Formaldehyde and Indoor Air Quality

Written by:Alexander Harris

Sankaranarayanan Ravichandran

University of Colorado-Boulder

CVEN4554/5554Fall 2015

December 10, 2015

Introduction

In its pure form, formaldehyde is a colorless gas with a pungent smell that can

cause negative health effects to humans and animals. The chemical is commonly found

in resins for the manufacturing of composite wood products (i.e., hardwood plywood,

particleboard, and medium density fiberboard), building materials, household products,

preservatives in cosmetics, fertilizers, and combustion by-products (“Formaldehyde

Emission Standards for Composite Wood Products”, 2015). Formaldehyde is a known

human carcinogen and for this reason it has been of abundant concern in terms of air

quality since under certain conditions, it can be released from these manufactured

products over long periods of time via diffusion, decomposition, or degradation (NTP,

2011).

When discussing formaldehyde, it is important to devote great attention to

indoor air quality as an average person spends 87% of their day in indoor environments

(Klepeis et al., 2001). Increased formaldehyde concentrations indoors can magnify

existing respiratory conditions and cause respiratory distress for others. For example,

in 2001 a research team from the University of Western Australia identified a

correlation between indoor formaldehyde levels and increased instances of asthma

(Rumchev et al., 2002). In addition to people with respiratory illnesses, it’s expected

that formaldehyde would affect other vulnerable groups of people, such as children and

the elderly. Exposure to formaldehyde at a young age has the potential to impact their

health negatively in the later part of their lives. In the case of the elderly, symptoms that

would normally cause mild irritation to a healthy adult could take a more serious toll on

older and weaker individuals.

The indoor environment can also play an important role in formaldehyde

emissions. The air tight nature of buildings, temperature and ventilation rates influence

formaldehyde emissions. Researchers Aydogan and Montoya further state that the

increasing trend of isolating indoor environments to save energy required for climate

control further increases formaldehyde concentrations (Aydogan and Montoya 2011).

Relationships between indoor environments and formaldehyde emissions, as well as,

strategies for mitigating emissions from flooring materials will be discussed in this

report.

Regulating Formaldehyde

With increased understanding of the negative health effects from formaldehyde

emissions over the years, domestic and international air quality governing agencies

focused their efforts on reducing emissions. The Housing and Urban Development

Agency (HUD) enacted the United States’ first regulation imposing restrictions on

formaldehyde emissions from wood composite products for manufactured houses in

1985 (Ruffing et al., 2009). Unfortunately HUD’s legislation did not apply to all wood

products with high levels of formaldehyde. Nearly 25 years later in 2009, the California

Air Resources Board (CARB) passed more aggressive legislation to limit formaldehyde

emissions from wood building materials sold in California (Ruffing et al., 2009). The

regulations were implemented in two phases, the first in 2009 and the more restrictive

phase two took effect between 2010 and 2012.

Although the Environmental Protection Agency (EPA) is currently finalizing regulations

that would essentially expand the CARB standards to cover all 50 states, it is concerning

that in 2015 the U.S. federal government has not yet implemented uniform regulations

on indoor formaldehyde emissions in the United States (“Formaldehyde Emission

Standards for Composite Wood Products”, 2015). Additionally, outside of the US, the

European Union, China, Japan, and South Korea have recently enacted regulations

limiting formaldehyde emissions in consumer products (Ruffing et al., 2009; Kim and

Hyun-Joong, 2005). See Table 1 for current CARB-Phase 1&2 and current European E1

standards on formaldehyde emissions in parts per million (ppm) (Salem et al., 2012).

Product CARB-Phase 1 CARB-Phase 2 E1

Hardwood Plywood 0.08 ppm 0.05 ppm0.10 ppm

(0.12 mg/m3)Particleboard 0.18 ppm 0.09 ppm

Medium-Density Fiberboard 0.21 ppm 0.11 ppm

Table 1: CARB and E1 formaldehyde emissions standards

Lumber Liquidators: A Case Study

In order to understand the seriousness of formaldehyde emissions and the need

for uniform regulations across the United States, one can look to the recent news

regarding floor laminates sold by Lumber liquidators Inc. On March 1, 2015, the CBS

Corporation, through its television program 60 Minutes, claimed that the China-made

floor laminates sold by Lumber Liquidators Inc. in the state of California did not meet

formaldehyde emission standards set by the CARB and contained dangerous levels of

formaldehyde. It was further claimed that the product sold was labelled to indicate that

it met California’s formaldehyde standards for flooring, CARB 2 compliant.

As part of 60 Minutes’ initial investigation, 150 boxes of laminate flooring were

purchased in California and tested in three certified labs for CARB 2 compliance. The

results showed that all 150 boxes failed to meet CARB emission standards, with some

even exceeding emission levels by twenty times the legal limit. 60 Minutes then

proceeded with another investigation to ensure their claims. They purchased an

additional 31 samples from Lumber Liquidator’s Inc. stores in Virginia, Florida, Texas,

Illinois, and New York. Only one of these sample were found to meet California emission

standards via the California Department of Public Health (CDPH) test. According to 60

Minutes, the results obtained from these tests showed that the formaldehyde emissions

from the flooring product would result in an indoor air quality environment deemed as

"polluted indoor environment" by the EPA. The results imply that Lumber Liquidators

Inc. violated California state law by selling these products. The 60 Minutes report also

stated that the flooring that failed these tests were manufactured in China and similar

products sold by competitors of Lumber Liquidators Inc. were not in violation of

permissible standards. (“Lumber Liquidators Class Action…”, 2015). Lumber

Liquidators' founder and former chief executive officer (CEO), Thomas Sullivan has

disputed the claims made and has questioned the methodology used to carry out the

tests. Mr. Sullivan was replaced as CEO by John M. Presley as of November 16, 2015.

It’s interesting to know that 60 Minutes had different tests conducted on the

different samples, specifically CARB and CDPH testing procedures. CARB has published

standard operating procedures for testing formaldehyde emissions from finished goods.

Their CARB 2 formaldehyde emission test involves the destruction or removal of the

surface layer in order to gather reliable data, however, this test would likely show

elevated levels formaldehyde since the surface layer acts as a sealant, which will be

addressed in the Formaldehyde Source Controls section of this report. Contrary to CARB

testing, the CDPH method is nonintrusive and measures the formaldehyde

concentrations coming from laminates in a home via a test kit (“Standard Operating

Procedure…”, 2013).

As of today, there are over 100 lawsuits filed against Lumber Liquidators Inc. for

selling laminate flooring with excessive levels of formaldehyde. The lawsuits are

currently with the U.S. District Court for the Eastern District of Virginia (“Lumber

Liquidators Class Action…”, 2015).

Formaldehyde in Wood Flooring

Formaldehyde’s prevalence in wood-based products, especially engineered

flooring, correlates to higher formaldehyde exposure in indoor environments

(Salthammer et al., 2010). The majority of formaldehyde resides in urea-formaldehyde

(UF) and melamine-urea-formaldehyde (MUF) resins in the flooring material (Kim,

2009). This section will identify how indoor environmental conditions (temperature

and ventilation rates) can affect formaldehyde emission levels in buildings to better

understand the Lumber Liquidators case study.

A research team from the Program of Environmental Materials Science at Seoul

National University studied formaldehyde emissions from engineered flooring,

specifically high-pressure melamine and plywood, for both in-floor heating and more

traditional heated air circulation systems. The researchers first measured formaldehyde

emissions from a local commercial engineered flooring company, which uses MUF

resins for adhesion, in a dry oven at 20±1 °C, 26±1 °C, and 32±1 °C for 30 days. The

results showed that higher temperatures yielded higher formaldehyde emission

concentrations (An et al., 2010). Shown in Figure 1, initial emissions were higher for

each temperature test and appear to level off at 1.5 mg/L at 30 days. These results also

confirmed Renata Wiglusz work from the Department of Toxicology at the Institute of

Maritime and Tropical Medicine in Poland and concluded that flooring exposed to

higher temperatures will increase negative effects on indoor air quality through the

acceleration of chemical reactions that produce the emissions (Wiglusz et al., 2002).

Figure 1: Formaldehyde emissions from engineered flooring

The researchers at Seoul National University proceeded to test formaldehyde emission

rates from the adhesive used in flooring, flooring without adhesive, and flooring with

adhesive. This was done to better understand and source formaldehyde emissions in

the flooring materials. Two different methods were used to conduct this test at 25±1 °C.

A 20 L chamber method and field and laboratory emission cell (FLEC) method were

both conducted, with their differences summarized in Table 2. Note the large difference

in ventilation rate between the two methods. Shown in Figures 2 and 3, formaldehyde

emission rates decreased in a similar manner over the 7 days and showed highest

emissions from flooring with adhesive. Despite having the highest emissions rate, it was

concluded that the flooring with adhesive reduced the formaldehyde emissions since

the sum of the adhesive alone and flooring without the adhesive was greater than

emissions of the flooring with adhesive. Emission rate magnitudes between the two

methods are significantly different due to the increased ventilation rate of the FLEC

method (An et al., 2010). This same correlation can be extrapolated to buildings with

higher ventilation rates via a central air circulation systems or decentralized fans. Fresh

air must be exchanged with circulated air to ensure that formaldehyde concentrations

do not reach unsafe levels.

Table 2: Summary of Experimental Methods

Figure 2: Formaldehyde emission rate for the 20 L chamber method

Figure 3: Formaldehyde emission rate for the FLEC method

The final formaldehyde experiment compared emissions behavior between air

circulation and floor heating systems at 20 °C, 26 °C, and 32 °C using the FLEC method.

Shown in Figure 4, higher temperatures in both systems increase the emissions rate,

which is consistent with prior results, however, the floor heating system yields a

significantly higher formaldehyde emission rate than that of just air circulation (An et

al., 2010).

Variables 20 L Chamber FLEC

Chamber Volume

20 L 0.035 L

Ventilation Rate 0.5/h 471.43/h

Temperature 25±1 °C 25±1 °C

Humidity 50±5% 50±5%

Figure 4: Formaldehyde emission rates for air circulation and floor heating systems at varying temperature

The MUF and UF resins used in engineered flooring is used for the plywood adhesion

which is at the base of the flooring board, shown in Figure 5 (Kim and Hyun-Joong

2005). This is very important since in the floor heating system, heat is supplied from the

bottom. In this experiment the temperature of the bottom flooring panel was measured

to be 48 °C, which means the main source of formaldehyde in the plywood was a much

higher temperature than that of the air circulation system, resulting in a greater

emission rates. In conclusion, there is a strong consensus among the research

community for the dependence of both temperature and ventilation on formaldehyde

emissions from wood-based flooring materials, which can negatively affect indoor air

quality.

Figure 5: Engineered flooring schematic

Formaldehyde Source Controls

With relatively current regulations in California and the EPA nearing a national

standard on formaldehyde emissions from wood-based products, manufacturers and

researchers are addressing the need for “low-emitting” formaldehyde building

materials by focusing on UF and UMF resins (Castro-Lacouture et al., 2009). Current

source control strategies will be investigated from manufacturing techniques to the use

of more natural, “green” adhesives with lower emissions.

A study performed by Sumin Kim from the College of Engineering at Soongsil

University in South Korea, found that formaldehyde emissions from floorings can be

controlled during manufacturing steps using surface finishing (Kim, 2010). For this

research, Kim divided the manufacturing of engineered flooring into three steps

(plywood only, fancy veneer bonded on plywood, and UV coated on fancy veneer with

plywood) and measured formaldehyde emissions from each step. The FLEC method was

used to measured emissions for the study. The results showed that formaldehyde

emissions tripled by adding fancy veneer to plywood flooring. Manufactures typically

use UF and UMF resins to bond fancy veneer, which contributes to the increased

formaldehyde. The final step in engineered flooring assembly is a UV-curable coating on

the fancy veneer. When cured properly, the UV coating returned emission levels to that

of the plywood alone. Kim credits this to the UV coating acting as a “covering material”.

This sealing effect of a UV coating for formaldehyde was confirmed in an earlier study

by Kim and other researchers (Kim et al., 2006). Kim’s research illustrates the

importance of manufacturing engineered flooring in efforts to minimize formaldehyde

emissions, specifically the critical final step of applying the UV coating.

In a more recent 2010 study, Kim investigated the reduction of formaldehyde

emissions from engineered flooring through the use of an environmentally friendly

resins derived from cashew nut shell liquid (CNSL). This by-product from cashew nut

processing is a renewable resource and exhibits excellent polymer properties that could

significantly reduce formaldehyde emissions from synthetic resins (e.g., UF and UMF)

(Kim, 2010). CNSL was replaced by urea in UF to create a CNSL-formaldehyde (CF)

resin. Various blends of CF and polyvinyl acetate (PVAc) were also studied to ensure

bonding strengths of the engineered flooring were comparable to that of synthetic

resins. Increasing PVAc composition in the CF resin increased bonding strength without

increasing formaldehyde emissions. The CF and CF/PVAc resins yielded lower

formaldehyde emissions than traditional UF resins. Surprisingly, before the UV coating

was applied to the engineered flooring the CF resin already showed emission levels less

than the E1 grade (below 1.5 mg/L), which is the current Korean Standard. After the UV

coating was applied, both the CF and CF/PVAc resins satisfied the E0 grade (below 0.5

mg/L), which is the grade with the lowest emission level (Kim, 2010).

Kim conducted an almost identical experiment but instead of using CNSL with

formaldehyde, he examined how formaldehyde emissions would change with the

replacement of synthetic adhesives with tannin-formaldehyde adhesives. Tannin is an

excellent alternative from petroleum-derived compounds since it’s concentrated from

the inner layer of tree bark. Just like with CNSL, several tannin/PVAc blends were

created to analyze bonding strengths. Similar trends to CNSL with formaldehyde

emissions were also shown, where all adhesives satisfied the E1 grade prior to UV

coating and E0 after UV coating (Kim, 2009). Kim has shown that there are effective and

more environmentally friendly adhesives, compared to current adhesives, which can

maintain bonding strengths and reduce formaldehyde emissions in engineered flooring.

In cases where formaldehyde-based materials are already place, the possible

solution could be analyzed through the measurement of formaldehyde levels.

Depending on the concentrations and economics of the situation, a replacement of

hazardous materials with low emitting alternatives is one option. Another option could

be to “bake out” the current formaldehyde by isolating the building and using high

ventilation rates with elevated temperatures (32-40 °C) until formaldehyde levels

decrease to safer concentrations (Kim and Hyun‐Joong, 2005).

Conclusion

Although formaldehyde has been a health concern for many years, the recent

investigations into Lumber Liquidators’ flooring products has given rise to public

concerns about the safety of consumer products and formaldehyde in the United States.

In the short term, this will hopefully help initiate the enactment of a national emissions

standard for formaldehyde. The United States government and private industry have a

unique opportunity to collaborate in efforts to improve indoor air quality through the

development of new “low emitting” formaldehyde resins that could replace traditional

ones.

While this would be a great step forward for the United States, there is a need for

the World Health Organization to assist with the formaldehyde pollution problem since

we live in a global marketplace and need safe products whenever they are made. Global

production of formaldehyde was estimated at 35,394 kilotons in 2007 and has been

steadily increasing year-to-year. With nearly 65% of this output going into the synthesis

of resins for construction materials, the world needs universal formaldehyde standards

to ensure the safety of all people (Tang et al., 2009).

References

An, Jae-Yoon, Sumin Kim, Hyun-Joong Kim, and Janghoo Seo. "Emission behavior of formaldehyde and TVOC from engineered flooring in under heating and air circulation systems." Building and Environment 45, no. 8 (2010): 1826-1833.

Aydogan, Ahu, and Lupita D. Montoya. "Formaldehyde removal by common indoor plant species and various growing media." Atmospheric environment 45, no. 16 (2011): 2675-2682.

Castro-Lacouture, Daniel, Jorge A. Sefair, Laura Flórez, and Andrés L. Medaglia. "Optimization model for the selection of materials using a LEED-based green building rating system in Colombia." Building and Environment 44, no. 6 (2009): 1162-1170.

Dannemiller, Karen C., Johnna S. Murphy, Sherry L. Dixon, Kelly G. Pennell, Eric M. Suuberg, David E. Jacobs, and Megan Sandel. "Formaldehyde concentrations in household air of asthma patients determined using colorimetric detector tubes." Indoor air 23, no. 4 (2013): 285-294.

"Formaldehyde Emission Standards for Composite Wood Products." EPA. March 23, 2015. Accessed December 7, 2015. http://www.epa.gov/formaldehyde/formaldehyde-emission-standards-composite-wood-products.

Kim, Sumin. "Control of formaldehyde and TVOC emission from wood-based flooring composites at various manufacturing processes by surface finishing."Journal of Hazardous Materials 176, no. 1 (2010): 14-19.

Kim, Sumin. "Environment-friendly adhesives for surface bonding of wood-based flooring using natural tannin to reduce formaldehyde and TVOC emission." Bioresource Technology 100, no. 2 (2009): 744-748.

Kim, Sumin. "The reduction of formaldehyde and VOCs emission from wood-based flooring by green adhesive using cashew nut shell liquid (CNSL)."Journal of hazardous materials 182, no. 1 (2010): 919-922.

Kim, Sumin, and Hyun‐Joong Kim. "Comparison of formaldehyde emission from building finishing materials at various temperatures in under heating system; ONDOL." Indoor Air 15, no. 5 (2005): 317-325.

Kim, Sumin, and Hyun-Joong Kim. "Effect of addition of polyvinyl acetate to melamine-formaldehyde resin on the adhesion and formaldehyde emission in engineered flooring." International Journal of Adhesion and Adhesives 25, no. 5 (2005): 456-461.

Kim, Sumin, Jin-A. Kim, Hyun-Joong Kim, Hwa Hyoung Lee, and Dong-Won Yoon. "The effects of edge sealing treatment applied to wood-based composites on formaldehyde emission by desiccator test method." Polymer testing 25, no. 7 (2006): 904-911.

Klepeis, Neil E., William C. Nelson, Wayne R. Ott, John P. Robinson, Andy M. Tsang, Paul Switzer, Joseph V. Behar, Stephen C. Hern, and William H. Engelmann. "The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants." Journal of exposure analysis and environmental epidemiology 11, no. 3 (2001): 231-252.

"Lumber Liquidators Class Action Lawsuit Investigation Over Formaldehyde Levels." ClassAction.org. March 5, 2015. Accessed December 7, 2015. http://www.classaction.org/lumber-liquidators.

NTP, “Report on Carcinogens Twelfth Edition. Research Triangle Park, NC: Department of Health and Human Services” Public Health Service, National Toxicology Program (2011).

Ruffing, Thomas C., Paul M. Smith, and Nicole R. Brown. "Resin Suppliers' Perspectives on the “Greening” of the North American Interior Wood Composite Panel Market." Forest Products Journal 60, no. 2 (2010): 119-125.

Rumchev, K. B., J. T. Spickett, M. K. Bulsara, M. R. Phillips, and S. M. Stick. "Domestic exposure to formaldehyde significantly increases the risk of asthma in young children." European Respiratory Journal 20, no. 2 (2002): 403-408.

Salem, Mohamed ZM, Martin Böhm, Jaromír Srba, and Jitka Beránková. "Evaluation of formaldehyde emission from different types of wood-based panels and flooring materials using different standard test methods." Building and Environment 49 (2012): 86-96.

Salthammer, Tunga, Sibel Mentese, and Rainer Marutzky. "Formaldehyde in the indoor environment." Chemical Reviews 110, no. 4 (2010): 2536-2572.

 "Standard Operating Procedure for Finished Good Test Specimen Preparation Prior to Analysis of Formaldehyde Emissions from Composite Wood Products." Http://www.arb.ca.gov/toxics/compwood/outreach/compwood_sop_fg_decon_091313.pdf. September 13, 2013. Accessed December 7, 2015

Tang, Xiaojiang, Yang Bai, Anh Duong, Martyn T. Smith, Laiyu Li, and Luoping Zhang. "Formaldehyde in China: Production, consumption, exposure levels, and health effects." Environment international 35, no. 8 (2009): 1210-1224.

Harvard

Wiglusz, Renata, Elżbieta Sitko, Grażyna Nikel, Irena Jarnuszkiewicz, and Barbara Igielska. "The effect of temperature on the emission of formaldehyde and volatile organic compounds (VOCs) from laminate flooring—case study."Building and environment 37, no. 1 (2002): 41-44.