Part III: Formaldehyde Exposure Modeling Science Series

This posting is the final installment of a three-part series on formaldehyde emissions from hardwood plywood (HWPW), medium-density fiberboard (MDF), and particleboard (PB), collectively called composite wood products. This series focuses on the benefits of applying computer modeling tools to the interpretation of formaldehyde emission data, and subsequent risk management decisions.

Part 3: Five Reasons Why Computer Modeling is an Essential Tool for Manufacturers, Importers, and Distributors of Composite Wood Products

This posting is last of a three-part series on formaldehyde emissions from hardwood plywood (HWPW), medium-density fiberboard (MDF), and particleboard (PB), collectively called composite wood products. Starting in the summer of 2017, manufacturers, distributors, and importers of composite wood products will be subject to the new Emission Standards for Composite Wood Products posted as a pre-publication final rule on July 27, 2016, as Title VI of the Toxic Substance and Control Act (TSCA). The emission standards will mandate that wood products within the scope of the rule comply with emission test requirements conducted under prescribed conditions. The emission standard is consistent with and modeled after a similar existing regulation previously promulgated by the California Air Resources Board (CARB) as an Airborne Toxic Control Measure (ATCM).

There are five important reasons why companies in the composite wood product supply chain should consider exposure modeling as part of their regulatory compliance and due diligence strategy. 

#1: Understand the contribution of emissions from your product to overall air quality

Computational models can help manufacturers, distributors and retailers assess the specific contribution of their product to indoor air quality in the environment for which the product is intended, which is likely less than what would be predicted by the controlled emissions tests that will be required by U.S. EPA. Under real-world conditions, formaldehyde emissions from consumer products are affected by aging of the material, interactions between materials, and attenuation of airborne concentration through the loss of formaldehyde to adsorptive surfaces. Exposure models are an invaluable tool that can be used to understand how the introduction of a new product into a residence or workplace will affect air quality.

#2: Evaluate the effect of environmental factors on your product   

Environmental factors such as temperature, humidity, and fresh air turnover can alter how emissions from composite wood products affect indoor air quality. Exposure modeling can be very useful for understanding how a specific product may respond to changes in the environment.  For example, modeling can be used to predict the impact of a range of plausible and worst-case scenario conditions. This knowledge can be very useful for responding to customer complaints, or in the preparation of product quality assessments.

#3: Assess emissions over the lifetime of a product

The controlled emissions tests used to comply with voluntary or regulatory standards do not consider the decrease in formaldehyde emissions that occur as the product ages with time. Exposure models provide useful information on the contribution of a product to indoor air formaldehyde concentrations over the lifetime of the product, not just when it is newly installed. This information can be very useful for understanding the length of time a product is likely to affect indoor air concentrations, or in the assessment of lifetime exposure.

#4: Interpret air concentration measurements that may have been collected by others    

Indoor air measurements can be commissioned by building owners or consumers to support a complaint or product defect claim. Alternatively, products may be removed by the owner and submitted for analysis in a laboratory. Room measurements or product samples collected by building owners are difficult to interpret because formaldehyde is used as a resin or preservative in a wide variety of consumer products, occurs naturally in wood, and is a component of ambient outdoor air. A single air sample collected in a room captures all sources formaldehyde and is not specific to a product of concern.

It is noteworthy that low emitting formaldehyde sources can capture formaldehyde from other sources, and subsequently reemit formaldehyde that was not present in the original product.  Both indoor air measurements and tests of used products are impacted by these other sources. Exposure modeling can be a useful tool for understanding how a specific product may have contributed to a measured indoor air concentration. Similarly, modeling can be used to understand whether a sample of a used product may have been impacted by environmental formaldehyde.

#5: Develop an action plan to address non-compliant products

The existing CARB and newly finalized U.S. EPA emissions standards have many steps in place to prevent non-compliant products from entering the chain of commerce. The possibility exists, however, that a non-compliant product will be sold to consumers and subject to a customer complaint or regulatory compliance action. In these cases, exposure modeling is a very valuable tool for assessing whether a non-compliant product will have a meaningful impact on air quality. Additionally, a model can be used to evaluate the duration of time the product would remain non-compliant before aging processes sufficiently reduce the airborne concentration. These factors may impact risk mitigation plans in the event a product is determined to be non-compliant in one of the various stages of the supply chain.  

How Cardno ChemRisk Can Assist with Questions about Formaldehyde

As a state-of-the-art scientific consulting firm, Cardno ChemRisk is well respected for its leadership in human health risk assessment – including computational modeling and statistical services. Cardno ChemRisk has extensive experience using computational modeling to understand past and future exposures in both occupational and environmental settings, especially in situations where collecting measurements is either impossible or impractical. In addition, Cardno ChemRisk applies a variety of statistical methods to understand the important relationships hidden within an environmental or occupational data set. If you are interested in discussing our recommendations for consumer product formaldehyde exposure modeling in more detail, please contact  Ken Unice, the Science Advisor and Computational Science Service Area Lead at Cardno ChemRisk.