Are there any health or safety concerns?

Cellulose is primarily wood-pulp fibers, and a few other subtances that have been well-known to the scientific community for decades.  One such substance is boric acid, which is used as a fire retardant.  Boric acid has a toxicity roughly similar to common table salt.  None of the substances used in the manufacture of cellulose insulation pose health hazards.  Loose-fill cellulose installation can create dust, a potential respiratory irritant.  Not  only do we use a special  low-dust formula, we also apply Stabilized Cellulose, which is cellulose to which a glue has been applied.  All that is required is a simple dust mask during installation.