Critical Effect Posted on 6th November 201523rd July 2021 by ThePD (The Project Definition) Critical Effect in hazardous chemical exposure is the first adverse effect that occurs as the dose rate increases. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in HSE and tagged hazard. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.