What you need to know about setting off fireworks in DC
From the website of the Metropolitan Police Department:
Whether you're celebrating Independence Day or the New Year, a backyard barbecue or other family occasion, it is important to understand the laws regulating fireworks use in the District of Columbia. Find out what fireworks are permitted and prohibited in DC.
Article 27, DC Register, F-2700.1.1: The manufacture, storage, display, sale, setting off, or discharge of any firework listed below is prohibited in the District of Columbia.
Firecrackers of any kind or description
Any firework that explodes, such as cherry bombs, salutes, Roman candles, floral shells, artillery shells
Any firework intended to move after the piece is placed and fired; such as bottle rockets, parachutes, buzzbombs, pinwheels, helicopters, jumping jacks
Sparklers more than 20 inches (50mm) in length
Any firework that contains mercury, arsenic, tetryl, phosporous, sulphocyanide, magnesium, potassium picrate, gallic acid, chlorate of potash and sugar, or any highly oxidizing agent
Any firework having a side fuse, or a fuse inserted at any point along the length of the firework
Any firework found by the code official to be dangerous to the safety of persons or property
Article 27, District of Columbia Register, F-2700.1.2): The fireworks listed below are permitted to be stored, displayed, sold, delivered, used, and possessed in accordance with the provisions of this article.
Any firework specifically excepted in this article
Toy paper caps containing not more than twenty-five hundredths (0.25) of a grain of explosive composition per cap
Sparklers not more than 20 inches (50mm) in length
Box fires, fountains
Dip-sticks, non-poisonous snakes
Paper novelty items, colored lights
And here is a handy info sheet you can download and print: