An exit route must meet minimum height and width requirements. [29 CFR 1910.36(g)] The ceiling of an exit route must be at least seven feet six inches (2.3 m) high. Any projection from the ceiling must not reach a point less than six feet eight inches (2.0 m) from the floor.
4. adjective. In Britain, first-class postage is the quicker and more expensive type of postage. In the United States, first-class postage is the type of postage that is used for sending letters and postcards. Two first class stamps, please. The price of mailing a first-class letter will not be increasing this year.
First-Class Mail includes letters, postcards, large envelopes (called flats), and small packages, providing each piece weighs 13 ounces or less. First-Class Mail is processed by the USPS with the highest priority. It goes to the front of the line; ahead of the other classes of mail. Locally, First-Class will typically be delivered within one to two business days, and nationally it will be delivered in three business days.