Exploring the ROI of Safety
Implementing a vacuum conveying system for transport of bulk dry materials can increase safety and profitability.
Workplace injuries in any organization take a bite out of profits. A wealth of data, statistics and surveys is available from scores of organizations regarding occupational illness and injuries. The statistics regarding the number of injuries and illnesses that occur on the job—and purported annual costs of $250 billion—are astronomical and difficult to digest at an organizational level. As a result, they can dilute the significance of injury costs to a single organization.
To bring these costs closer to an organizational level, it is necessary to first identify the most common injuries and illnesses in the manufacturing arena. In the goods-producing industry, which accounts for 35% of all occupational illness and injury cases, “manual materials handling is the principal source of compensable injuries,” according to the Occupational Safety and Health Administration (OSHA).
When practical, designing the hazards out of the process through engineering is the best method for reducing them. While four out of five manual materials handling injuries affect the back (e.g., lifting, repetitive motion, slips and falls), additional safety hazards, such as a poor respiratory environment and fugitive dust problems, can occur when manually transporting bulk dry materials. Such hazards can be effectively eliminated when pneumatic conveying systems are present.
Pneumatic conveyors use vacuum suction to gently and quickly move materials from point to point with nothing in the way to impede efficiency. Used to convey, batch, and weigh dry materials from fine powders to plastic pellets and caps, pneumatic conveyors comprise five basic pieces of equipment that come together to work as one: a pick-up point, convey tubing, a vacuum receiver, a vacuum producer and a control module.
From simple options that semi-automate a process to more sophisticated systems that offer complete automation, pneumatic conveying systems can improve plant safety. While no single equation can determine the return on investment (ROI) for all organizations engineering out a safety hazard, data does exist to help determine how pneumatic conveyors contribute to the bottom line in terms of reduced or eliminated hazards and gains in productivity.
OSHA’s $afety Pays ($P) worksheet, which calculates the costs associated with specific injuries and includes a dollar amount of additional sales (and increased production) needed to cover those costs, can help managers to quantify the benefits of reducing or eliminating hazards when implementing a pneumatic conveying system. One of the most effective methods to justify the costs of ergonomic improvements is through production enhancements. Even shaving seconds from a single process can have a huge impact. An example illustrated in the American Society of Safety Engineers’ (ASSE), “ROI of Ergonomic Improvements: Demonstrating Value to the Business,” validates how shaving 3.2 seconds from a task can reduce direct labor costs by $29,000 per year.
It is not unusual for organizations to seek out pneumatic conveying solutions for the express purpose of eradicating ergonomic hazards. A common dilemma in the industrial world is the manual transport of materials to raised platforms, where ingredients are dumped into hoppers. This action represents not only ergonomic hazards, but also a fall hazard. Although the majority of organizations seeking to eliminate this type of hazard have yet to experience a fall event, automated solutions should be implemented to safeguard workers.
It is not unusual for organizations to seek out pneumatic conveying solutions for the express purpose of eradicating ergonomic hazards.
In one example, when increased demand turned up the notch on production for a particular product, a chemical manufacturer’s primary goal was to eradicate an ergonomic issue by removing the need for workers to dump 20-40 drums, weighing up to 225 lbs each and containing powder chemicals, from a raised platform. Although the company hadn’t had any injuries with that process, its policy was to wipe out any potential.
The job required a single operator, but the organization staffed it with two people to reduce the potential for injuries. Before considering a pneumatic conveying system, the company tried a bucket elevator. However, that method created a lot of dust in the air and still presented an over-exertion hazard when the product needed to be dumped into the elevator. The company also considered a hoist system, but that would have required operators to do some drum handling, which would have slowed the process significantly.
The size of a pneumatic conveying system depends on the desired speed at which product is transferred from one place to another, as well as the distance between two transfer points. Because the company wanted to eliminate an ergonomic issue and timing wasn’t an issue, it chose to use a smaller conveying system.
To move several hundred pounds of material in 30 minutes, a non-mechanical vacuum conveying system was used to transfer the clay-like material up a level into a volumetric feeder. Another system was also added to a separate line that pulled granular material from awkwardly shaped drums (weighing over 200 lbs each) into a liquid mixing tank.
Although the time to transfer the products stayed relatively the same with the new units, the job went from requiring two people to a single operator and eliminated a hazard. The company wasn’t looking to reduce its staff, but they did save some money, and the unit paid for itself in the first year of use.
Elevated falls are less frequent but more severe than same-level falls in the workplace. In 2011, falls, slips and trips claimed the lives of 666 workers, and one in four resulted from a fall of less than 10 ft. The manufacturing industry experienced 47 of the fall fatalities in 2011. OSHA’s $P worksheet does not include cost data for fatalities, but a 2003 mean estimate of direct costs for a single fatality in the workplace was approximately $900,000.
Direct costs are budgeted costs, or insured costs. Indirect costs are those that are not budgeted (not insured) and thus eat away at profits. Indirect costs are estimated to be anywhere from two to 20 times the direct cost, and include training replacement employees, accident investigation, implementation of corrective measures, lost productivity, fines and penalties, repairs, and any other costs not covered by insurance, including loss of employee morale.
Fall fatalities demonstrate a worst-case scenario in the workplace and have a severe impact on employee morale, and high indirect costs that are conservative at $1 million. Most commonly, falls, trips and slips result in back injury or some other musculoskeletal disorder (MSD); however, MSDs from those hazards are often calculated separately. MSDs include any injury, damage or disorder of the joints or other tissues in the upper/lower limbs or the back.
In the manufacturing arena, four out of five materials handling injuries affect the back and require a median of 10 days for workers to recuperate. Using the $afety Pays worksheet and calculating with a 5% profit margin, a strain has indirect costs in excess of $33,000 and requires an additional $672,122 in sales to recoup those costs. Any time organizations can eliminate the possibility of back injuries, injury costs should be taken into consideration when determining ROI.
In another example, while working on a major efficiency project that culminated in the building of new rooms for a blending area, a tea manufacturer wanted to also cut down the amount of lifting that the operators were doing manually in the production department. Previously, the operators were manually weighing individual 100-lb batches into barrels, using forklifts to transfer them to the top level and then dumping them into hoppers by hand.
One of the biggest concerns for the tea manufacturer was the breakdown of the materials themselves. Pneumatic conveying is a gentle way to move product, however; once that was proven to the manufacturer, the system was designed to automate the process.
Now, rather than operators using forklifts to bring barrels up to the mezzanine level and manually scooping materials into the hopper, operators insert a wand into the barrels, and product is pneumatically transferred from the wand to the blenders, eliminating forklift traffic and strain to the workers’ backs. In addition to eliminating ergonomic issues and potential costs associated with injury, the company had a 20% increase in productivity.
Pneumatic conveying systems are fully enclosed to protect materials from air, dirt and waste. Because product does not escape from a pneumatic conveying system, particulates that can endanger workers’ respiratory health or settle on equipment and surfaces—thereby posing an explosion hazard—are prevented from entering the environment. Any time a pneumatic conveying system is used, costs associated with housekeeping diminish, along with the potential for a dust explosion. The cost of employing even the most sophisticated pneumatic conveying system would undoubtedly be far less than that of a dust explosion.
Since the inherent nature of the pneumatic system prevents loose powder from becoming airborne, it makes for a cleaner and safer environment all around, and a greater number of organizations are looking at safety reasons for engaging a pneumatic conveying systems. Several years ago, a cable manufacturer faced a major materials handling problem: two of the 14 ingredients used in its process were toxic. The ingredients were received in powder form in 50-lb bags, which were opened on the production floor, hatched on platform scales and manually dumped into a mixer or blender. Despite extensive use of exhaust ducting and respiratory protection for the workers in the area, engineers were still concerned with the impact of toxic contamination on the environment and the threat of not meeting OSHA regulatory standards.
According the $P worksheet, indirect costs for a single dust disease are around $25,000, with an additional $509,000 needed in sales to recoup the cost. The worksheet also lists additional conditions and illnesses that can be caused by exposure to dusty environments, such as dermatitis. A single injury for dermatitis can result in indirect costs around $10,000 with over $200,000 of additional sales to make up for those costs.
The cable company eliminated the need to dump 50-lb bags of toxic material into a mixer manually by converting to a monorail-mounted hoist. The device lifts and positions semi-bulk bags to an unloader, which forms a dust-tight seal against the ring on the discharge opening. Agitator pads and an auger under the storage bin help deliver material into a weigh hopper on the floor below at a controlled rate. The material is then conveyed to a blender on an upper floor.
The entire flow path is enclosed, resulting in a safer environment. Because of the bulk packaging, the cost per pound of materials is lower. In addition, handling costs in receiving, storing and discharging the materials are substantially lower.
Manual materials handling is the leading source of compensable injuries in the manufacturing sector. Many of those injuries could be avoided by employing a pneumatic conveying system, often for less than combined direct and indirect costs associated with those injuries. Nearly 100% of the time, solving a workplace hazard with a pneumatic conveyor system increases profit through production efficiencies.