The increase will take most of the workers from the current federal minimum wage of $3.35 an hour to $3.80.

There are some exceptions. Employers may deduct up to $1.90 an hour from those who get some of their income from tips. Those who work for rent-controlled apartments may receive as little as $3.50. And those under the age of 18 may be paid the federal minimum of $3.35.

The increases were approved in November by the D.C. Wage-Hour Board. Under D.C. law, minimum wages are set for specific occupational groups--not for all workers, as the federal wage law provides. Employes are paid whichever minimum wage--federal or D.C.--is higher, except for very small businesses, where the lower rate often may apply.

When the new wage order was adopted, a consultant to five fast-food chains predicted that it would trigger the elimination of 700 jobs held mostly by young people and would force an increase in prices.

Technically, about 45,000 workers are covered by the new wage order, but most already are paid above the minimum wage, many because they are members of a union that has negotiated higher pay and others because their employers voluntarily pay at a higher level. About 12,000 can expect pay increases as a direct result of the order, a board spokesman said.