I totally agree with you. This concern is often overlooked by green-minded homeowners and contractors. There are indeed toxic chemicals in conventional, ready-to-use, premixed joint compounds.
- Some contain formaldehyde and aldehyde.
- And all conventional premixed joint compounds contain biocides, the chemical preservatives that increase shelf life and prevent the wet, ready-made products from growing bacteria and mold.
Most of the chemicals like formaldehyde will eventually dissipate, but biocides never go away. Biocides remain for the life of the product, because they have a higher boiling point, while chemicals like formaldehyde and acetaldehyde will eventually dissipate, because they have a lower boiling point.
After formaldehyde, acetaldehyde, and other chemicals dissipate, which takes a varying amount of time, some people, unless chemically sensitive, do not detect chemical odors. Time to dissipate can vary greatly, however, depending on humidity, temperature, ventilation and fresh air exchange. Most people who are not highly chemically sensitive do not detect biocides, even though they are present and never go away, because biocides do not emit odors.
You mention synthetic binders, like PVA (polyvinyl acetate) or acrylic polymers (resins).
- These are usually the least problematic ingredients in conventional joint compound.
- In fact, some great nontoxic glues and paints contain those very same ingredients, and are not considered to be toxic even by many chemically sensitive people.
- Other conventional joint compounds contain synthetic latex additives, such as polyvinyl acetate latex, and ethylene vinyl acetate latex. Many chemically sensitive people cannot tolerate latex additives in building products.
On the MSDS (material safety data sheet that manufacturers must provide for all their products), you'll find the chemicals above listed under hazardous ingredients, but you won't find biocides listed. This is because the amounts added are below the weight or volume that is required to be listed by the manufacturer. In other words, the manufacturer is not required to disclose whether or not a joint compound product contains biocides.
Although there are now conventional "green" drywall compounds on the market that are either low-formaldehyde, or formaldehyde- and aldehyde-free, all conventional joint compounds must contain chemical biocides if they are premixed.
Personally, even though I don't physically react to biocides as do many of my sensitive clients, I still prefer biocide-free, chemical-free building and interior materials whenever possible, rather than products that contain, for example, chemical fungicides and mildewcides.
But here are some factors that may help you decide which is best in your case: alternative, nontoxic joint compounds or conventional ready-mix drywall joint compound:
The alternatives
If you, like me, always prefer the healthiest building materials available, you can instead use an alternative joint compound. These are three alternatives that I specify for my chemically sensitive clients, and those preferring the least toxic products available. All are chemical-free and biocide-free. Keep in mind that you probably won't be able to pick these up at your local hardware or building supply store, so you most likely will incur hefty shipping costs.
o KEIM Dolomitspachtel, the only ready-to-use, premixed, chemical-free, biocide-free joint compound. The natural lime in this joint compound preserves the product without chemical biocides. This product is more expensive than conventional ready-mix joint compounds.
o Murco M-100, a dry, chemical-free joint compound. Murco is a very popular alternative, successfully used by many contractors, but requires more labor time. Some contractors don't feel that it provides a hard enough surface, however, or feel that it may crack more easily in earthquake-prone areas.
o Hamilton Smooth Set and Smooth Set Light Weight, also called Westpac Fast Setand Fast Set Lite. To avoid biocides, purchase Hamilton Smooth Set or Smooth Set Light Weight, Westpac Fast Set and Fast Set Lite in bags only (not boxes), and do not purchase Eco-Finish or any other versions offered by Hamilton and Westpac.
Smooth Set and Fast Set are actually patching compounds, but as long as a contractor is skilled with applying fast-drying plasters, this is a great, healthy alternative product that dries very hard. However, it does require more labor and definitely more application skills.
What if your project does not allow for increased budget and/or time?
You may be concerned that your contractor does not have the required skills or patience to successfully mix and apply a dry product. Or your project's timeline and/or budget may not allow for the nontoxic alternatives. In that case, minimize the use of conventional, premixed joint compound.
- Simply limit the application to the joints only.
- Forgo using the joint compound as a skim coat, to create a texture on the wall under the paint.
(Note: If you are chemically sensitive, a conventional product, however limited in application, may not be appropriate for you.)