Which of the following is NOT one of the six substrates recommended by HUD?

The recommended substrates by HUD (the U.S. Department of Housing and Urban Development) for lead-based paint risk assessments are designed to encompass a variety of materials that may be found in residential environments. These six substrates include materials that are commonly used in housing and can have lead-based paint when the home was built before 1978, the year when the U.S. banned the use of lead in residential paint.

Glass, while it can be surface-coated with paint or lead-based materials, is not typically classified as a substrate in the same way that concrete, metal, and drywall are. Concrete, metal, and drywall are structural or functional materials commonly found in homes and are often painted, making them relevant to lead assessments.

Choosing glass as a non-substrate reflects its limited association with lead-based paint in the context of HUD’s recommended practices, as it is generally not considered a principal surface for lead risks. This distinction emphasizes the types of materials that are more effectively checked and assessed for lead hazards within the home.