The issue with Impaired.org is that it emphasizes a negative quality. .ORG would be favored by groups for people with various kinds of disabilities, but those groups would want to emphasize something positive with their branding. One group does identify itself using the word "impaired" -- specifically, people who are hearing impaired. But without the word "hearing", "impaired" on its own fails to identify that group adequately.
Long story short, I think this domain will wait a long long time before it gets purchase inquiries. It won't be in high demand. If you find an opportunity to sell, then sell.