Contains fiber glass wool, a possible cause of cancer if inhaled.
Based largely on the animal implantation experiments and following its mandatory classification protocol, IARC classified glass wool as category 2B, "possibly carcinogenic to humans." IARC regards it as prudent to treat a material for which there is sufficient evidence of carcinogenicity in animals as if it is a possible carcinogen to humans.

Carcinogenicity:
Ingredient: Fiber glass wool, Glasswool (respirable size)
NTP: Listed as 2, reasonably anticipated to be a carcinogen, sufficient evidence from studies in experimental animals
IARC: Classified as 2B, possibly carcinogenic to humans

Conditions of Flammability:
Facings on these products may burn. Care should be taken not to leave facing exposed when working close to an open flame.

Unusual Fire and Explosion Hazard. Decomposition Products: These products contain a cured phenolic-based binder. The binder and kraft facing in a fire situation may emit toxic fumes and smoke containing carbon dioxide, hydrogen chloride, carbon monoxide and molecular fragments of hydrocarbon particles, carbon-hydrogen-nitrogen and nitrogen-oxygen compounds.

How Does Exposure Occur?
"Facts About Fiber Glass - Lung Hazards on the Job"
American Lung Association

Workers using fiberglass may be exposed to airborne fibers from the fiberglass itself and to various chemicals associated with using it.
Fiberglass - Direct contact with fiberglass materials or exposure to airborne fiberglass dust may irritate the skin, eyes, nose and throat. There is a possibility that these fibers cause permanent damage to the lungs or airways, or increase the likelihood of developing lung cancer. Inhaling the fibers may irritate the airways, resulting in cough and production of excess mucus, a condition known as bronchitis.

Epoxy Resins - Epoxy resins are chemicals used in lacquers, varnishes and plastics, or in combination with other components to form plastics. They are also used to strengthen, harden, or give flexibility to fiberglass.

Breathing epoxy resins may cause chest tightness, shortness of breath or wheezing. Skin contact can cause rash.

Styrene - Styrene is part of the polyester resin used with fiberglass. It is extremely irritating to the eys and nose at low concentrations; at higher concentrations it causes headache, dizziness, and sometimes nausea.

Acetone and MEK (Methyl ethyl ketone) - Acetone and MEK are commonly used solvents in fiberglass lay-up and spray-up. They are irritating to the eyes, nose and throat. Inhaling the vapors may cause drowsiness, breathing difficulties, and more serious damage to the lungs and nervous system.