Blown insulation, or blown-in insulation, is a technique used to insulate odd-shaped and hard-to-reach crevices and cavities. Cellulose, rock wool and fibreglass are common blown-in insulating materials that are blown in by specialised blowers, or machines, to fill up a designated area---typically walls and floors. Blown insulation is effective at insulating spaces and cutting down energy costs. It is, however, associated with certain risks and hazards which you must appropriately analyse.
Asbestos is a mineral fibre that was used extensively in the past for a variety of construction purposes. It was added to building materials to impart greater strength and heat resistance characteristics. Asbestos use surged in the mid-20th century and approximately 27.5 million people were exposed to the substance between 1940 through 1970, according to Asbestos.net. Asbestos is linked with a number of diseases and illnesses, including lung cancer, asbestosis and mesothelioma. While most newer construction material and insulation parts do not contain asbestos, older insulation, such as that commonly found in attics and neglected basements, may contain traces of the substance. When insulation gets disturbed or damaged due to demolition, remodelling or repair, it may become airborne and lodge in the lungs to cause severe respiratory and potentially life-threatening illnesses.
Vermiculite is a mineral used commonly in insulation, construction and gardening. Mines in Libby, Montana were among the major sources of vermiculite in the 1970s and 1980s. According to the Government of Wisconsin website, more than 70 per cent of worldwide vermiculite was mined from Libby. According to the Environmental Protection Agency (EPA), 940,000 homes in the U.S. contained Libby-mined vermiculite in the year 1985 alone. It was later found that Libby ores were heavily contaminated with asbestos. Particles of blown vermiculite insulation, when inhaled, has extensive health consequences; the effects of some manifest years after initial exposure.
Urea formaldehyde foam insulation (UFFI) was a common material that was blown into difficult-to-reach cavities within walls for the purpose of insulating them. Formaldehyde is a colourless, pungent gas that is toxic and a lung irritant in larger quantities. Exposure to excessive formaldehyde results in watery eyes, throat and nose irritation, respiratory distress, cough, skin irritation, nausea, dizziness and headaches. UFFI was extensively used in the 1980s, and homes insulated with the substance are a cause for concern. Moisture or water further deteriorates UFFI, releasing noxious formaldehyde into the indoor atmosphere. Remove all deteriorating and old blown UFFI insulation, and dispose of it appropriately.