Probably because the chemicals they were using are pretty nasty and were used in high volumes. They were doing a lot of damage to the environment and there are

Probably because the chemicals they were using are pretty nasty and were used in high volumes. They were doing a lot of damage to the environment and there are alternatives. They just haven't been approved yet for use by the navy. It's not a good look to continue using damaging, outdated methods because your bureaucracy is so bad that can't utilize new technology.