The US Consumer Product Safety Commission (CPSC) carried out an nvestigation of reported finger injuries, including amputations, and the characteristics of domestic paper shredders that might have contributed to those injuries. The National Electronics Injury Surveillance System (NIESS) database collected 23 reported finger injuries attributable to domestic paper shredders. The ages of the victims ranged from 14 months upwards. Of the 23 reported finger injuries caused by a domestic paper shredder mechanism, fifteen involved children aged 5 years and under. However, finger injuries from domestic paper shredders have been reported in victims of 20 years old and even 65 years old. This report was published in December 2004.

The most severe injuries, amputations, involved children. Injury occurred even when a child was feeding paper into a shredder under adult supervision but did not release the paper in time to prevent their fingers from entering the shredder opening. As the paper shredder continued to pull the paper into the shredder opening, it also pulled in the children's fingers.

Since most paper shredders have auto start features, a child can be at risk even when an adult is present. A child may insert a piece of paper into the shredder opening and activate the shredder mechanism, allowing it to pull the paper (and possibly the child's fingers) into the shredder. Children are not conscious of hazards to themselves and may not let go of the paper as it is being pulled in.

Paper shredders can pose a risk of finger injury to children as young as 15 months because of their small finger size. With no force applied, a child's finger would be unlikely to penetrate the shredder opening since their finger diameter is typically larger than a paper shredder opening. However, depending on the design of the shredder, the shredder opening may enlarge as the shredder pulls in the paper and child's fingers. The height of a 15-month-old can be more than twice the height of a domestic paper shredder, putting them within easy reach of the paper shredder opening.

The International standard that applies to paper shredders is IEC (International Electrotechnical Commission). The methods of testing the safety of shredders has in the past involved the use of a probe which was meant to represent the dimensions of the fingers of a twelve year old child. The probe was not designed or intended to determine the risk of injury to younger children.

The shredders that were tested prior to the report produced by the U.S. Consumer Product Safety Commission were on sale for between $20 and $70. The design characteristics of domestic paper shredders that may contribute to the danger to toddlers include the width of the opening or "throat", the stiffness of the material from which the shredder "throat" is constructed, the distance from the opening to the cutting mechanism and the pulling power of the shredding mechanism. In general, the crosscut shredders tested allowed larger diameter probes to pass through the shredder "throat" than the strip cuts shredders that were tested. Since crosscut shredders require more power to shred paper the motors were consistently more powerful and this would pull a child's fingers in more easily. None of the shredders tested had a separate On/Off switch separate from the Auto / Forward / Reverse functions. Critical safety information was not universally displayed on all models and some had no warnings at all at the shredder "throat". Some shredders did not show contrasting colours for the switches which may be a safety concern if it should become necessary to turn off a shredder or put it into reverse in an emergency.

Some of the observations given by the U.S.CPSC can be summarised as follows:-

Crosscut shredders allowed thicker rigid rods to enter the shredder throat than did strip cut shredders

Cross cut shredders were more powerful and thus more likely to pull in a child's fingers

Crosscut shredders allowed the smallest compressible probe to enter the shredder throat

Crosscut shredders allowed larger compressible probes to enter the shredder throat

Only some shredders had an OFF position on the function switch

No shredder tested had a separate ON/OFF switch separate from the Auto/Forward/Reverse functions

Not all shredders carried the same hazard markings at the shredder "throat"

Some shredders did not have contrasting colours for the hazard markings

Some shredders did not have contrasting colours for the function markings

The CPSC came to some conclusions on the samples tested, but pointed out that this was not a statistical sampling or a sample of all types of paper shredders:-

Paper shredders pose the greatest threat of finger injuries to children between the ages of 15 months and 2 years (based on incident data)

The level of risk depends on the design of the shredder opening or "throat"

Current testing (as at December 2004) did not relate to hazards involving small children

The design of the shredder "throat" determines the amount of force required to insert a probe into the shredder. These factors include width of opening, stiffness of opening, distance from opening to shredder mechanism, compressibility of fingers and the pulling force of the shredder involved.

The researchers called for domestic paper shredder manufacturers to redesign the shredders to improve safety aspects and for them to carry clear warnings directly on the machines. The authors also recommended that paediatricians ask parents whether they have a paper shredder in the home and if so to advise them to leave it unplugged and out of reach and to never allow a child to use the shredder, even when an adult is present.

David Jenkins, of the Royal Society for the Prevention of Accidents in the UK was recently quoted by Sarah Womack, of The Daily Telegraph as saying "I am not aware of a problem in this country yet but with the increasing popularity of paper shredders - and if similar designs are available here as in America - accidents are likely to happen".