There are none for student loans. If you file bankruptcy they're the only kind of debt that you can't discharge.
This isn't true. 11 USC 523 contains a long list of non-dischargeable debts, including child/spousal support obligations, certain taxes, and debts incurred by fraud or willful injury.
You can get student loans discharged. It's a misconception that many believe, even lawyers. It's just very, no, extremely, difficult to do so.