501(c) organization

A 501(c) organization, also known colloquially as a 501(c), is a tax-exempt nonprofit organization in the United States. Section 501(c) of the United States Internal Revenue Code (26 U.S.C. § 501(c)) provides that 29 types of nonprofit organizations are exempt from some federal income taxes. Sections 503 through 505 set out the requirements for attaining such exemptions. Many states refer to Section 501(c) for definitions of organizations exempt from state taxation as well. 501(c) organizations can receive unlimited contributions from individuals, corporations, and unions.

The most common type of tax-exempt nonprofit organization falls under category 501(c)(3), whereby a nonprofit organization is exempt from federal income tax if its activities have the following purposes: charitable, religious, educational, scientific, literary, testing for public safety, fostering amateur sports competition, or preventing cruelty to children or animals. The 501(c)(4) and 501(c)(6) categories are for politically active nonprofits, which have become increasingly important since the 2004 presidential election.

C4

C4, C04, C.IV, C-4, or C-04 may refer to:

People

Biology

Vehicles

Aircraft

C-4 (explosive)

C-4 or Composition C-4 is a common variety of the plastic explosive family known as Composition C. The British version of the explosive is known as PE-4 (Plastic Explosive). C-4 is composed of explosives, plastic binder, plasticizer to make it malleable, and usually a marker or odorizing taggant chemical.

C-4 has a texture similar to modeling clay and can be molded into any desired shape. C-4 is stable and an explosion can only be initiated by the combination of extreme heat and shock wave from a detonator.

Characteristics and uses

Composition

The Composition C-4 used by the United States Armed Forces contains 91% RDX ("Research Department Explosive", an explosive nitroamine), 5.3% dioctyl sebacate (DOS) or dioctyl adipate (DOA) as the plasticizer (to increase the plasticity of the explosive), 2.1% polyisobutylene (PIB, a synthetic rubber) as the binder, and 1.6% of a mineral oil often called "process oil". Instead of "process oil", low-viscosity motor oil is used in the manufacture of C-4 for civilian use.