Is it the same as the saturation pressure was or it is lesser?

I saturated ABS sheet at 5 MPa for 48 hours and subsequently I heated it at 120 degree C in hot glycerine bath. The cell size obtained was 8 microns and expansion ratio obtained was 16 (SEM image attached).

I wish to know the pressure inside these newly formed cell just after foaming has occurred. Is the pressure inside the cell at 5 MPa or less ?

Thank you researchers in advance for replying with your valuable comments.