There are Many Reasons you can remove/dispose of your old spray foam insulation:

1. Your old insulation has become less effective or useless.
2. Your home has excessive dust and you or a family member suffer from allergies.
3. You may have vents or openings such as bathroom fans, recessed and wall vents through which dust particles can enter your home.
4. Your insulation may have become contaminated by rodents, insects and/or water damage.