architectural paint are estimated to be disposed of each year. These quantities may not 

represent all of the leftover paint generated annually in the U.S. Some leftover paint is 

undoubtedly dried out by consumers outside of the original container, spilled down drains, or 

disposed of by contractors and large industrial, commercial and institutional users as solid or 

hazardous waste. On the other hand, there are also factors that may lead to over-estimation of 

the amount of leftover paint disposed annually. In addition, the estimates presented in this 

report do not account for the large quantity of leftover paint that is currently stockpiled in 

homes, nor do t hey provide a basis for determining if that stockpile is increasing or diminishing 

over time. 

Nevertheless, these estimates may provide a useful measure of the total quantity of postconsumer architectural paint disposed in the U.S. each year, and a rough approximation of the 

percentage of paint sold each year that becomes leftover post-consumer waste. 

31 
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2004. 

Association of Municipal Recycling Coordinators (AMRC), 2005. Household Hazardous Waste Baseline 

Composition Study, 2004. Accessed: http://www.productcare.org/documents/ON2004Study.pdf 

California Integrated Waste Management Board (CIWMB), 2001. California Integrated Waste 

Management Board, Board Meeting January 23-24, 2001. Agenda Item 23. Accessed: 

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California Air Resource Board (CARB), 2003. 2001 Architectural Coatings Survey Final Report. 

Chamberlain, Mary, R.W. Beck Consulting, 2006. Personal communication with Amanda Morris on June 

19, 2006. 

CIWMB, 1999. 1999 California Statewide Waste Characterization Study. Accessed: 

http://www.ciwmb.ca.gov/Publications/LocalAsst/34000009.doc 

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CIWMB, 2004. 2004 California Statewide Waste Disposal Characterization Study. Accessed: 

http://www.ciwmb.ca.gov/Publications/LocalAsst/34004005.doc 

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19, 2004. 

Environment Canada (EC), 2002. Extended Producer Responsibility & Stewardship: An Inventory of 

Waste Diversion Programs in Canada. Accessed: 

http://www.ec.gc.ca/epr/inventory/en/DetailView.cfm?intInitiative=55 

Environmental Resources Center (ERC) Wisconsin Hazardous Waste Collection Programs-featuring 

households and very small quantity generators. Accessed: http://www.uwex.edu/erc/hazwste.html 

Hlavka, Rick, Green Solutions, 2006. Personal Communication with Jocelyn Siegel on June 20, 2006. 

Iowa Department of Natural Resources (IA DNR), 1998. Iowa Solid Waste Characterization. Accessed: 

http://www.iowadnr.com/waste/sw/files/charstudy.pdf 

Kish, Leslie. 1965. Survey Sampling, John Wiley and Sons: New York. 

Minnesota Solid Waste Management Coordinating Board (MN SWMCB), 2000. Statewide MSW 

Composition Study – A Study of Discards in the State of Minnesota. Accessed: 

http://www.moea.state.mn.us/publications/wastesort2000.pdf 

National Family Opinion Research, Inc. (NFO), 1995. Consumer Architectural Coatings Disposal Study. 

National Paints and Coatings Institute, 2004. 2001 Sales of Architectural Paint. Accessed: 

http://www.paint.org/ind_info/ffarch.cfm 

Nogas, Sue, U.S. EPA, 2004. Personal communication with Anna Leos-Urbel on May 20, 2004. 

Oregon Department of Environmental Quality (OR DEQ), 2000. Waste Characterization and Composition 

2000 Report. Accessed: http://www.deq.state.or.us/wmc/solwaste/wcrep/wcrep2002.htm 

Oregon Department of Environmental Quality (OR DEQ), 2002(a). Waste Characterization and 

Composition 2002 Report. Accessed: 

http://www.deq.state.or.us/wmc/solwaste/wcrep/wccr2002.htm 

32 
Oregon Department of Environmental Quality (OR DEQ) 2002(b). 2002 Oregon Recovery and Waste 

Generation Rates Report. Accessed: 

http://www.deq.state.or.us/wmc/solwaste/documents/2002MRSReport.pdf 

Pennsylvania Department of Environmental Protection (PA DEP), 2003. Statewide Waste Composition 

Study. Accessed: 

http://www.dep.state.pa.us/dep/deputate/airwaste/wm/recycle/Waste_Comp/Study.htm 

Product Stewardship Institute (PPSI), 2004a. Paint Product Stewardship: A Background Report for the 

National Dialogue on Paint Product Stewardship. Accessed: 

http://www.productstewardship.us/supportingdocs/DialoguePaintPS.doc 

Product Stewardship Institute (PPSI), 2004b. National Paint Infrastructure Collection System Modeling 

Executive Summary - DRAFT. Accessed: 

http://www.productstewardship.us/supportingdocs/CollecMdlsWtPaper41304.doc 

Quinn, Jim, Hazardous Waste Program Manager, Portland Metro, 2004. Personal communication with 

Jocelyn Siegel and Barry Elman on July 29, 2004. 

Spendelow, Peter, Oregon Department of Environmental Quality, 2004(a). Personal communication 

with Gaytri Bhatia, September 2004. 

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with Gaytri Bhatia, December 2004. 

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with Gaytri Bhatia, April 2006. 

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with Jocelyn Siegel, July 2006. 

State Library of Iowa, 2004. Iowa Census Data Tables: Counties. Accessed: 

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000.pdf 

Stiner, Theresa, Iowa Department of Natural Resources, 2004. Personal communication with Anna 

Leos-Urbel on June 24, 2004. 

Tarnecki, Tanya, Cascadia Consulting Group, 2004. Personal communication with Anna Leos-Urbel on 

June 2, 2004. 

Tarnecki, Tanya, Cascadia Consulting Group, 2006. Personal communication with Jocelyn Siegel on 

July 7, 2006. 

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Characteristics. Accessed: http://factfinder.census.gov 

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Accessed: http://factfinder.census.gov 

United States Census Bureau, Current Industrial Reports, Paint and Allied Products: 2003.. November 

2004. Accessed: http://www.census.gov/industry/1/ma325f03.pdf 

United States Census Bureau, Current Industrial Reports, Paint and Allied Products: 2004. September 

2005. Accessed: http://www.census.gov/industry/1/ma325f04.pdf 

United States Environmental Protection Agency (U.S. EPA), 2001. Municipal Solid Waste in the United 

States – 2001 Facts and Figures. Accessed: http://www.epa.gov/epaoswer/nonhw/muncpl/msw99.htm#links 

Ward, Anna, CIWMB, 2004. Personal communication with Anna Leos-Urbel on May 26, 2004. 

33 
Washington Department of Ecology (WA ECY), 2003(a). Solid Waste in Washington State, Twelfth 

Annual Status Report. Accessed: http://www.ecy.wa.gov/pubs/0307019.pdf 

Washington Department of Ecology (WA ECY), 2003(b). Waste Composition Analysis for the State of 

Washington. (Prepared by Green Solutions). Accessed: 

http://www.rcap.org/swp/docs/Recycling/WaStateWasteComp.pdf 

Washington Department of Ecology (WA ECY), 1992. Combined WGA Material Type Summary for 

Washington State. Accessed: http://www.ecy.wa.gov/programs/swfa/solidwastedata/waste.asp 

Wisconsin Department of Natural Resources (WI DNR), 2002. Wisconsin Statewide Waste 

Characterization Study Summary 2002. Accessed: 

http://www.dnr.state.wi.us/org/aw/wm/publications/recycle/wrws-finalrpt.pdf 

34 
Appendix A: Data Refinements and Other 

Considerations 

In conducting the analysis presented in this report, numerous factors were identified that could 

affect the results. This Appendix describes these factors and, where quantitative adjustments 

were made to the results, describes the methodology for doing so. 

Data Refinements 

The national estimates presented in this report are based on data pertaining to the disposal of 

architectural latex and oil-based paint in the municipal solid waste stream, as well as data 

collected by household hazardous waste collection centers, as reported in studies from five states 

across the country. In combining individual state-level data sets to develop a national estimate, 

similarities and differences in definitions, assumptions, and data collection methodologies were 

examined to determine their possible effect on the results, and adjustments were made to the 

data when warranted. For example, the paint quantities reflected within some state MSW 

composition studies excluded the quantity of dried paint in containers that was sorted into a nonpaint category, or included the weight of the container with the paint weight. Adjustments were 

made to the results of these studies, where possible, to address such issues. This report assumes 

that household behavioral patterns associated with stockpiling and disposing of leftover paint are 

relatively consistent across the U.S. and so adjustments are not made for this variable. This 

section details all adjustments made to the state data in the course of developing the national 

estimates. 

MSW Data Refinements. The various state MSW composition studies generally have 

consistent methodologies (as presented in the Other Considerations section below), but also 

present some measurable differences. For example, some studies include other materials such as 

solvents or thinners in their definition of “paint.” Consequently, adjustments were made using 

the best obtainable data to make these studies more comparable before combining their data for 

the national estimate. Adjustments to MSW data are especially important as, from the available 

state data, it is apparent that paint in the MSW stream accounts for the majority of leftover paint. 

HHW Data Refinements. In general, the five states analyzed have mature HHW collection 

programs that compile reliable data on the quantity of paint collected. 

Definition of “paint” 

The goal of this study was to examine latex and oil paint. However, some states may also include 

other materials in their definition of “paint.” 

35 
 In HHW collection efforts Washington includes contaminated latex paint (such as latex paint 

mixed with solvents, oil-based paints, dirt or garbage). Additionally, some HHW studies may record 

“paint” differently based on the available categories listed on data sheets. However, these factors 

were not expected to have a major impact on the results of this study, and data were not adjusted 

due to insufficient additional information. 

In state MSW studies, two states explicitly included other materials in the paint category during 

their waste sorts: Iowa quantified “paints and solvents,” and Oregon quantified “oil paint and 

thinners.” In addition to these known factors, factors such as personal interpretation by the 

sorting crew could potentially make the categories different in ways that are not easy to detect. 

In Oregon and Iowa adjustments were made based on estimates of the portion of the combined 

categories that were paint. 

In addition, the Association of Municipal Recycling Coordinators (AMRC)’s 2005 HHW Baseline 

Study (conducted in Ontario Canada), indicates that latex and oil-based paint categories may also 

include quantities of other materials. For example, the “latex paint” category also includes stain, 

rust or metal paint, specialty paints, liquid plastic, and varnish. Similarly, the “oil-based paint” 

category includes other product types, such as: stain, driveway sealer, varnish, wood finish, and 

lacquer. Since sufficient data on the potential mix of materials in each paint category does not 

exist, with the exception of the adjustments detailed below, this analysis assumes that one 

hundred percent of the paint in the latex category is latex paint, and the same for the oil-based 

category. 

Adjustments made: 

� Iowa – excluded 10 percent (solvents)8 from the total tons of paints and solvents in MSW (IA 

DNR, 1998). 

� Oregon - excluded 5 percent (thinners)9 from the total tons of oil paint and thinners in MSW 

(averaged, OR DEQ, 2000 and 2002(a)). 

Architectural vs. Non-Architectural Paint 

The goal of this study was to estimate national quantities of architectural paint disposed, defined 

as paint used in and on buildings. However, all statewide MSW studies used in this analysis 

included both architectural and non-architectural paint in their “paint” category. From AMRC’s 

2005 Baseline Study, it was determined that, on average, 12 percent of the waste “paint” is 

comprised of non-architectural paint types. Specifically, the latex paint category was found to 

include 4 percent non-architectural products, while 27 percent of oil-based paints included nonarchitectural products. For the purposes of this analysis, each state’s data was adjusted to 

exclude non-architectural paint, as presented below. 

8

 Based on conversations and data provided by Tanya Tarnecki of Cascadia Consulting, and Brad 

Anderson of Sky Valley Associates. 

9

 Per Brad Anderson, Sky Valley Associates, August 10, 2006. 

36
Adjustments made: 

� California, Iowa, Oregon, Washington, and Wisconsin – excluded 4 percent (non-architectural 

latex paints) from the total tons of latex paint and 27 percent (non-architectural oil-based 

paints) from the total tons of oil-based paint in MSW. 

Paint Weight 

Research indicates that the waste sorting protocols used in most waste characterization studies 

call for distinguishing between: 

empty paint containers (which are typically classified as the material of the container itself); 

containers containing dried paint (which are typically classified as the material of the 

container or as a mixed material category); and 

containers containing liquid paint (which are typically classified as paint). 

This leads to two factors for consideration: 

whether dried paint is included in the overall paint estimate; and 

whether the weight of the container is included in the overall paint estimate. 

Dried Paint Weight 

Most states do not include dried paint in their “paint” category10. Several studies indicate that 

increasingly, consumers are drying latex paint prior to disposal. It is important to understand the 

impact of dried paint on a national estimate. To do this, we considered three sources of 

information that indicate a substantial portion of dried paint can be expected in disposed 

containers. 

Many states and/or local communities advise their residents to dry out their leftover latex 

paint for disposal in the garbage or at a collection center. Even states like California that do not 

encourage this practice, nevertheless permit residents to dispose of dried latex paint in the MSW 

stream. Organizations such as the National Paint and Coatings Association (NPCA) also promote this 

approach. For example, NPCA’s Six Point Program for Leftover Paints advises consumers to 

properly dispose of latex paint by drying it (as a last resort after reusing, recycling, and exchanging 

leftover paint). (NPCA 2004b). 

A survey conducted for NPCA in the mid 1990s sought to learn about the disposition of leftover 

paint, stain, thinners and similar materials in households. The survey was conducted in 1,000 

households, by a national market research firm, National Family Opinion (NFO) using their 

10 Washington does include dried paint and Wisconsin includes dried oil-based paint only. 

37 
nonprobability consumer panel sample. The study had an interview response rate of more than 70 

percent. The study reported that, on a volume basis, 30 percent of leftover paint was from homes 

that use evaporation as a disposal method. (The survey did not ask the respondents to differentiate 

between latex and oil-based paint.) (NFO, 1995).

 The two Oregon waste characterization studies (2000 and 2002) included an analysis of 

contaminants in disposed waste. For this analysis, paint containers that were nearly empty or 

contained dried paint were included in the appropriate container category – non-food steel cans, 

rigid plastic containers, or mixed material – and then subject to contamination analysis. Paint 

found in these containers was scraped out, weighed, and then “added back” to the paint category. 

The amount of dried latex paint found in containers was fairly large, so a correction factor was 

produced. The Oregon contamination analysis provided the following results for 4 detailed samples 

containing paint in 2002 and 2 samples in 2000. It should be noted that this study alone does not 

constitute conclusive evidence regarding the quantity of dried paint that is disposed in containers 

in MSW, since it is based on a limited sample size. However, it does provide supporting evidence 

that a significant quantity of leftover paint may be dried out by the consumer prior to disposal in 

MSW. In addition, it suggests that a substantial percentage of latex paint is dried out prior to 

disposal in landfills and incinerators, but the percentage of oil-based paint that is dried out is 

negligible. 

Table 28. Oregon contamination analysis in 2000 and 2002 

# Samples Percent of Dry 

Add-Backs 

Contamination 

Correction Factor (%) 

90% Confidence 

Intervals 

Avg. 

Contamination 

Correction 

Factor (%) 2000 2002 2000 2002 2000 2002 2000 2002 

Latex paint 1 3 30.40 20.50 30.40 20.45 (-12.75 to 

78.53) 

(2.65 to 

51.26) 25.4 

Oil-based 

paint/thinner 1 1 4.40 4.50 4.37 4.52 (0.00 to 8.25) 

(0.47 to 

10.97) 4.5 

Source: OR DEQ, 2000 and 2002 

It should be noted that despite the small sample sizes and large confidence intervals for latex 

paint, the two individual analyses present fairly consistent results. 

The NPCA study suggests that about 30 percent of leftover paint may be dried out prior to 

disposal, and therefore would not be reflected in the paint quantity estimates developed by state 

waste composition studies. In order to fully capture the quantities of paint disposed, dried paint 

may be “added back” to these paint quantities. Because guidance to consumers to dry out paint 

only applies to latex paint, and considering that the Oregon contamination analyses show far more 

dried latex than dried oil-based paint in cans, the latex paint quantities in three state MSW 

studies were adjusted upward by 30 percent, while the oil-based paint quantities were left as-is. 

This adjustment does not factor in the following considerations, which are not resolvable due to 

the lack of data: 

38 
Weight of dried paint reported in the Oregon contamination analyses does not represent the 

original weight of the paint as a liquid. 

Consumers may be drying paint and disposing of it outside of containers. 

Adjustments made: 

� California, Oregon, and Wisconsin – added-back 30 percent (dried paint) to the total tons of 

latex paint in MSW. 

Residual (Liquid) Paint Weight 

Residual amounts of liquid paint in a container are categorized in some waste composition studies 

as mixed materials or the material of the container itself rather than as paint. The amount 

considered residual is subject to interpretation by the sorting crew, since most states have no 

definitive threshold. Waste composition study experts indicate that a container is categorized as 

“paint” if it contains any liquid paint (with the exception of Washington and Wisconsin, which 

categorize a container as “paint” when paint accounts for the majority of the combined container 

and paint weight). Because these distinctions in classification could not be quantified, residual 

liquid paint quantities in disposed containers are considered negligible and no adjustments were 

made. 

Container Weight 

Inclusion of container weight with paint weight was also considered in this analysis. For MSW, 

once a container is classified as “paint,” the paint and its container are weighed and recorded 

within this category. The weight of the container therefore should be excluded from the paint 

quantities in order to develop a more accurate estimate. Detailed analyses documenting the type 

and size of container were not undertaken at this time. However, we look at the following studies 

to determine the portion of weight that is container alone: 

An expert at Portland Metro11 estimates that an average gallon paint container weighs 0.9 

pounds, with gallon containers being the most common size. They further estimate that latex 

paint weighs between 10-11 pounds per gallon and oil-based paint weighs between 7-8 pounds 

per gallon, and that paint cans come into their HHW collection program, on average, 45 

percent full. 

Product Care in British Columbia, Canada, estimates that approximately 20-25 percent of 

the combined weight of the paint and containers it collects can be attributed to the 

containers. From these data, and given the weight of paint above, we estimate that on 

average containers in this program are 21 percent full. 

11 Based on conversations and data provided by Jim Quinn of Portland Metro. 

39 
The AMRC 2005 Baseline Study presents data on container quantity and residual paint 

quantities for oil and latex paints. From these data we estimate that latex and oil-based paint 

containers are 51 percent full. 

It should be recognized, however, that paint containers collected by HHW programs might contain 

more paint, on average, than containers disposed in MSW landfills, although this has not been 

formally examined. As the amount of paint in a container decreases, the weight of the container, 

relative to that of its contents, increases. Due to the lack of hard evidence comparing the 

relative fullness of paint containers in HHW and MSW programs, this analysis assumes that 

containers in the MSW stream are half the fullness of those collected at HHW collection centers. 

Thus, averaging Portland Metro, Product Care, and AMRC’s estimates on container fullness and 

assuming half this fullness for MSW, we estimate that 32 percent of the combined weight of the 

paint and containers can be attributed to the containers themselves and should be “backed out” 

from the overall paint weight. 

In addition, it was learned that a portion of the paint coming to Iowa’s HHW collection center was 

not bulked prior to weighing, thereby including the weight of the container. By averaging the 

estimates on container fullness from the above-mentioned studies, we estimate that 19 percent of 

the combined weight of the HHW paint and containers can be attributed to the containers 

themselves and should also be “backed out” from the overall paint weight. 

Adjustments made: 

� California, Iowa, Oregon, Washington, and Wisconsin – excluded 32 percent (container weight) 

from the total tons of MSW paint estimates. 

� Iowa – excluded 19 percent (container weight) from the 57 tons of HHW paint known to include 

container weight. 

Other Considerations 

Paint Spillage 

Paint may spill from containers en route to the disposal location, where it is subsequently 

weighed. The loss of paint (presumably adhered to paper, food and other adjacent waste 

materials) would be reflected in an undercount of total paint at the disposal site. It is safe to 

assume that some cans may get crushed on the way to the landfill, and that lids may pop off. Per 

Brad Anderson, a consultant with Sky Valley Associates, approximately 1 percent of their waste 

characterization samples showed spilled paint, suggesting that spilled paint quantities are small. 

Sky Valley Associates does not quantify the percentage of paint containers that arrive with open 

lids. 

40 
Seasonal Collection Efforts 

State waste composition studies sometimes conduct sampling of MSW during different times of the 

year, such as in a cold and warm seasons. In the 2002 Oregon Solid Waste Characterization and 

Composition Study, samples collected during four seasons present little to no variability in the 

overall results based on season. In the 2005 Iowa Study, IDNR also concluded that seasonal 

differences in the MSW stream are not statistically significant due to minimal difference observed 

from their seasonal waste sort in the 1998 study. 

Paint Disposition/Management 

Some of the states included in this analysis have incinerators or waste-to-energy facilities, where 

amounts of paint, along with other MSW, are sent for energy recovery. The paint quantity data 

reflected in the state MSW case studies includes these quantities. 

Paint Misclassification 

The misclassification of unknown paint or solvents is another factor that can lead to errors in the 

estimation of paint in waste composition studies. For example, a waste sorter might categorize 

an unlabeled container of paints or solvents as “unknown,” or define other liquids (for example, 

solvents) as “paint.” Factors such as personal interpretation by the sorting crew could potentially 

make the categories different in ways that are not easy to detect. This could lead to over- or 

under-estimation of the amount of paint being disposed. 

Sample Size, Confidence Intervals, and Bias 

Sampling variance of the state estimates can be influenced by sample sizes, sampling weights, and 

measurement protocols (for example, random versus nonrandom sampling). Sample size (for 

example, 100 versus 10 samples) directly impacts the precision of the state estimates, with a 

larger number of samples yielding more statistically robust results. In addition, results could be 

biased if states ignored the sampling weights in forming their estimates. The actual measurement 

protocols used within each state can also have an impact of the error of the state estimates (as 

discussed under Paint Misclassification). 

41