Risk Assessment for CO2 gas used in freezing fish and fish fillet

Dear all 

Good day 

Expert advice requested for CO2 gas in tunnel freezer for fish fillets. Is it necessary to prepare risk assessment to comply FSC of SQF edition 9.

Can anybody share risk assessment for co2 gas used in freezing fish and fish fillet plz

I don't know why you'd need a RA

You will need documentation for the process

How CO2 Works in a Cryogenic Tunnel Freezer:
 
Liquid CO2 acts very differently in a freezer than liquid nitrogen. CO2 is piped to the tunnel as a high pressure liquid (300 psi), but once it exits the injection orifice, it instantaneously expands into a mixture of gas and tiny dry ice solid particles (at -109F). The dry ice solid, commonly referred to as dry ice "snow" is driven into the surface of the food product, where the heat from the food product rapidly causes the dry ice to "sublimate" or phase directly from a solid into a gas. The refrigeration effect of CO2 occurs as a result of the latent heat of sublimation (246 BTUs per lb of solid CO2 or more commonly represented as 120 BTUs per lb of liquid CO2). Where nitrogen tunnels are able to use refrigeration from both the vaporizing of liquid and warming up the vapor, CO2 tunnels are primarily designed to use refrigeration from dry ice snow sublimation. A CO2 flat belt tunnels look much the same as a convention LN2 tunnel, except that LCO2 is injected on the product immediately after it enters the tunnel and almost continuously for about 70% of the length of the tunnel.

Thank you @scampi