Posted By Nick House Hi Mark, Typically, fibreglass wool insulation can cause short term irritation to the skin, eyes and upper respiratory tract. Although glass wool fibres are generally between 5 and 10 microns in diameter, some are found to be less than 3 microns in diameter, and are fine enoughto be inhaled into the lungs. Although tests show that glass wool can cause cancer in certain animals, it is yet to be proved whether humans are susceptible to the same dangers. My advice is that anyone using fibreglass wool insulation should wear suitable ppe such as overalls, gloves (creating a seal at the wrists, goggles and a suitable dust mask. Hope this helps, Nick.