Don't Stumble Over Safety

Larry Trojak

`Safety hazards are an issue in any workplace, but employees at material recovery facilities (MRF) are constantly confronted with special risks. Left unchecked, MRFs could be a veritable accident waiting to happen.

Processing equipment, peripheral equipment, adjacent areas and the waste stream itself all present injury potential and in more severe cases, disease and death.

Fortunately for such employees, management is striving to take a proactive role in ensuring worker safety. Whether driven by a genuine desire to protect workers or by the more fiscal goal of minimizing worker liability issues and costs, an intricate system of safeguards exists to ensure that today's MRF environment re-mains as safe as possible.

A look at any five MRFs would reveal five different safety approaches within each facility. Much of this variance is reflective of the types of material processed through the site, the site itself, available equipment and management practice.

For the Medina County, Ohio, Central Processing Facility, operated by Norton Environmental, the emphasis starts with new employee safety orientations, adheres strictly to established safety guidelines in both operation and equipment procurement and comes full-circle with periodic worker safety updates.

That emphasis has paid off in a number of ways, according to Norton's Louis Perez. "Ours is a progressive management style that encourages workers to be more knowledgeable which improves their ability to sort effectively and therefore increase percentages," he said. "We do this through a good deal of video training that shows our view of the safe way to work within the MRF: what materials to look for, the correct procedure for dealing with heavy material and how to identify hazardous material."

In addition, Perez said periodic refresher training sessions help. "This has paid off in our recoverable rate - 15 percent on our percentage of recoverable recyclable commodities," he reported.

Early Identification Medina County's adherence to strict safety guidelines begins on the tipping floor.

"In my years of working with MRFs throughout the northeast, I've seen pretty much everything come through, including knives, guns and ammunition," Perez said. "Unlike most MRFs, we use a segmented approach to incoming material inspection. We first look at material on the tipping floor and try to identify potentially hazardous materials - such as a propane tank or a box whose contents are in question.

"Once material is identified as questionable, we use mechanical means to sort it out. It is imperative that we remove the material before it gets to the sorting room where it could pose a problem to the sorters. There is a similar checkpoint on the infeed conveyor."

Perez said all of the bags processed at the Medina County facility are opened in an enclosed, reinforced trommel, which eliminates the risk of injuries caused by manual bag opening.

Equipment Safety Four years ago, the American National Standards Institute (ANSI), New York, N.Y., and an independent committee began to research and write a set of uniform standards for MRF operations (see sidebar on page 39).

The result was the ANSI Z245 report "Facilities for the Processing of Commingled Recyclable Materials: Safety Requirements."

"ANSI is an independent agency and, unlike OSHA regulations, the standards are voluntary," said Sidney Wildes, president of International Press & Shear Corp-oration, Baxley, Ga., one of the original committee members. "But although adherence is voluntary, it is very much to everyone's benefit to accept them because, in many cases, there are no others. Doing so makes good sense from both a safety and basic business standpoint."

Much of the emphasis on safety within the MRF is dependent upon the design and operation of the equipment used to process the waste stream. Equipment manufacturers regularly update designs to incorporate safety features, either as a standard element or to accommodate particular customer needs.

Wildes, who has been involved in compiling a similar set of guidelines to cover safety requirements geared specifically to balers, said he strives to design a safety-based baler line. Calling safety a "big concern from the initial design phase," he notes several features that aid in baler safety such as a startup alarm to indicate when the baler is in operation and a host of emergency stops located on various parts of the machine.

"The bale door keeps the material contained while it is being put under pressure; the door opens only when the baling process is complete and the bale is being ejected," he said.

These baler units also feature an oil temperature and level transducer which is monitored regularly by the computer. If an oil overheats or a low level situation occurs, the computer shuts down the unit and issues an alarm. The machine can only be restarted when the alarm resets.

Another feature to look for when considering a baler purchase is a through-the-panel disconnect switch that can be locked in the "off" position and tagged in accordance with the Occupational Safety and Health Association's (OSHA) "lockout/tagout" regulations.

Doing so ensures that once a unit is locked in the 'off' position, power cannot be turned on to that machine, Wildes said.

Safety In Shredding Reducing material size and volume often is the job of a shredder, and MRF operations - particularly those with a market such as refuse derived fuel (RDF) - have incorporated them readily into their designs.

Over the years, product modifications have been made to meet the safety needs of these customers, according to Grand Prairie, Texas-based Saturn Shredder's Damon Dedo, who says that the use of a slow speed shredder is itself an inherent safety benefit.

"In the past, MRFs and RDF facilities used to rely almost exclusively on high speed hammermill-type shredders and explosions were commonplace," he said. "We had one incident in Florida in which several sticks of dynamite were intercepted just before processing. In a hammermill, that could have been a serious situation. The slow speed of rotary, shear type shredders is definitely a factor in reducing the risk of explosions."

Even with that risk reduced, precautions are taken to ensure safety. At the Medina County operation, engineers designed a fully-enclosed feed hopper with a small exit port to contain the risk of flying debris caused in the unlikely event of an explosion.

"About 35 percent of Medina County's total daily waste stream - about 140 tons - is fed into a shredder in preparation for use as RDF," said Dedo.

Other non-standard safety features on shredders include side wall eject systems: In the event the shredder encounters an unshreddable material, users are no longer required to shut down the system and reach into the hopper to remove it. With the touch of a switch, the material automatically can be ejected from the shredder's side.

In applications that process bulky waste rather than separate it, a push ram modification feature is optional. Bulky material that, by nature of its shape and/or mass cannot be drawn into the counter-rotating cutters, now can be forced into the cutter throat using the ram option and shredded. This eliminates the need for the material's manual removal and, thus, reduces the worker's risk.

"As the role of the MRF continues to evolve, much will change with regard to new equipment use and process modification," said Dedo. "New demands will be placed on workers and new safety concerns will become evident. All parties involved in the material recovery process should continue to see safety as a critical issue.

"No one gains by relaxing the emphasis upon this issue."

ANSI Z245, compiled by the American National Standards Institute Inc., New York, N.Y., offers the following safety guidelines:

6.3.4.3.2 Prepared aerosol cans - Aerosol cans are considered to have been prepared for processing if they have been emptied of all residual propellants and opened to the atmosphere. Additional Clean Air Act, OSHA and RCRA rules apply to the processing of aerosol cans and off gases.

7.3.5.3 Emergency stop feature - All sorting stations shall have an emergency stop control located within 2.75 meters (3 feet) of each employee's normal working position, which shall control at a minimum: the conveyor, upstream feed and any system component immediately downstream from the sorting station, except for sorting on the floor to a sub-conveyor with a 3-foot transition to the next level.

7.1.7.12 Prohibition from riding on conveyors - Employees shall not ride on any conveyor in a facility constructed subsequent to the effective date of this standard. In facilities which existed prior to the effective date of this standard, employees shall ride only on those conveyors which are specially designed for the purpose as permitted by their employer and the facility owner.

7.3.5.5 Flooring (sorting station) - Flooring shall be constructed of a slip resistant material that can be readily cleaned of the types of wastes or recyclable materials which are processed in the facility.

8.3.3.2 Basic hazard communications (Hazcom) - Employers are required to provide information to their employees about the hazardous chemicals or materials to which they are exposed by means of a Hazcom Program, labels and other forms of warning, material safety data sheets, information and training.