| Paper shredders are used to cut paper into very fine | | | | storage capacity of 6,000 to 15,000 pounds of |
| strips or tiny paper chips. Government organizations, | | | | shredded paper. Office paper is the typical material |
| businesses, and private individuals use shredders to | | | | being shredded, but with increasing security concerns |
| destroy private, confidential, or sensitive documents. | | | | customers also request shredding of CDs, DVDs, hard |
| Privacy experts often recommend that individuals | | | | drives, credit cards, uniforms, among other things. |
| shred bills, credit card and bank account statements, | | | | Shredding services |
| and other documents that could be used by thieves to | | | | Due to information privacy laws like FACTA and |
| commit fraud or identity theft. | | | | HIPAA, the volume of shredding at the typical business |
| After the Supreme Court decision in California v. | | | | has increased dramatically. To reduce costs many |
| Greenwood, in which the Supreme Court of the United | | | | companies outsource their shredding to shredding |
| States held that the Fourth Amendment does not | | | | services. These companies either shred on-site, usually |
| prohibit the warrantless search and seizure of garbage | | | | with mobile shredder trucks, or off-site. All shredded |
| left for collection outside of a home, paper shredders | | | | paper is then sent to a paper mill. |
| became more popular among US citizens with privacy | | | | Unshredding |
| concerns. | | | | In some cases, it may be possible to reassemble the |
| Types of shredders | | | | pieces of shredded documents. If the shreds are not |
| Shredders range in size and price from small and | | | | disturbed, the "noodles" or particles that belonged to |
| inexpensive units meant for a few pages, to large units | | | | the same document tend to stay close to each other. |
| used by commercial shredding services that costs | | | | Furthermore, when the documents are fed to the |
| hundreds of thousands of dollars and can shred | | | | shredder in a way that the lines of text are not |
| thousands of pounds an hour. Some shredders used | | | | perpendicular to the shredder blades, portions of text |
| by commercial shredding service are built into a | | | | may remain legible on the stripes. |
| shredding truck. | | | | Shredded documents can be reassembled manually. |
| These machines are classified according to the size | | | | After the Iranian Revolution and the takeover of the |
| and shape of the waste they produce. The shred | | | | U.S. embassy in Tehran in 1979, Iranians enlisted local |
| waste that remain of the documents fed through a | | | | carpet weavers who reconstructed the pieces by |
| paper shredder are called chads. | | | | hand. The recovered documents would be later |
| Strip-cut shredders use rotating knives to cut narrow | | | | released by the Iranian regime in a series of books |
| strips as long as the original sheet of paper. These | | | | called "Documents from the US espionage Den". The |
| strips can be reassembled by a determined | | | | US government subsequently improved its shredding |
| investigator, so this type of shredder is the least | | | | techniques, by adding pulverizing, pulping, and chemical |
| secure. It also creates the highest volume of waste. | | | | decomposition. |
| Cross-cut or confetti-cut shredders use two | | | | Modern computer technology considerably speeds up |
| contra-rotating drums to cut rectangular, parallelogram, | | | | the process of reassembling shredded documents. |
| or diamond-shaped shreds. | | | | The strips are scanned on both sides, and then the |
| Particle-cut shredders create tiny square or circular | | | | computer determines how the strips should be put |
| pieces. | | | | together. Robert Johnson of the National Association |
| Disintegrators and granulators repeatedly cut the | | | | for Information Destruction, has stated that there is a |
| paper at random until the particles are small enough to | | | | huge demand for document reconstruction. Several |
| pass through a mesh. | | | | companies offer commercial document reconstruction |
| Hammermills pound the paper through a screen. | | | | services. For maximum security, documents should be |
| Pierce and Tear Rotating blades pierce the paper and | | | | shredded so that the words of the document go |
| then tear it apart. | | | | through the shredder horizontally (i.e. perpendicular to |
| Grinders A rotating shaft with cutting blades grinds the | | | | the blades). Many of the documents in the Enron |
| paper until it is small enough to fall through a screen. | | | | accountancy scandal were fed through the shredder |
| There are numerous standards for the security levels | | | | the wrong way, making them easier to reassemble. |
| of paper shredders, including: | | | | There is an effort underway to recovery the |
| DIN 32757 | | | | shredded archives of the Stasi, the East German |
| Level 1 = 12 mm strips | | | | secret police. There are "millions of shreds of paper |
| Level 2 = 6 mm strips | | | | that panicked Stasi officials threw into garbage bags |
| Level 3 = 2 mm strips (Confidential) | | | | during the regime's final days in the fall of 1989". It took |
| Level 4 = 2 x 15 mm particles (Commercially Sensitive) | | | | three dozen people six years to reconstruct 300 of |
| | | | the 16,000 bags so the German government is looking |
| Level 5 = 0.8 x 12 mm particles (Top Secret or | | | | at modern computerized methods of reconstruction. |
| Classified) | | | | Forensic identification |
| Level 6 = 0.8 x 4 mm particles (Top Secret or | | | | Document shredders display certain device-specific |
| Classified) | | | | characteristics, "fingerprints", like the exact spacing of |
| United States Department of Defense (DoD) | | | | the blades, the degree and pattern of their wear. |
| Top Secret = 0.8 x 11.1 mm (1/32" × 7/16") | | | | These can be reconstructed from the minute |
| United States NSA/CSS 02-01 = 1 × 4 mm | | | | variations of size of the paper strips and the |
| Historically, the US General Services Administration | | | | microscopic marks on their edges, and by comparison |
| (GSA) set paper shredder guidance in the Interim | | | | with the strips produced by known shredders, the |
| Federal Specification FF-S-001169 dated 7/1971 which | | | | individual shredder that was used to destroy a given |
| was superseded by standard A-A-2599 for classified | | | | document may be determined. Jack Brassil, a |
| material which was cancelled in 2/2000. GSA has not | | | | researcher for Hewlett-Packard, works on a project |
| published a new standard since. | | | | for making shredders more easily traceable. (Cf. the |
| There are also alternative shredders that use burning, | | | | forensic identification of typewriters.) |
| chemical decomposition, or composting for disposing of | | | | Injury risk with residential shredders |
| the shreds. | | | | As with any motorized cutting equipment, there is a |
| Shredder trucks | | | | risk of injury. Small residential shredders are becoming |
| A mobile shredding truck is a box truck with an | | | | more and more common. These shredders, although |
| industrial sized paper shredder mounted inside the box, | | | | designed with a narrow opening to the cutting wheels, |
| typically in the front section of the box, closest to the | | | | still pose a danger to pets and small children. Many |
| cab. The box is divided into two sections: the shredding | | | | home shredders can be left in a "stand-by" mode that |
| equipment area, and the payload area for storage of | | | | will start the cutting process when anything is inserted |
| the shredded materials. These trucks have been | | | | into the feed slot. In homes with small children or pets, |
| designed to shred up to 5,000 lbs of paper an hour. | | | | simply keeping the shredder unplugged while not in use |
| Mobile shredding trucks can have a shredded material | | | | can greatly reduce any risk |