No Leaks is a campaign achievement/trophy in Call of Duty: Black Ops. It requires the player to bypass the Nova 6 section on "Rebirth" without dying. The player wears a gas mask, if damage is taken, the gas mask cracks. If the gas mask breaks, then the player will die of the poisonous Nova 6 gas. This can be difficult because only health regenerates and the mask condition does not restore and stays as it is until the biohazard zone is exited.
Note: If player's ally glitches and does not drop the Strela-3 during the chopper attack (he is supposed to die from enemy fire), player can simply team kill him, causing a checkpoint reload and the player will still be eligible for No Leaks.