Mulch & Soil Council Acts to Protect the Public: CCA-Treated Wood is Prohibited in Mulch

News Release

For Immediate Release August, 2004

Mulch & Soil Council Acts to Protect the Public:
CCA-Treated Wood is Prohibited in Mulch

In 2001, a relatively obscure study of Florida landfills caught the attention of the Mulch & Soil Council (MSC) by accident. Researchers at the University of Florida and Miami University investigated the Florida waste industry's disposal practices for CCA-treated wood. The initial concern was that the arsenic in CCA-treated wood could contaminate groundwater when disposed in unlined landfills. As a result of that study, a series of events occurred that have rocked the Lawn & Garden Industry. This paper recounts how those events unfolded and how the MSC reacted responded to them to protect protecthonest mulch manufacturers and the public.

Landfill practices are not normally a concern of the Mulch & Soil Council. However, an ancillary claim of the Florida research stated that some CCA-treated wood was being ground, colorized and sold as mulch for consumer garden use. The study was limited and the mulch issue was a minor finding from a very small sample, but it caused great concern among the members of the Mulch & Soil Council. Subsequently, various news articles around the U.S. have stated that arsenic in mulch is a problem. Some of these articles have stated incorrectly and over-simplistically that “colored” mulches are the problem, while others have gone further and blatantly stated such mulch causes cancer. In addition to technical issues related to wood recycling, public misinformation now has complicated the problems.

The issue is complex because it involves many people from various disciplines, like industry, academia, and government, each interpreting the problems differently as they apply to multiple fates and uses of CCA-treated wood. For example, one set of regulations covers the use of the product itself (i.e. as a construction material) and the safety aspects for its intended use. Then, there are general environmental regulations for the protection of water and soil from any material (i.e. drinking water standards and soil clean-up standards). Further, there are multiple sets of regulations that apply to disposal of solid wastes in the U.S. Due to the nature of any given material, classifying which disposal regulations apply is often complex and contentious. This dilemma was the primary subject of the Florida study. Finally, there are general, broad-brush regulations that pertain to the safety of any consumer product sold in the U.S. So, determining how CCA-treated wood intertwines with all these regulations, uses and end-use fates involved interpretations from many people and agencies. And determining the safety of a material in each of these circumstances involves very different test methods and data analysis. All of this is the complex part. But as will be pointed out later, the MSC has chosen a very simple but powerful solution to the issue of CCA-treated wood as it pertains to mulch. However, the chronology of events will first be described as a backdrop to the MSC's solution for mulch.

In the Florida research study, it was concluded that CCA-treated wood was a major potential source of high levels of arsenic that could contaminate groundwater. Current waste management regulations in Florida allow CCA-treated wood to be discarded in Construction and Demolition (C&D) wood landfills, which are unlined. To protect Florida's groundwater supply, the researchers recommended that CCA-treated wood be disposed in lined sanitary landfills in order to prevent arsenic leaching into groundwater. That conclusion was strongly contested by the wood preservative industry and seemingly unsupported by EPA regulations on CCA wood disposal rules.

Chromated Copper Arsenate (CCA) is a regulated pesticide that is high in arsenic and applied to wood under pressure to control insect and fungal deterioration for wood decks, fences, docks, garden timbers, playground equipment and other industrial and consumer products. Its use began in the 1980s as a popular outdoor building material. Billions of board feet have been used until January 2004. At that time, the U.S. EPA and the wood preservative industry agreed to discontinue production of CCA-treated wood, but only for consumer uses.

In October 2001, the Council held its annual industry meeting and invited the University of Florida researcher to review his study and inform the industry on issues relating to CCA wood for the first time. That first look at the study caused the MSC board of directors to inquire further.

At the same time, the Council had just launched a national product certification program for garden potting soils and mulch. Certification is a manufacturer's opportunity to demonstrate his product's compliance with industry standards and product labeling. It had been a developing program of the Council for four years in an effort to protect consumers from unacceptable products and fraudulent label claims. With the University of Florida research suggesting there may be an issue with CCA contamination of mulch, the Council immediately suspended certification of all mulch products containing any recycled wood until further study would indicate the proper treatment of CCA materials.

Throughout 2002, the Council investigated the Florida study, CCA wood issues and any guidelines that might help the industry expand its standards to address this previously unknown issue. The MSC did not find any standards, tests, regulations or data that would help answer the growing number of questions pertaining directly to CCA wood use in mulch. After months of debate over the proper procedures, the Council chose to explore the applicability to mulch of using an existing regulation for land application of sewage sludge (40 CFR, part 503). This regulation contains land application limits for heavy metals including arsenic. In October 2003, a delegation of MSC representatives was dispatched to the EPA in Washington, D.C., to validate the industry's choice. EPA responded that the 503 regulations were not applicable for a surface treatment like mulch and confirmed that no standards or test procedures existed to address the Council's questions regarding CCA.

The Council's Standards Committee went back to the drawing board. The Committee considered leachate tests to determine levels of arsenic and other elements, similar to what the Florida researchers used. However, this approach was determined to be inappropriate since these are disposal/landfill tests that simulate the material buried in acidic landfill conditions. This is not even closely representative of a surface application of mulch that would contain limited amounts of CCA-treated wood.

The drinking water standards were also determined to be inappropriate since this would require testing the leachability of the elements in soil profiles with real-life mulch applications. No such tests existed and would require years of study to develop. The state soil cleanup standards were also inappropriate since they rely on a complex organic soil matrix to filter heavy metals like arsenic. Obviously, the MSC desired a relatively quick test to determine if a mulch was a risk to the environment. None of the options seemed to provide this or even offer a test method with reasonable applicability.

At this point it is proper to note that EPA had long exempted CCA-treated wood from consideration as a hazardous waste for landfill disposal purposes. Two months after the MSC visit to EPA, the Agency issued a special memorandum expressing concern for the environmental aspects of CCA-treated wood in mulch. The memo stated that indeed CCA wood was not a hazardous material when used in its intended form (i.e. as a building material). However, the memo went on to say that mulching or grinding was not covered under the CCA exemption as a hazardous waste, and CCA should not be used for mulch unless it can pass the non-hazardous waste test. The EPA clarification memo was issued in January 2004. Although this memo imposes some restrictions on CCA-treated wood in mulch (e.g. it must pass the hazardous waste test), the MSC believes it does not go far enough.

By 2003, the Council had acquired enough information to develop and issue an industry position paper strongly recommending against the use of CCA treated wood in mulch. As the scientists and researchers argued over what to do, or not do, the Council took a pro-active, clear, and simple position.

Since the wood preservers mark every piece of CCA-treated wood with a tag that says "Do not grind or mulch", it seemed practical to do as the manufacturers state and not support any efforts to grind or mulch any amount of CCA-treated wood.

Two points support this position. Specifically, when a manufacturer explicitly instructs a user not to do something, we believe it is common sense to follow that warning. The second reason is that Chromated Copper Arsenate (CCA) is a registered pesticide for the treatment of construction wood. As such, it is regulated under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). A cornerstone provision of this act states that it is a violation of federal law to use a pesticide in a manner inconsistent with its labeling.

Since CCA is not registered for the treatment of mulch and the manufacturer explicitly states on its label not to grind or mulch, to do so is both an unregistered use of a pesticidal product and a violation of its labeling, both of which are unlawful acts. Thus, the MSC believes that the use of CCA-treated wood in mulch is not only a breach of common sense and the manufacturer’s recommendations, it is a violation of federal law.

This rationale makes the issue broader than any specific elements of concern, such as arsenic or chromium. Instead, it is an issue of using CCA-treated wood that can result in environmental contamination from its component elements. In choosing this approach, the MSC did not have to determine what is a safe level of arsenic or other elements in mulch. Such determinations generally take years of risk-assessments, can only be done by Federal and State authorities, and in the end, are still contentious. So the MSC position developed by the Standards Committee was that no CCA-treated wood should be allowed in mulch, period. However, the MSC still had to officially adopt this position into its standards and then to develop a detection test for CCA-treated wood in mulch, since certified mulches would need to be tested for conformance.

In February 2004, the Standards Committee recommended to the MSC Board of Directors that no CCA-treated wood be allowed in mulch. This position was accepted by the board and sent to the general membership for review and approval by majority vote. In addition, as is customary for trade association activity, the proposal was sent out to the trade media and nonmembers for comments. During this time, the Standards Committee had been testing a procedure for the detection of CCA-treated wood in mulch.

Several testing proposals were reviewed with assistance from industry laboratory experts and advisors from North Carolina State University. Because mulch is such a mix of non-uniform particles, it is difficult to test and the procedure must assure that even a low level of mixing CCA wood with natural wood could not elude detection. The final test protocol requires the entire contents of a bag to be ground into 1/16-inch particles (virtual sawdust) that is thoroughly mixed and then sampled for uniformity. Samples of many different mulch materials, including virgin and recycled wood, were tested along with special samples containing known quantities of blended CCA wood (spiked samples). The results indicated the test was sensitive to levels as low as 0.5% CCA content.

On June 14, 2004, the MSC membership unanimously adopted the proposed standards prohibiting CCA-treated wood in mulch. On July 9, 2004, the MSC Board of Directors ratified the membership vote on the revised standards, adopted the testing protocol for the detection of CCA-treated wood in mulch and lifted the certification moratorium on mulch products. The Council has begun certifying mulch using the newly adopted testing procedure for both initial certification and random audit testing of market samples during the year.

While various groups debate the issues of CCA-treated wood in landfill situations, use in construction, etc., the MSC has acted in a responsible and sensible way to protect the public from CCA-treated wood in mulch. It is virtually impossible for consumers and even trained experts to tell if CCA-treated wood is in any particular mulch just by looking at it. However, the MSC can now make that determination with its testing protocol.

Mulches certified through the Council give consumers, product buyers, regulators, and the general public some level of assurance that they have passed the requirements of mulch certification, which now include a CCA-detection test. While it is not possible to inspect every bag of mulch produced, random testing and public exposure of violators has been a significant deterrent in similar matters, and it is the only form of inspection available from any public or private agency today. MSC certified products can be identified by the presence of the MSC Certification Seal that may appear on the product bag and/or by referring to the product listings on the Council's web site at www.mulchandsoilcouncil.org.