10
Overview of Building Material Components
In todayās world of plastics and advanced technology, assessing building material emissions and combustion products is like attempting to control a menagerie of monkeys. Once you think you have a handle on it, you encounter the unexpected. The task is difficult but not impossible. So, letās get started.
Function versus Type
Building materials are typically identified by type, not by function. Type is a general description of products that serve multiple functions. It does not address trade differences in terms of product composition (e.g., mineral wool insulation versus mineral wool ceiling tiles). It does not encompass degradation challenges (e.g., insulation in wall cavities versus insulation in air conditioning units). It does not discern the differences between interior and exterior products (e.g., exterior wood siding versus interior bead board). So, letās look at a few of these differences.
ā¢The framing and carpenter trades use lumber and composite wood products. Sounds simple enough! The type is lumber and composite wood. But not so fast! Framing is accomplished with treated/untreated lumber and composite āstructuralā wood and sheathing. Wood cabinets are comprised of āfine lumberā and veneered composite wood products. Framing materials are enclosed, and cabinets are interior. The type of building material is the same. Yet, the composition and accessibility is different.
ā¢The plumbing and window installation trades use vinyl building materials. All vinyl additives are not the same; exposure environments are not the same; and degradation is not the same. The most common material used in plumbing is polyvinyl chloride pipe which is generally enclosed, not exposed to solar heat and UV light. On the other hand, window frames comprised of vinyl are often interior/exterior and exposed to solar heat and UV light. Additives used in PVC pipe and vinyl windows are also different. While the type of building material is the same, the composition is different. Environmental conditions are different, and solar conditions differ.
ā¢The insulation and HVAC trades use insulation. Insulation contractors install fiberglass insulation, and HVAC contractors install fiberglass duct board. Loose-fill fiberglass insulation is installed in wall cavities/attics. It is generally enclosed, not subject to air disturbances. Rigid fiberglass duct board is, however, subjected to considerable air movementāair that is delivered to the occupied spaces on the interior of a building. Once again, materials are different, and conditions are different.
Thus, a discussion of ābuilding materials by functionā allows for extended conversations regarding composition, location, environmental influences, and special conditions.
Composition Gone Wild
The ātoxic stew of chemicalsā in building materials is on the rise. As of January 2016, more than 106 million unique organic and inorganic chemical substances and more than 66 million sequences were CAS-registered worldwide. About 15,000 chemicals are added on a daily basis (CAS 2016). Toxicological information is severely lacking!
As the world of chemistry races out of control and technology reaches for the stars, health hazards associated with building materials are becoming more and more elusive. Products are comprised of the reputed, long standing toxins of the past, poorly understood polymers of today, and those in between.
Toxins of Old
Asbestos, lead, and sand/quartz (e.g., crystalline silica) are long standing toxic building materials that, in some respects, allowed advances in construction and in civilizationsānot unlike that of todayās polymers. Some of the advances were sand and limestone bricks dating back to ancient times, the Roman lead potable water supply systems, asbestos fireproof roofing. Yet, today, they are the scourge of construction. Builders must manage building materials with caution, comply with federal, state, and local regulations, and remediate asbestos-containing and lead-based paint containing building materials. Airborne dust and water exposure health hazards, asbestos and lead are environmental and occupational health hazards whereas crystalline silica is an occupational hazard. Not one emits gases. So, you query, Why even mention these health hazards?
Unbeknownst to most builders, asbestos and lead is still manufactured and sold for use in building materials to this day. Such asbestos and/or lead-containing building materials may or may not be legal. They may or may not be reported. As for sand/quartz, OSHA regulated crystalline silica is in more building materials than builders are generally aware. For this reason, building materials containing asbestos, lead, and/or sand/quartz are identified and briefly discussed herein.
Polymers Run Amuck
As compared to the toxins of old, todayās synthetic polymers are plastics run amuck. Used extensively in the later part of the twentieth century, there have been limited toxicological studies performed. Thus, polymer off-gassing and associated health hazards are not easily predictable. New polymers, plasticizers, and additives are being introduced daily. It is difficult, if not impossible, to track new polymer formulations and new polymer-containing building products.
There is a modicum of understanding regarding thermoset polymers, most of which are formaldehyde-based resins such as urea formaldehyde and phenol formaldehyde. With their increased use, formaldehyde emissions have a low odor threshold and may cause eye, skin, and respiratory tract irritation at low levels. Formaldehyde is regulated. Many of the formaldehyde emission sources are generally composite wood products such as plyw...
