What are the ingredients in joint compound?
The compound is a complex combination often including water, limestone, expanded perlite, ethylene-vinyl acetate polymer, attapulgite, and other ingredients. The delicate mixture of compounds gives it a creamy texture that spreads easily onto drywall surfaces and then hardens as the moisture evaporates.
Does drywall create silica dust?
Drywall is made of gypsum (calcium sulfate dihydrate), paper, and additives such as mica, clay, and resin. Drywall installation generates gypsum and silica dust, which are irritating to the lungs. Workers should wear personal protective equipment such as safety glasses, gloves, and dust masks when handling drywall.
How much silica is in drywall dust?
Whether part of the composition or as an impurity, a look at a safety data sheet for drywall, joint compound, and cement board indicates up to 0.56% (in gypsum), <1.0%, and <0.7% crystalline silica by weight, respectively, for these building products.
Does USG joint compound have silica?
Raw materials in USG's All Purpose Joint Compound, Ready-Mixed contain respirable crystalline silica as an impurity. The weight percent of respirable crystalline silica found in this product is < 0.7%.
Is joint compound safe to breathe?
A study by the National Institute for Occupational Safety and Health (NIOSH) has shown that "nuisance dust" from joint-compound mud used in drywall work can contain toxic materials. And, there can be dangerously high amounts of dust from sanding and other drywall work.
Is joint compound toxic?
Drywall joint compound can contain harmful ingredients, including formaldehyde and acetaldehyde, both known carcinogens, and crystalline silica, which is a carcinogen when inhaled.
Does mortar have silica?
Crystalline silica is a common mineral found in the earth's crust. Materials like sand, stone, concrete, and mortar contain crystalline silica. It is also used to make products such as glass, pottery, ceramics, bricks, and artificial stone.
Does all drywall contain silica?
Silica, a dangerous substance, has historically been found in drywall. Yet, in recent years suppliers have offered silica free compounds. The drywall you purchase from your supplier likely does not contain silica. We do caution you to check your supplies to ensure you are using a silica-free compound.
Should you wear a mask when sanding drywall?
Personal Protection N95 face masks should be worn by workers whenever they are sanding drywall. Protective eyewear is also crucial.
Is Green drywall toxic?
Greenboard is not toxic. It's installed in homes, offices, and storefronts across the country. Greenboard is only harmful when exposed to fire and releasing chemicals. Drywall is much more toxic; it makes up 15% of construction and demolition waste.
What brand of drywall is best?
What are the Best Drywall Brands?The National Gypsum Company: This company makes natural gypsum boards that are entirely VOC-free when paper-backed. ... USG Corporation (maker of the well-known brand Sheetrock): Sheetrock's SDS sheets claim to have absolutely no VOCs.More items...•
Can drywall dust cause skin irritation?
Another danger posed by drywall dust is its potential to cause skin irritation. The dust can contain harmful chemicals that can cause skin allergies, redness, itchiness, rashes, etc. As such, construction workers should always wear gloves and other protective clothing when working with drywall dust.
How harmful is drywall dust?
To answer your question in short: drywall dust is not toxic to the body in smaller amounts. This means it will not cause any long-term diseases. However, it can irritate parts of the body, like the eyes and throat. This is because it is made of a chemical known as gypsum (calcium sulfate dihydrate).
Does drywall cause silicosis?
Silica can cause a dangerous condition called silicosis and other health conditions. Calcite contains calcium carbonate, another substance associated with silicosis. Short-term exposure to drywall dust irritates the eyes, skin, and respiratory system.
How long does drywall dust stay in the air?
Particles less than 10µm in diameter (thoracic) will take about 3 minutes to settle. Particles at 5µm in diameter (respirable) will settle in about 8 minutes. Particles with a diameter of 1µm (respirable) will take up to 4 or more hours to settle.
Where is silica dust found?
Silica dust (crystalline silica) is found in some stone, rock, sand, gravel and clay. The most common form is quartz. Silica dust can also be found in the following products: bricks.
What percentage of silica is in drywall joint compound?
Question 9: Drywall and drywall joint compound frequently contain only trace amounts of silica (frequently less than 1 percent ). Is work on or with such materials covered by the standard?
What is the RCS standard for construction?
Response: OSHA’s RCS construction standard applies to all employee exposures to respirable crystalline silica in construction work, except where the exposures will remain below the action level (AL) of 25 micrograms per cubic meter (µg/m 3) as an 8-hour time-weighted average (TWA) under any foreseeable conditions (see 29 CFR 1926.1153 (a)). OSHA has identified the following tasks that are likely to be outside the scope of the RCS construction standard because they typically generate exposures below the AL of 25 µg/m 3 as an 8-hour TWA under all foreseeable conditions when they are performed in isolation from other silica-generating tasks: mixing small amounts of mortar; mixing small amounts of concrete; mixing bagged drywall compound that contains crystalline silica only as a trace contaminant; mixing bagged exterior insulation finishing system base and finish coat; removing concrete formwork; using block or tile splitters; and using manual (i.e., non-powered) chisels, shears, and utility knives. In addition, tasks where employees are working with silica-containing products that are, and are intended to be, handled while wet, are likely to generate exposures below the AL under any foreseeable conditions. Examples of such tasks include finishing and hand wiping block walls to remove excess wet mortar, pouring concrete, and grouting floor and wall tiles.
Can you mix mortar above RCS?
Employers should be aware that tasks like mixing mortar or concrete can foreseeably result in exposures at or above the RCS AL, depending on factors such as the duration the task is performed, location, and the method used for mixing.
What is the main ingredient in joint compound?
Because of that nature, limestone becomes the main ingredient of joint compound. Vinyl Acetate Polymer. Another chemical often used as chemical in joint compound is vinyl acetate polymer. Belongs to the polymer family, it is often used as adhesive in wood glue and white glue as well as book binding.
What is joint compound?
Joint compound is a base to connect the joints between sheets of a drywall. The purpose of joint compound use is for a seamless looking wall. With the joint compound, a light dry wood material for the wall will look smooth as the joint is covered by this material.
What is the chemical name for a joint compound?
Joint compound often contains magnesium aluminium phyllosilicate. It is known more as Palygorskite or Attapulgite. The chemical is white to grayish with transluscent diaphaneity. Attapulgite is widely used in smoothen out the work. This component in joint compound acts as deposit clay to make the drywall dough solid and fulfilling.
How many chemicals are in joint compound?
However, some of the chemicals that created it are questionable. They may be hazardous, thus, make sure to always read the label before using it. Indeed, there are 7 chemicals in joint compound that are commonly or were used. Check Usual Signs of Overexposure to Hazardous Chemicals Include for more information.
What are chemicals used for?
The chemicals are utilized to enhance the function of those materials as . It is either as adhesive, emulsion, or preservative. Those can be the naturally occurring or synthetic one as mentioned in the branches of chemistry. Chemicals in property are also utilized in the making of joint compound.
What is limestone made of?
Limestone is a sedimentary rock formed from calcium carbonate. It is the crystal form of the chemical formula CaCO 3. The sedimentary rock is composed of grains. The washed grains accumulate and eventually undergo sedimentation and form limestone. When grains do not exist, limestone can also be formed from precipitation of aragonite and calcite. A similar one to magnesium carbonate (Read: Chemical Formula and Uses of Magnesium Carbonate ).
Is vinyl acetate soluble?
Vinyl Acetate is soluble and acts as emulsion in gluing things together. The chemical can get fungi or algae infestation as it is does not have solid form. Vinyl acetate is one of the chemicals used as wood adhesive in joint compound. Magnesium Aluminium Phyllosilicate.
What is joint compound?
Joint compound (also known as drywall compound or Mastic) is a white powder of primarily gypsum dust mixed with water to form a mud the consistency of cake frosting, which is used with paper or fiber joint tape to seal joints between sheets of drywall to create a seamless base for paint on interior walls.
How many types of joint compounds are there?
There are mainly three types of premixed joint compounds.
How to use setting type joint compound?
Setting type joint compounds come in powder form and are mixed with water immediately before use. This type contains plaster of paris and sets through a chemical hardening process rather than evaporation, which gives it an advantage in filling holes and gaps that would take many days to dry out and have shrinkage cracks using the drying compound. Setting type compounds are available in setting times ranging from 5 to 210 minutes and types that bond extremely well and are very hard and types that are soft and easy to sand. Once mixed with water, the setting type must be used before it sets; any leftover is wasted and if not enough is mixed, another batch is needed to finish the job, and all tools must be very clean or the compound may set up prematurely. This makes the setting type compounds harder and more time consuming to prepare, but they set quickly. Setting type compounds can be used at temperatures down to 45 °F (7 °C). Some drywall professionals use setting type mud for the first coat and a drying type for the thinner finish coat. Setting type compounds do not soften when they get wet, thus are better for moist environments, such as bathrooms.
What is tapeless joint compound?
Tapeless drywall joint compound. In recent years, some companies in Europe, Australia and Canada have developed a new type of drywall joint compound called tapeless joint compound. It can be applied to the joints directly without either paper tape or fibreglass mesh tape.
What compound to use for bedding tape?
While joint compounds are used for bedding tape and initial layers overtop, it is best to apply topping compound for finish layer (s) that level and sand more evenly. Both require thinning for practical application.
What is a compound in drywall?
The compound is a complex combination often including water, limestone, expanded perlite, ethylene-vinyl acetate polymer, att apulgite, and other ingredients. The delicate mixture of compounds gives it a creamy texture that spreads easily onto drywall surfaces and then hardens as the moisture evaporates.
What type of joint compound is drying type?
Drying type joint compounds are vinyl based and harden when they dry by evaporation.
Hazard
Construction workers who sand drywall joint compound are often exposed to high concentrations of dusts and, in some cases, respirable silica. Drywall joint compounds are made from many ingredients (i.e., talc, calcite, mica, gypsum, silica).
Controls
A recent NIOSH Health Hazard Evaluation (HHE) found that drywall sanders were exposed to as much as 10 times the permissible exposure limit (PEL) of 15 mg/m3 for total dust set by the Occupational Safety and Health Administration (OSHA).
For More Information
To obtain more free information about controlling this hazard or for information about other occupational health and safety issues:
Acknowledgments
The principal contributors to this publication were Kenneth R. Mead, P.E.; Aubrey K. Miller, M.D.; and Jerome P. Flesch, M.S. Desktop publishing was provided by Vanessa Becks, Kristina Dragon, and Susan Kaelin.
How long does joint compound last?
If storing, cover leveled surface of joint compound with approximately 1/2" of clean water and cover container tightly. Pour off water before reusing joint compound. Do not store in direct sunlight and protect from extreme heat and cold. The shelf life of an unopened container is up to nine months under proper storage conditions.
What is the silica rule?
The silica rule is a jobsite regulation designed to protect workers from all RCS exposures above 50 µg/m 3, which is the PEL as defined by OSHA. Under normal jobsite conditions, industrial hygiene testing conducted by a third-party, indicated that the sanding of Sheetrock® Brand ready-mixed joint compound, unless otherwise specified on packaging and within the SDS, does not contain RCS above the PEL.
What is the new OSHA rule for silica?
OSHA’s new silica rule is meant to protect workers from exposure to respirable crystalline silica (RCS) on jobsites. The Rule establishes a new 8-hour time-weighted average (TWA) Permissible Exposure Limit (PEL) of 50 µg/m 3 , an action level (AL) of 25 µ g/m 3 and a host of ancillary requirements .
How to repair a blistered joint?
The best way to repair blistering joints is to open up the blistered area by slitting the tape. Fill the cut with joint compound and press tape back in place with knife blade.
Is USG a silica free compound?
There are no ready-mixed joint compounds that exist that are 100% “ silica free.” However, the amount of respirable crystalline silica in USG joint compounds is low.
Does USG have control over additives?
USG has no control over the manufacture and quality of additives manufactured by others. Note - For taping and finishing joints, water can be added as necessary. USG recommends adding water in increments of a half-pint to avoid over thinning. See USG Technical Information Sheet J1716 for more information.
Does joint compound fire rating?
Joint compound does not have a fire rating by itself, but does meet ASTM C475. When fire testing a wall the fire rating is not for individual products, but for all the system components together. USG Joint Compounds are used in numerous fire-tested assemblies. These are outlined in USG Publication SA100 Construction Selector.
