WW-03949     Reviewed 2009  

Home Yard Waste Chippers/Shredders:

Safety Is Important!

Copyright ©  2012  Regents of the University of Minnesota. All rights reserved.

With the 1990 prohibition on disposal of yard wastes in landfills in the Twin Cities' metropolitan area and the upcoming 1992 state-wide ban, many people are trying to find a way to manage yard waste.¹

One option is to use chippers/shredders. This method will reduce particle size of yard waste, particularly prunings and woody materials.² These machines usually have a 2.5 to 8.0 horsepower gas engine and cost between $400 and $1,800. Rental rates are usually $30 to $180 per day depending on the type of machine and the season. Most will chip tree limbs up to 2.0 inches to 3.5 inches in diameter. They all use spinning cutters, blades, hammers, or flails to cut the material into smaller pieces. Because these chippers are sharp enough and tough enough to chip wood they have the potential to destroy human fingers, hands, arms, etc. They can also propel solid materials at high speeds. Most are noisy enough to cause loss of hearing, if used for long periods without hearing protection. These machines are very powerful and have the potential to cause personal injury and in extreme cases death, if safety precautions are not followed.

Follow these suggestions to reduce the risk of personal injury:

1. When purchasing or renting a chipper, evaluate it for safety of design and use. Are the belts, shafts, and cutting mechanisms covered? How are wood chips prevented from "kicking back" or "flying out" of the intake feed area? How is the chipped material discharged from the machine? When the machine becomes "jammed" how can it safely be cleaned out? Read consumer and other types of publications for evaluations of different makes of chippers on performance, safety, and maintenance. (3) Ask questions. The best time to consider machine safety is before you buy or rent it. Many machines are heavy and may be difficult to move and set up. If you are unable to follow the safety and operating procedures listed in the owner manual, or physically cannot handle the machine, don't buy one. It may be better to hire someone else to handle your yard wastes for you.
   
   
2. Read, study, understand, and follow all safety procedures and use all safety equipment listed in the owner/operator manual for the chipper you are using. This should include all operation and maintenance procedures as well.
   
   
3. Wear the proper clothing and protective gear when operating this kind of machinery. Clothing should include a long sleeve shirt and pants that are comfortable but not baggy or loose. Remove all jewelry or items of clothing that may become caught or tangled in the operating machinery.
   
   At a minimum, the protective gear package should include:

   a.	Protective eyewear with side shields that meet or exceed American National Standards Institute (ANSI) standard Z87.1. Look for the ANSI label with this standard before you buy. Current prices range from $4.23 to $19.75.
   b.	A hearing protector that is either the ear insert or the ear muff style. In either case you want the device to have an EPA Noise Reduction Rating (NRR) of 20db (loudness reduction) or more. The higher the rating the better. The current price range is from $8.99 to $29.75 for muff-style hearing protectors, and $0.27 to $11.95 for ear insert style hearing protectors, both single use and reusable types.
   c.	Leather work boots, preferably with safety toes that meet ANSI standard Z41.1. Current prices range from $33.92 to $97.00 and up.
   d.	Leather work gloves to provide hand protection from wood slivers and reduce skin abrasions. Current prices range from $2.11 to $9.99 and up.

   
   
   

   This "minimum level" four-piece protective gear package could be purchased for between $40.53 and $156.49 in Minnesota during March of 1990.⁴ If you are figuring the cost of a chipper, you need to include the cost of the personal protective gear that will allow you to operate it safely. Even if you are only renting a machine for a day or less you will need this type of protective gear for your own personal safety. Other optional gear might include a logger's safety helmet (a helmet with attached screen face shield and muff-style hearing protector attached into one unit), $27.99 to $49.00 and up; dust mask, $0.40 to $1.50; and chainsaw chaps, $47.99 to $67.50 and up. In every case you need to choose specific protective gear that fits you and that you are comfortable wearing. A piece of protective gear that is so uncomfortable that it is not used, cannot provide you with any protection!
   

4. Keep children, observers, and pets well away from the area where you are operating the chipper.
   
5. A chipping team of two people, working together, provides an added measure of safety and quicker access to help should an accident occur. The second person's primary job is to keep children and others away. This person needs to wear at least the minimum recommended protective gear.
   
6. Put only approved materials into the machine at recommended feed rates. Materials such as metal or rocks can be accelerated to speeds in excess of 140 m.p.h. creating a danger for the operator and bystanders.
   
7. Use of a written pre-start-up safety check list, and a post-shutdown safety check list can help to assure that you are following all of the necessary safety procedures.

¹Grass clippings in most cases should be left on the lawn where they were grown. This reduces the need for additional nitrogen fertilizer and conserves water. It is a direct way to "recycle" organic material to the soil. For more information see: Lawn Clipping Management by Phil S. Allen and Donald B. White, Minnesota Extension Service, FO-3915, 1990, St. Paul, MN.

²If you intend to compost fall tree leaves you will usually not want to go to the time and expense of shredding the leaves, because you will lose free air space within a static pile system. If you are using a forced air compost system, shredding the leaves may be advantageous. If you are having your leaves disposed of by a garbage hauler, shredding the leaves will reduce the volume of leaves substantially. Reduced volume may reduce your yard waste collection/disposal bill. For more information see: Composting and Mulching: A Guide to Managing Organic Yard Wastes by Carl J. Rosen, et al., Minnesota Extension Service, FO-3296, 1990, St. Paul, MN.

³Check the magazine indexes at your library for recent articles on yard waste shredders, wood chippers, and lawn and yard equipment.

⁴These price ranges are meant only as a general guide.

About the Authors:

Thomas R. Halbach is an Assistant State Specialist, Water Quality and Waste Management, Minnesota Extension Service, Department of Soil Science; Tom Brennan is an Extension Safety Specialist, Minnesota Extension Service, Department of Agricultural Engineering; and D. Walter Halbach is a Research Fellow, Department of Agricultural and Applied Economics. All are with the University of Minnesota.

Produced by Communication and Educational Technology Services, University of Minnesota Extension.

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