Department of Energy (DOE) OSH Technical Reference

Chapter 10 - Woodworking Machinery

Part 6 - Hazards

Many injuries that occur in woodworking occupations result from employees failing to follow prescribed safe operational practices. These failures arise from worker attitudes, inadequate training, and supervisory failure to enforce safe job procedures. The use of machine guards, environmental controls, good training, and maintenance programs, coupled with supervisory enforcement of protective equipment use and safe job practices can eliminate most mishap-producing factors.

Among the most frequently occurring woodworking accidents are two involving saws: (1) blade cuts or abrasions, (2) kickbacks.

Circular saw operators are often injured when their hands slip from the stock while pushing it into the saw or when they hold their hands too close to the blade while cutting. Kickbacks occur during ripping when a part or all of the work piece is violently thrown back at the operator. Operators should keep their face and body to one side of the saw blade, out of line with a possible kickback.

Overhead swing saws and straight-line pull cutoff saws cause hand injuries because of several operational characteristics. Hands are sometimes cut while the saw blade is coasting or idling and the operator attempts to remove a section of board, or while measuring a board and the saw is still running. Also, the operator may pull the saw against his or her hand or may suffer body cuts from a saw that swings beyond its safe limits. Overhead swing saws, like straight-line pull cutoff saws, require many adjustments to permit their full use. Sometimes these adjustments can create additional hazards for the user.

The principal sources of injury connected with radial saw operations are those common to other power-driven saw operations. They include cutting injuries to the arms and hands caused by the saw blade, by flying wood chips, and by handling materials. When crosscutting, radial saws cut downward and pull the wood away from the operator and against the fence.

Although injuries from band saws are less frequent and less severe than those from circular saws, they are not uncommon. The usual cause of band saw injuries is the user's hands coming into contact with the saw blade. When hand feeding, the operator's hands must come close to the blade. Therefore, it is particularly important that the saw table be well lighted and free from glare. Band saw point of operations cannot be completely covered. However, an adjustable guard, U-shaped and designed to prevent operator contact with the front and sides of the saw blade above the upper blade guides, should be set as close as possible to the work piece.

Jig saws are not normally considered hazardous, but occasionally cause injuries to the fingers and hands. Safe operating procedures require the blade be properly attached and secure, the threshold rest (slotted foot) to be on the stock, the guard to be in an effective position, and the operator to keep his or her hands a safe distance away from the blade.

The principal danger in the use of the wood shaper is that hands and fingers might strike the revolving knives. Therefore, a ring guard is suggested. Severe accidents can also result when broken knifes are thrown by the machine. When a shaper knife breaks or is thrown from the collar, the other knife is usually thrown too, so that four or five pieces of heavy, sharp steel are thrown about the shop with sufficient speed to kill a person. The danger from broken or thrown knifes can be eliminated by using solid cutters that fit over the shaper spindle. Also, there are various types of safety collars that can be used to prevent shaper knifes from flying. However, collars should not be considered substitutes for perfectly balanced and fitted knifes of adequate length.

Hand-feed jointers or surface planers are, second to circular saws, considered the most dangerous woodworking machines. Most of the injuries are caused by hands and fingers contacting the knifes. Many of these accidents occur when narrow lengths of stock are being jointed. The National Safety Council recommends that hold-down push blocks be used whenever the operator joints wood that is narrower than 3 inches (7.5 centimeters). Also, it is mandatory that the unused end of the cutting head be enclosed at all times. A sheet metal telescoping guard is acceptable for this purpose.

Drum, disk, or belt sanding machines should be enclosed by an exhausting dust hood that encloses all portions of the machine except the portion designed for the work feed. Personnel who operate sanders should wear goggles and dust respirators during sanding operations and cleanup. On a belt sanding machine, a guard should be placed at each in-running nip point on both power transmission and feed roll parts. The unused run of the abrasive belt on the operator's side of the machine should be guarded to prevent contact.