Insulation Health & Safety
When you’re thinking about any product for your home, health and safety are obviously a priority—and insulation is no different. When it comes to health and safety properties, not all types of insulation are equal. Here is an outline of some general considerations for different insulation types.
One thing to note is some of these considerations may be covered by code. When the product manufacturer’s instructions conflict with your local code authority’s regulations, follow the more stringent of the two.
Fire resistance is, naturally, a primary consideration for insulation in a home. Some factors to consider when comparing insulation types for fire safety are:
Mineral fiber insulation
Materials are noncombustible, and remain so for the life of the product. They require no additional fire-retardant chemical treatments, and in fact, some unfaced mineral fiber products (fiberglass, rock wool, and slag wool) are accepted as fire stopping and as a fire block material.
Products are largely made of newspaper, which is highly combustible. Needs to be heavily treated with fire-retardant chemicals prior to installation.
Spray foam insulation
Spray foam and combustible foamed plastic insulations must be protected by adequate thermal barriers and can not be left exposed to the living environment.
Not all insulation materials have undergone the same level of testing and scrutiny when it comes to health and safety.
Mineral fiber insulations
The International Agency of Research on Cancer (IARC) has stated that mineral fiber (fiberglass, rock wool, and slag wool) thermal and acoustic insulations are not considered classifiable as to carcinogenicity.
Questions about the health and safety aspects of cellulose insulation persist in the building industry, because very little medical or scientific testing of the products has been conducted. There’s still a need for full toxicological testing of dust from cellulose building insulation and dust from pure cellulose fibers. Safety conclusions can’t really be drawn until extensive testing is completed.
The safety of spray foam insulation is still being evaluated. If you’re worried about the impact of chemicals on your home and family, you’ll want to learn more about the chemical components of spray foam. According to the California Department of Toxic Substance Control, one of the main ingredients in spray foam, methylene diphenyl diisocyanate, could post a number of health risks, including lung damage and asthma.
Different spray foam manufacturers publish different guidelines for length of evacuation times during installation and curing. Note that there are no established evacuation timelines from any government agency.
Mould can grow in any environment where there’s moisture and food for mould spores, so many organic materials can be food for mould. Even though some products claim to be mould-resistant, it can grow on ANY surface under moist conditions if organic material exists to support the spores. Some considerations when insulating to avoid mould are:
- Mineral fiber insulation is inorganic, and therefore doesn’t feed mould growth
- Cellulose and spray foam insulation are composed of organic material, so they can be a food source for mould, unless properly treated with chemicals or other agents that can prevent or inhibit mould growth
Risk of corrosion to pipes, wires, and fasteners is a factor to consider at all phases of home building or improvement, and insulation is no exception. Your insulation choices can affect the possibility of corrosion, including:
- Fiberglass, rock wool, and flag wool insulation are not corrosive and contains no chemicals that can corrode pipes and wires
- Cellulose insulation contains certain chemicals routinely applied as a fire retardant to some cellulose insulation. These chemicals, particularly the sulfates, can cause the corrosion of pipes, wires, and fasteners under some conditions
 K. Sheppard, R. Weil, and A. Desjarlais, “Corrosiveness of Residential Thermal Insulation Materials Under Simulated Service Conditions,” Insulation Materials, Testing and Applications, D.L. McElroy and J.F. Kimpflen, Eds. (ASTM: Philadelphia, PA, 1990), pp. 634-654; “Corrosiveness Testing of Thermal Insulation Materials – A Simulated Field Exposure Study Using a Test Wall, Report ORNL/Sug. 78-7556/4, September 1988