Both Plan B pills can be taken at the same time with no decrease in effectiveness or increase in side effects. Plan B should be taken within 5 days (120 hours) of unprotected sex and can reduce the risk of pregnancy up to 89%. But it is more effective the sooner you take it.
A hazard and operability study (or HAZOP) is a systematic, critical examination by a team of the engineering and operating intentions of a process to assess the hazard potential of mal-operation or mal-function of individual items of equipment and the consequential effects on the facility as a whole.
zep - a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States.