Medical sharps, including hypodermic needles used for insulin injections, are not regulated by the Federal EPA under the Resource Conservation and Recovery Act (RCRA). However, EPA has published guidelines on the safe disposal of medical sharps.
The following documents may be useful:
Community Options for Safe Needle Disposal, EPA530-K-04-001 (PDF) (8 pp., 590 KB)
For more information, see the medical sharps web page.