This information reflects our best understanding of product composition in 2020.
Drywall is composed of gypsum plaster pressed between a paper lining. The key material is gypsum (calcium sulfate), which is available in different hydration levels, and in anhydrous form. Natural gypsum stone is calcium sulfate-dihydrate (CaSO4*...
Drywall is composed of gypsum plaster pressed between a paper lining. The key material is gypsum (calcium sulfate), which is available in different hydration levels, and in anhydrous form. Natural gypsum stone is calcium sulfate-dihydrate (CaSO4*2H2O). The anhydrous calcium sulfate can be found in nature as anhydrite (CaSO4). Gypsum also occurs in large quantities as the industry by-product, otherwise known as flue-gas desulphurized (FGD) gypsum. There are not significant differences in the composition of finished drywall products made using these different source materials, but natural gypsum is preferred over FGD gypsum because the FGD drywall production process can release mercury into the environment. The amount of FGD and natural gypsum used in drywall varies regionally. Products tend to be composed primarily of one type or the other. Boards can also contain around 1-10% recycled scraps from the drywall manufacturing process and drywall installation or demolition. This common product profile characterizes a type X drywall product made with FGD gypsum. Type X drywall is fire rated drywall that is more fire resistant than standard drywall. It is specified in many building codes for use in a variety of commercial and residential applications. Examples include interior and exterior walls near furnaces and utility rooms, and in the walls and ceilings of attached garages adjacent to the main living area. It has greater thickness and special core additives (mainly vermiculite and fiberglass) which provide additional fire resistance, higher rigidity, and enhanced sound attenuation as compared to regular 1/2” gypsum board. 5/8” (16mm) type X North American gypsum boards are manufactured to ASTM C1396, Standard Specification for Gypsum Board.
This is not necessarily representative of all possible content that may be found in this product type. It includes all of the potential content identified during the research process for this Common Product profile. All Content data goes beyond the most common chemicals and materials to provide a more comprehensive representation of what may be found in specific product types. It does not necessarily include all chemicals and materials that may be used by all manufacturers and should not be used as a replacement for a specific manufacturer's product disclosure.
About Process Chemistry
Pharos process chemistry does not necessarily represent all chemicals that may be
used in the production of a chemical or material and may list chemicals that are not
used in all manufacturers' processes. We recommend using Pharos process chemistry as a
starting point in conversations with product manufacturers and chemical suppliers to
determine process chemicals that are relevant to specific products, including known
and potential impurities and residuals. For more information see the
Pharos system description.
Sources
Sources
Transformation Target
GreenScreen Score
What are Common Products?
A Common Product profile (CP) is a list of substances that are most commonly present in a product type (vinyl composition tile, for example) as delivered to building sites in North America. The profiles are not specific to any manufacturer.
CPs are organized by chemical function. Every substance in a product performs some function - for example, it thickens a paint, or gives a carpet resistance to stains. The CPs provide the most common substance serving each function in a given product type, the hazards these substances carry into a building project, and a general description of the product type. CPs are based upon a wide range of publicly available information, including product declarations, patents, and chemical suppliers' brochures that detail the functional uses of various additives.
For those wanting more than the most common chemical for each function, Pharos subscriptions provide access to the full catalog of possible ingredients that we’ve found may be in products. Where available, these are displayed in the All Contents tab.
The GreenScreen® for Safer Chemicals™ is a benchmarking system to rank the safety of chemicals on a 4 point hazard scale and encourage progress toward safer alternatives. Chemicals that have undergone a full GreenScreen® Assessment™ by Licensed GreenScreen Profilers are given a GreenScreen Benchmark™ score, which is the most authoritative. Chemicals that have been screened using an automated comparison to hazard lists are given a GreenScreen List Translator™ score, which is less authoritative. Full GreenScreen Assessments trump results from List Translator scoring.
GreenScreen scores in order from highest concern to lowest concern are: