Understanding Spray Insulation Foam

Spray polyurethane foam (SPF) insulation has become more popular over the past few years for both commercial and residential applications because it helps reduce heating costs and decreases the use of fossil fuels. This type of insulation is more energy efficient than traditional fiberglass insulation, and it is usually cheaper to install and purchase. Therefore, many homes and buildings opt to use this type of insulation over its fiberglass alternative.

While demand for this insulation has increased, there are also a growing number of health effects and safety concerns. Spray insulation is often produced on the jobsite and not in a production facility. It is made by mixing chemicals together that react quickly and expand to create a foam that air seals, insulates, and offers a vapor barrier or barrier to moisture.

When installed properly, SPF can form a continuous barrier around corners, walls, and modeled/contoured walls. This substance is known for its great air sealing qualities and is a top choice for creating an air barrier or blocking unwanted air leaks from cracks, seams, and joints. It’s widely used as a gap filler to seal gaps and cracks and as a means to prevent energy loss. This insulation also resists heat transfer.

How is Spray Foam Made?

Two sets of chemicals are mixed together on-site during the installation. Professionals commonly refer to the chemicals as “A-Side” and “B-Side” due to the separate containers they come in. These chemicals must be stored separately until they are properly mixed. Mixing the two sets of chemicals triggers a rapid chemical reaction that creates the foam.

What Are the A Side and B Side of Spray Foam Insulation?

  • A-Side:The A Side typically consists of a 50/50 mixture of methylene diphenyl diisocyanate (MDI) and polymeric methylene diphenyl diisocyanate (pMDI). Exposure to these chemicals, also known as isocyanates, can cause severe skin problems and respiratory damage. According to the EPA, these types of chemicals were reported to be the leading cause of work-related asthma, and in some cases reactions have been fatal. Symptoms during exposure, or immediately after, can include shortness of breath, coughing, wheezing, irritation of the lungs and eyes, fever, sore throat, tightness in the chest, headaches, joint pain, and a stuffy nose.
  • B-Side: This mixture consists of a polyol resin blend and smaller amounts of amine and/or a metal catalyst, blowing agent, surfactant, and flame retardant. This mixture helps control the stage of the chemical reaction that creates the foam bubbles and some of the protective characteristics of SPF like flame retardancy.

What’s the Difference Between Open Cell and Closed Cell Foam Insulation?

What is a spray foam cell?

Spray insulation is referred to as open cell or closed cell due to the nature of the small bubbles (cells) that make up the foam. The foam cells can be open, allowing air and liquids to permeate, or closed, remaining impermeable to liquids and gases.

Open Cell Foam vs Closed Cell Foam

Open cell and closed cell foam are two different types of spray foam insulation. Both have different strengths and weaknesses depending on their application, the surrounding environment, and/or the goal of the insulation project.

Open cell foam: Open cell foam is represented by cells that aren’t completely encapsulated or closed off. This means the cells, or bubbles, are purposely left open allowing for air and moisture to penetrate. The “hollow” and opened cells create a softer, more flexible material. This type of foam insulation is known for its ability to expand—this makes useful for insulating hard to reach areas like crawl spaces, nooks, cracks, and corners for an airtight environment. Most open cell foams are deemed air impermeable at a minimum of 3.5”. It’s also great for soundproofing, however, it is not ideal for locations with extreme weather because it is not as good of an insulator. This type of spray foam insulation is typically more affordable than closed cell foam.

Closed cell foam: This foam is made up of cells that are completely closed meaning air and moisture cannot enter or permeate the cells. Cells are pressed together tightly, further preventing air and moisture from penetrating the foam. Because the cells are fully closed and tightly packed, this foam is more dense, rigid, and stable. This also makes it is a better insulator, water-resistant, and a great vapor barrier. It is ideal for large-scale insulation projects where spacing is limited because at around 1.5” thick, closed cell foam is considered air impermeable. With the foam curing less thick, it can be layered multiple times to achieve a higher level of protection than open cell foam in a standard wall.

Other key differentiators between these two types of SPF include:

Density: Due to how tightly packed the cells are in closed-cell foam, this foam is more dense than open cell foam. Closed cell foam can be over three times as dense as open cell foam with a common density of about 1.75 pounds per cubic foot or more. Open cell foam ordinarily has a density of about 0.5 pounds per cubic foot.

R-Value: The R-value refers to how well the foam insulates or resists heat flow. The higher the R-value, the better the foam (or layers of foam) keep heat in or out of a structure. Due to its density and cell structure, closed cell foam has a higher R-value than open cell foam making it a better insulator.

Expansion: In terms of application, this characteristic is a critical difference. Closed cell foam expands to about 1” thickness when sprayed and cured. This means that in tighter spaces, multiple layers can be applied to achieve a higher total R-value. Meanwhile, open cell foam expands to about 3” thick, so usually only one layer or application of foam can be used in standard walls.

PPE for Spray Foam Insulation

If you are installing SPF insulation, you must have the right spray foam safety gear to protect yourself. Insulation will need to be installed correctly, so that there is no risk to the building owners and those who enter the home after the insulation project is complete. There are also certain factors that can impact the curing rates that workers need to know, since it may still not be safe to enter the building. For example, toxic fumes and particles can linger in the air or travel to other areas of a building. Ambient conditions, such as humidity and temperature, can also play a role, as well as poor applicator technique.

Recommended Spray Foam Insulation Protective Gear Includes:

  • Respiratory protection: Air-purifying respirators (APR) and powered-air purifying respirators (PAPR) for exterior applications; Supplied-air respirators (SAR) for interior applications.
  • Eye protection: Safety goggles or safety goggles in combination with a face shield.
  • Hand protection: Chemical-resistant gloves made of strong rubber such as nitrile, neoprene, butyl, or PVC.
  • Foot protection: Chemical-resistant boots and chemical-resistant boot covers
  • Head protection: Hooded respirator or coveralls with an attached hood.
  • Skin protection: All exposed skin must be covered. Disposable, chemical-resistant coveralls that protect against sprays and mists should be worn. Select a coverall with an attached hood when not wearing a hood respirator.

Finding the right PPE will depend on the type of anticipated exposure. The type of PPE worn for other jobs may not protect you enough when it comes to spray insulation. You also want to choose the right durability and appropriateness of PPE for the tasks. The third thing to consider is the fit.

Managers must ensure that the needs of PPE are assessed by a person who is competent to judge what methods of risk control can offer better protection for health and safety. Professional advice should be attained to identify the suitable types of PPE for the tasks that are supposed to be carried out. Training should be provided to supervisors and employees to make sure they understand the proper selection, use, fit, and maintenance of PPE.

According to OSHA regulation 3.35,employees must use protective clothing or equipment in the way he or she has been instructed to do so and not misuse or damage the clothing. As soon as possible after becoming aware of any damage or malfunction, employees must notify the person who is providing the clothing to either fix the damage or clean and sterilize the equipment.

PPE for spray foam insulation is needed for the applicators, helpers, and the adjacent workers who may be entering the work area. The appropriate clothing depends on the potential for exposure, but applicators should wear disposable coveralls to prevent mist and spray from contacting clothing and skin—exposed skin should not be visible. When not wearing a hood respirator, the coverall should have an attached hood or head cover. Properly fitting gloves should be made of a chemical-resistant rubber to protect against chemical exposure.

Eye protection is needed to prevent chemical splash from entering the eyes, as well as contact with vapors and aerosols that could be present while spraying. Wearing contact lenses while applying SPF is discouraged. Full-face air purifying respirators may be appropriate for exterior applications but may not be appropriate for confined spaces.

In addition to wearing protective clothing, workers should review label and product information for hazard directions and safe work practices. They should also ensure that health and safety training is complete to prevent eye, skin, and respiratory exposure throughout the project.

Why Use Disposable Clothing?

Disposable protective clothing has many advantages. Some jobs are better suited for disposable clothing because they become too dirty or useless once they are used. Using disposable clothing allows you to save time cleaning and protects against spreading any other contaminants. With disposable clothing, you don’t have to worry about damaging any of the more expensive, multiuse PPE. Materials that are used in multiuse protective clothing can also wear down over time with laundering and repeated use. However, with disposable protective clothing, it is made of durable materials that are not subject to the effects of reuse, transport, laundering, storage, and decontamination.

International Enviroguard has a variety of disposable protective clothing options for spray foam insulation installation and other SPF applications. Our selection of disposable spray suits offers chemical resistance and particulate protection while keeping workers more comfortable than traditional suits. Our spray foam safety gear has been tested using protection standards for repellency and penetration and is engineered for a better fit for heavy-duty work with less tearing and ripping.