X03: Exterior Materials and Structures

(Required)

INTENT

Mitigate environmental contamination and associated hazards resulting from treated outdoor structures and wood-plastic materials.

SUMMARY

This WELL feature requires the restriction of wood preservatives and lead, including lead paint, in outdoor structures and provides guidelines for the remediation of lead-contaminated soil and selection of outdoor wood-based plastics.

ISSUE

All types of chemically treated wood release small amounts of preservative components into the environment, which can be detected in soil or sediment samples. Chromium (VI),  applied  in  CCA  and  used  as  a  biocide  in chemically treated wood products and materials, is a known human carcinogen. Evidence links chromium (VI) most strongly to lung cancer, but positive associations have also been seen with cancer of the nose and nasal sinuses. Up to 75% of the lumber produced in the United States from the mid-1970s to 2004 was pressure treated with CCA, which can leach arsenic into the soil, where children, plants and pets can be exposed. The greatest hazard posed by arsenic-containing biocides is potential exposure to arsenic leachate. Inorganic arsenic is highly toxic; studies show that the compound can increase the risk of skin, liver, bladder and lung cancers.

Lead dangers, particularly for children, include wear and tear or flaking of paint found on older playground equipment. This is especially troublesome since children who engage in the ingestion of nonfood items are especially prone to exposure. Maintenance of external metal structures requires lead paint be removed prior to repainting, which further contributes to soil contamination. Other lead-containing materials, such as synthetic turf, can also degrade from use and form dust-containing lead at levels that can pose risk. Exposure to lead is associated with increased blood pressure. Additionally, exposure to lead during early development, even at low levels, is associated with negative impacts on intelligence quotient (IQ), learning, memory, and behavior.

SOLUTIONS

Lead in dust and soil can come from weathering and chipping of lead-based paint from infrastructure (e.g. buildings and bridges) and degradation of other outdoor materials like synthetic turf.  Assessing and remediating lead in outdoor structures and materials, including soil, can help mitigate risk of exposure.

Studies suggest that applying coatings (e.g., oil-based semi-transparent stains) on a regular basis can reduce the migration of wood preservatives from CCA-treated wood and thereby reduce the risk of exposure. Alternatives to wood made from the least harmful plastics [e.g. high-density polyethylene (HDPE) and low-density polyethylene (LDPE)], with higher recycled content and high end-of-life recyclability are ideal and further reduce the use of treated wood and associated risks. 

IMPACT

The restriction of toxic biocides for use on outdoor wood structures mitigates environmental contamination and associated exposure risks. Furthermore, guidelines for the use of wood-plastic materials promotes the use of high- and low- density polyethylene to create an effective closed-loop system of highly recyclable, environmentally preferable plastic products.

REQUIREMENTS

Part 1

Ensure Acceptable Structures

Verified by Architect, Remediation Report, Professional Narrative

For All Spaces

Projects fulfill the following (as applicable):

1. Wood structures manufactured before the institution of any applicable laws banning or restricting CCA are tested. Wood structures containing CCA are replaced or remediated in accordance with the U.S. Environmental Protection Agency's (EPA) Chromated Copper Arsenate (CCA): Consumer Advice Related to CCA-Treated Wood, using penetrating (non-film-forming), oil-based, semi-transparent stains.

2. Artificial turf is assessed and remediated per the following:

   1. Conduct a sample test if lead concentration of synthetic turf fibers is unknown.
   2. If the lead concentration of synthetic turf fibers is greater than 300 mg/kg, perform dust-wipe testing per EPA protocol for dust-wipe testing to determine the surface dust-lead loading.
   3. If the wipe-testing results show lead loadings greater than 40 µg/ft² replace with turf containing lead concentrations less than 300 mg/kg.

Note: Projects can disclose or report ingredients listed here using labels approved for use in Part 1: Promote Ingredient Disclosure in Feature X14: Material Transparency to earn points toward that feature.

A Remediation Report is only required if CCA is found or lead in artificial turf is above the established threshold.

Part 2

Manage Exterior Paint and Soil

Verified by Architect, Remediation Report, Professional Narrative

For All Spaces

Projects fulfill the following (as applicable):

1. Lead hazard assessment (and remediation, if needed) is performed to the top 1.5 cm [0.6 in] of existing bare soil (not covered by grass, vegetation or other landscaping including mulch covered soil) outside the building envelope and within the project boundary, following the guidance provided by US Federal Code 40 CFR Part 745; Subpart L; §745.227, "Work practice standards for conducting lead-based paint activities: target housing and child-occupied facilities." Relevant sections are listed below:
   

   1. Risk assessment (d)(8-11).
   2. Abatement (e)(7).
   3. Determinations (h)(4).

2. Industrial surface paints and coatings contain less than 0.1% by weight lead in the form of lead or lead compounds.

Student or childcare areas:

Projects fulfill the following:

1. Paint on playground equipment is assessed and, if necessary, remediated in accordance with guidelines set by the Consumer Product Safety Commission Staff Recommendations for Identifying and Controlling Lead Paint on Public Playground Equipment.

 

 

Note: Projects can disclose or report ingredients listed here using labels approved for use in Part 1: Promote Ingredient Disclosure in Feature X14: Material Transparency to earn points toward that feature.

A Remediation Report is only required if lead is found above the thresholds established in the referenced guidelines.

© International WELL Building Institute