NACE MR 0175/ ISO 15156, Part 2: Cracking Resistant Carbon and Low Alloy Steel and use of Cast Irons, Section 7.1.1: The selection of material for SSC resistance for P(H2S) below 0.05 psi is not considered in detail in this part%E2%80%A6%E2%80%A6%E2%80%A6Normally no precaution is required of steel for the use under these conditions%E2%80%A6%E2%80%A6%E2%80%A6 NACE MR 0175/ ISO 15156, Part 2: Cracking Resistant Carbon and Low Alloy Steel and use of Cast Irons, Section 8: The equipment user shall consider HIC/ SWC as defined in NACE MR 0175 when evaluating Carbon Steel Flat Rolled products for sour service environment containing even trace amount of H2S and shall consider HIC/ SWC testing of these products. From the above references of the NACE MR 0175, it is understood that no special consideration is required for material selection for SSC resistance if the partial pressure of H2S is less than 0.05 psi. NACE however require HIC/ SWC testing of flat rolled steel products if the process media contain any amount of H2S irrespective of partial pressure of H2S. I have seen that HIC/ SWC had not been asked/ carried out in many projects inspite of having requirement of NACE compliance. NACE language "SHALL CONSIDER........EVEN TRACE AMOUNT OF H2S" have raised some doubts in the mind. Any advise of the interpretaion of NACE for HIC/ SWC requirements??