American Petroleum Institute

Management of Process Hazards - FIRST EDITION
 N RP 750

Annotation

APPLICATIONS

This recommended practice is intended for facilities that use, produce, process, or store the following substances:

a. Flammable or explosive substances that are present in such quantity and condition that a sudden, catastrophic release of more than 5 tons of gas or vapor can occur over a matter of minutes, based on credible failure scenarios and the properties of the materials involved (see Appendixes A and B).

b. Toxic substances that have a substance hazard index (SHI) greater than 5000 (see Appendix C) and that are present in amounts above a threshold quantity.

Toxic substances commonly handled by the petroleum industry that meet the SHI criteria include hydrogen sulfide (H2S), chlorine (CI2), hydrogen fluoride (HF), and ammonia (NH3). The following facilities are examples of those to which this recommended practice may be applicable, based on the criteria of 1.3.1.1, Item b:

a. Hydrogen sulfide and sulfur recovery facilities.

b. Chlorine handling and storage facilities.

c. Hydrogen fluoride alkylation and storage facilities.

d. Ammonia storage and refrigeration facilities.

An illustrative list of substances, along with calculated SHI values, is included in Appendix C as Table C-1.

APPLICABILITY OF RECOMMENDED PRACTICE

This recommended practice was developed for refineries, petrochemical operations, and major processing facilities. The following operations are not within the scope of this recommended practice: