The answer is actually surprisingly simple once you know where to look for help! The International Firestop Council (IFC) has developed guidelines for evaluating engineering judgments for a range of firestopping applications. The IFC is a not-for-profit association of firestop inspectors, manufacturers and users of fire protective materials. This broad base of membership allows the IFC to draw from a diverse pool of knowledge and provide impartial guidance to the firestopping industry.
The IFC engineering judgment guidelines are divided up into a number of different categories dependent on the specific type of firestop being installed. There is a general document that is suitable for all common applications including penetrations, joints, perimeter fire barrier systems and duct enclosure systems. There are also guidelines specifically tailored for evaluating EJs covering air duct, grease duct or perimeter fire barrier systems. These more focused documents provide commentary regarding the intent of these firestop systems and an overview of the testing standards used to evaluate them. Obviously each project has its own specifications and code compliance enforcement, but the IFC engineering judgment guidelines are a valuable resource for all stakeholders who are in a position to determine whether an EJ has merit or not.