While your company documents may not be a matter of national security, many firms use paper shredders to ensure that sensitive documents don't fall into the hands of their competitors.

Although dumpster diving may seem the stuff of a bad spy novel, what's noteworthy is that the courts have ruled that items found in the trash are in the public domain. This means that picking through trash, however unsavory, is legal.

This guide is designed to give you the facts you need to choose and evaluate a paper shredder for your business. The various sections are listed in the box above. You can choose to read this guide from beginning to end, or jump directly to a section of interest.

How a Paper Shredder Works

Paper shredders consist of a pair of rotating cutting blades, a paper comber, and a motor that drives this assembly. Paper is fed between the two intermeshing blades and is split into many small pieces by the force of the blades.

The produced shreds are held in one of a variety of containers. Low-end shredders are simply draped over the edge of or straddle an office wastebasket. Slightly more expensive ones come equipped with their own wastebasket. Most office grade shredders typically come with an enclosed cabinet with wheels to make it easier to roll about the office. Finally, there are some shredders that come with a stand that can hold a plastic bag.

Types of Shredders

Shredders vary according to how they are used and the types of materials that will be destroyed.

Personal Shredders
Are designed for infrequent use by one person. These models typically require a strict diet of paper in order to avoid jams and breakdowns. Personal models take 2-8 sheets at one pass.

Commercial Grade Shredders
Are much larger units, designed to handle many more documents. These models are equipped with higher power motors that allow them to chew through paper for longer periods of time. Office grade units can usually be placed in a hallway or mail room. Due to the noise and size, heavy duty models are most often found in a warehouse.

Purchasing Considerations
The three main considerations when buying a shredder are the types of materials you will be shredding, the volume of shredding the machine will be handling, and the security level your company needs to ensure privacy.

Materials
Most shredders are designed to handle paper, with the occasional paper clip or staple thrown in. If you plan to shred computer printouts, you will want to find a shredder with a throat (or opening) wide enough to allow the paper to be fed directly into the machine. There are also shredders that can handle crumpled paper through a hopper design.

Some shredders can handle more than just paper. Objects like credit cards, videocassettes and computer diskettes can be munched by these specialty shredders.

Shred Volume
The volume of paper the shredder will be handling is a second major purchase consideration. Key characteristics to consider include the unit's paper capacity, or how much paper can be fed at once, as well as its shredding speed. Since shredders are not designed to operate at its maximum paper capacity at all times, you will want to look for a shredder than can handle about 25% more pages than you need to shred at a time to avoid early breakdown.

Shred Type
In terms of security, most businesses find a basic strip-cut shredder adequate for meeting their security needs. These machines cut paper into ribbon-like strips, varying in width from 1/12" to 1". Generally, you will want a shredder that cuts paper into a minimum 1/4" strip.

However, for more confidential documents, cross cut shredders are preferred. These machines cut both lengthwise and widthwise, turning a page into 500-800 confetti-like pieces of paper. For the highest security requirements (such as military contractors), there are high security particle cut models that can shred a page into more than 1,500 pieces.

Maintenance Concerns

Your basic commercial office shredder is designed to last seven to ten years. Ongoing maintenance of these units typically includes oiling the cutting assembly to reduce friction, removing dust that builds up in the blades, and replacing bags as they fill. It is also important that the shredder not be continually used at its maximum paper capacity.

Personal models are really not designed to be repaired. If a model breaks down while under warranty, the manufacturer will usually send a replacement model rather than pick it up for repair. To minimize the likelihood of breakdown, it's important that the shredder not be used for more than 10-15 minutes at a time and that the recommended paper capacity not be exceeded.

Special Tips

Dealer or Superstore?
Office equipment dealers that specialize in the sale of shredders provide the best selection of models and are the only choice for office-grade units. However, if you are simply looking for a shredder for infrequent personal use, an office superstore's offerings should be fine.

Time to Take out the Trash
A bin full indicator, which alerts you when a bag is full of shreds, can be a very useful feature, particularly for shredders that are housed in a cabinet. Overflowing bags of shredded paper are one of the most common causes of paper jams.

It's Better to be Safe Than Sorry
Watch out for dangling objects, like neckties, that can accidentally feed into a shredder when it is in use. For safety reasons, the on/off switch should be in easy reach of the user. Also, if children are in the office, look for one where fingers can't reach the blades.

Lowering the Cost of Consumables
Replacement bags can be purchased from the shredder manufacturer. However this can be very costly, with prices often more than $0.50 per bag. A better alternative is to contact a plastic bag manufacturer and order bags with similar dimensions.