To summarise:
Must admit that thus far I've used only white oxygen compatible grease on my rebreather. Silicone grease would be much easier to apply and use for O-rings and connectors, especially large O-rings such as around the lid.
- In high-pressure components in contact with high oxygen percentages, use oxygen compatible grease -- as silicone grease poses a significant fire risk as it is fuel and could be ignited by a sudden increase in oxygen rich gas pressure (compression ignition / diesel effect)
- In low pressure components (ADV, loop hose connectors, rebreather lid, etc.) normal silicone grease poses no risk of fire as there is no risk of compression ignition as there's insufficient pressure change to increase the temperature.
Must admit that thus far I've used only white oxygen compatible grease on my rebreather. Silicone grease would be much easier to apply and use for O-rings and connectors, especially large O-rings such as around the lid.