Why limit VOC or volatile organic compound emissions to the atmosphere?

VOCs are a pollutant to the air and act as a precursor to the formation of   Tropospheric Ozone and commonly termed Smog.

Thus, to control this emission, there are four criteria that impact on the extent and rate of evolution of gaseous VOC from crude oils and its subsequent release to atmosphere. These are:

1. the volatility or vapour pressure of the crude oil;
2. the temperature of the liquid and gas phases of the crude oil tank;
3. the pressure setting or control of the vapour phase within the cargo tank; and
4. the size or volume of the vapour phase within the cargo tank.

Note:

Each of these criteria are defined and briefly explained above together with any interaction between the criteria for general operational circumstances.