# What are Criteria or regulations for stopping of COW or crude oil washing operation?

1. If the oxygen concentration in the tank exceeds 8% (volumetric ratio)
2. If supply is no longer possible because of failure of the inert gas system
3. If the pressure within the tank has dropped below +1.961 kPa (+200 mmAq)
4. If tank pressure rises and approaches the predetermined pressure of the breather valve
5. If the charterer or the terminal has specified restrictions on oxygen concentration that are stricter than the criteria given above, then those restrictions take priority.