Infection Connection

Are wraps getting the rap?
Migrating to rigid container systems

by Susan Cantrell, ELS

Case Medical rigid containers

One of the pressing questions in sterilization today is whether to switch to rigid containers or to continue wrapping. Wraps have been used in one form or another for many years at a relatively nominal cost.

Since money is always tight, why would a facility consider switching? Is it even possible to eliminate wrapping?

If you’re thinking about making the switch, here are a few things to mull over.

According to Paul Bottcher, vice president, Central Sterile Division, Medline Industries Inc., Mundelein, IL, the big issues for the operating room (O.R.) and central supply, with any packaging system, are sterility and ease of use. "Sterilization wrap has a lot of potential for contamination. A container system is more protective and more secure than a sterilization wrap. If there are tears, holes, or moisture in the wrap, sterility is compromised, and that tray must be rejected by the O.R. There’s also a huge cost disadvantage, because money and time have been spent to sterilize that set, and yet it must be reprocessed."

Riley Medical ultrasound l
aparoscopic transducer

Bottcher explained how a rigid container system saves labor costs. "Wrapping a tray takes about 2 minutes. You may have a full-time employee or two who wrap trays all day, seals them with sterilization tape, sterilizes them, and then sends them to the O.R. Central supply wants something very easy for their staff to use. Time is money." Bottcher added, "We’ve taken a lot of manual labor out of loading the instrument set. It literally takes 5 seconds to load a tray and latch the container. Since Medline’s Steriset sterilization containers don’t require disposable plastic locks/arrow or paper filters, the prep time is significantly reduced. You don’t have to worry about potential contamination because it’s a secure system; it’s guaranteed to be sterile until it’s opened."

Going the distance
There are two choices when it comes to rigid, sealed containers: metal or composite plastic polymer. A point often cited in metal’s favor is that, if you drop a metal container, probably the worst that will happen is that it might dent; if you drop a plastic container, you might have to lay out some bucks to repair or replace it.

Bottcher compared composite plastic polymer containers versus metal: "Composite has tiny metal pieces mixed in with plastic. Most container systems on the market are anodized aluminum."

"Anodization," explained Marcia Frieze, chief executive officer, Case Medical, Ridgefield, NJ, "is a coating put on the metal electrolytically to make a material corrosion-resistant. It inhibits the raw material, i.e., aluminum, from reacting with the materials of which the surgical instruments may be made. If you don’t have an anodized product that meets the mil spec, you may get corrosion on the container and the instruments themselves."

V.Mueller Genesis XL

"Anodized aluminum is more durable than a composite," continued Bottcher. "If you drop a metal container, you may get a dent, but if you drop a composite container, you may get a crack. If you have to replace the whole bottom, it could cost another couple of hundred dollars. Most aluminum containers will last 10 to 20 years. Medline looked at introducing a composite container several years ago but, during the validation process, which included accelerated aging tests, we couldn’t get the life of the container to last more than 3 or 4 years. There is a lot of stress put on the containers both in and out of the sterilizers. Composite is just not as durable."

"The materials of construction can affect the useful life of the product," agreed Frieze. "Useful life of the container is important. When you’re buying a reusable container, you want something that is going to last." Case Medical’s SteriTite containers have been heat-treated so that "the issue of dents and dings and corners being damaged and such is very rare with our product," Frieze said. "The only thing besides very rough handling that could hurt the container is caustic or high-alkaline detergents that are not pH-neutral."

"Aluminum rigid containers have a long-standing heritage of providing superb sterility assurance, excellent protection and easier management of surgical instruments," said Barbara Volpe, senior market manager, V. Mueller Products and Services, Cardinal Health. "The first Genesis sterilization container was made back in 1983. They are extremely durable, economical and produce much less waste than sterilzation wrap. Moreover, they do not tear. This can be especially troublesome with today’s heavier sets, which when wrapped, can rip or tear, requiring reprocessing and disrupting the surgical schedule. When it comes to protecting, organizing and ensuring sterility for surgical instruments, rigid aluminum containers are heads above the other sterile packaging options," said Volpe.

Hot stuff
Some argue that metal’s quality of thermoconductivity make aluminum containers the only sensible choice, because metal heats up faster and stays hotter longer than plastic, which may facilitate better drying. Is there really a difference? If there is, is it significant?

"To my knowledge, there’s no published study that compares the materials," stated Bottcher. "Aluminum generates more heat in the sterilizer and cools down quicker than composites, so the dry time for a composite is a little bit longer than for an aluminum container."

Excess moisture and drying time are important issues, because there is great pressure to turn around the sets for reuse as quickly as possible. Fred Finocchiaro, manager of distributor sales and international business development, Riley Medical Inc, Auburn, ME, noted. "Hospitals don’t always have the capital available to invest in additional instrument sets, so they need to turn around more efficiently those sets that may be in high demand but also in short supply."

Frieze highlighted the necessity of good drying ability: "It’s very important that container systems facilitate drying and certainly don’t inhibit drying of the load inside, because a wet load is considered not sterile unless it’s going to be used exclusively for immediate use, and that would be for flash sterilization. There is no such thing as sterile water in a container. Entrapped water is not sterile for any length of time. The advantage with sealed container systems, especially if made of aluminum, is that they provide excellent heat conductivity, so any condensate inside evaporates. That can be a challenge with plastic trays and plastic containers, as well as stainless steel trays, because these materials do not have the thermoconductivity that a sealed aluminum container has."

On the flip side, Finocchiaro believes that, if moisture pools inside a container, the problem likely is unrelated to the material of construction. "Moisture is more likely a result of improper instrument arrangement, improper cycle parameters, or some combination of these factors, which can lead to excess moisture."

Riley Medical manufactures trays for use in sterilization. With the exception of a flash container they make, the trays usually are wrapped, although certain sizes of their trays could be placed inside rigid containers. Because they manufacture both metal and plastic trays, they’re in a position to voice educated opinions on the drying properties of metal versus plastic. Finocchiaro continued: "I would say they function equally as well when used properly. I don’t think one dries significantly better than the other. Metal may have a higher heat-retention value, but if moisture is pooling in the tray, the heat-retention property is not going to make a big difference in effective drying. That being said, we leave the choice up to the customer."

One thing you don’t want to do, Frieze told HPN, is to treat a moisture problem by placing absorbent liners or disposable absorbent materials inside the container. "We do not want to introduce any material into the container that is not critical for the surgery. Absorbing materials could create lint or debris or introduce contaminants like detergent residue. We believe in using just the trays and inserts designed for the intended purpose and not including any other materials that might create a potential for contamination."

Size matters
Many facilities would need to purchase multiple rigid containers in various sizes. Size matters, because of space constraints. "Composite containers are about 25% larger than metal containers," said Bottcher. "They’re wider and taller. They take up more space in a sterilizer and more space on the shelf, so they’re not as efficient."

Volpe explained that the V. Mueller brand Genesis extra long container is longer than the standard container and can accomodate many of the different over-sized and orthopedic sets.

One solution available in using metal containers is the ability to stack. "With a composite container, you can’t stack," said Bottcher. "Our containers can be stacked two or three high in the sterilizer and during storage. This helps the hospitals maximize their space and efficiency."

Frieze, added: "There is internal and external stacking. If the manufacturer has proven efficacy with multiple units stacked, it can be a major cost savings and very useful in terms of efficiency. Case Medical is cleared by the FDA to stack containers three high for steam and ethylene oxide (EtO) and for multiple containers sterilized within the STERRAD system."

Use with different methods
Before you purchase rigid containers, make sure they’ve been validated for the methods of sterilization for which they will be used. "Rigid containers are very versatile and some can be used with multiple sterilization processes including steam, ETO and hydrogen peroxide plasma," said Volpe.

"It’s very important that containers function for their intended purpose. If a container is to be used for gas plasma, for instance, it must be validated for that purpose. Buyer beware," advised Frieze. "Ask for validation data; ask for the FDA 510(k) information and the material specifications. Not everyone can prove their claims."

"Our SteriTite container system is the only universal container system that works for steam, pre-vacuum and gravity, EtO, STERRAD, ozone, and flash sterilization," stated Frieze. "It can be used for terminal sterilization, which means you can put it on the shelf and store it and the container maintains its integrity. That’s very important." She noted that, when wrapped trays sit on a shelf for an extended period of time, sterilization tape could separate, compromising integrity of the wrap, leaving it vulnerable to contamination.

"Most containers can be used with gas and steam," explained Bottcher, "but not with STERRAD. The chamber size of the STERRAD is very small, so you can only fit a couple of containers in there. It’s too much of a torturous path for sterilants to get into and out of a container." These items still must be wrapped. "Typically, that’s only about 5% of a hospital’s load; the steam method would constitute 95% of what a hospital uses for sterilization. Steam is the most efficient method out there. The only reason to use anything other than steam is when you have scopes with heat-sensitive cameras. They need to go through gas or a STERRAD machine. On average, most hospitals can eliminate approximately 85% of the wrap by converting to a container system."

A weighty matter
Container systems can get pretty heavy, particularly those used for sterilizing orthopedic instruments. "When we cleared our container, we did it with a maximum load of 22 lbs, which is somewhat controversial," Frieze said. "We started our business making custom orthopedic trays. We introduced the sterile container system with the idea of being able to sterilize orthopedic sets in a sealed container system that could be transported from place to place, sometimes from one facility to another, sometimes from the loaner location. There’s been a lot of discussion about the weight of some of these trays and instruments. Our goal, as manufacturer, was to leave the decision about weight to the user, to provide a container that, if there was a large, heavy orthopedic instrument such as a 28-lb positioner made of stainless steel that the hospital needed to sterilize for surgery, we could do that."

Most of the interior components of rigid container systems are made of anodized metal or stainless steel. Finocchiaro observed that trays placed inside rigid containers could be made of plastic, which would cut down on weight. "Plastic is a little lighter weight."

The $64,000 question
It always comes down to money. How much money are we talking about to use rigid containers versus wrap? Bottcher figures, over the lifetime of the container, wraps usually cost about three to five times more than what a container would cost. "For instance," he said, "one tray, over a 10-year period, would cost approximately $4,000 to wrap versus most container systems at $1,000 to $1,200 (cost of the container plus disposable filter and lock costs). Medline’s Steriset containers cost even less than other containers because they don’t require filters and locks. Over a 10-year period, the Steriset containers can save a hospital over 80% versus wrap and over 50% versus other containers that require filters and locks. Although we use a 10-year period to perform a typical cost-savings analysis, we have customers who are still using the same containers they bought from us 20 years ago."

Sure, savings may be realized over time, but the initial investment can be cost-prohibitive. Finocchiaro observed that, whereas "Many point to the long term prospect of savings, not everyone is willing to commit thousands of dollars to a single rigid container system that may or may not work for them. An average-size hospital may need 200 to 300 containers in a variety of shapes and sizes. Furthermore, in speaking with clinicians on the subject, many feel it is unrealistic to eliminate completely the need to wrap."

Frieze estimated that it costs about $3 per tray to wrap. "Average price for a container is $550." She cited some of the positives on the cost side: "Rigid containers can hold multiple trays that don’t have to be wrapped. It costs pennies after purchase." Labor costs are saved both by not wrapping and by not having to reprocess wrapped trays that may have holes or tears caused by protruding instruments or just from being pulled off a shelf. "Normally, 10% of all packages that are wrapped for sterilization have to be reprocessed." She also cited rapid turnaround and reduced chance of breakage of instruments as big pluses. "Containers save time and money in the long term," Frieze averred.

Some manufacturers help to make the transition easier financially. Bottcher pointed out: "Medline has creative purchasing options that allow hospitals to convert to our system from wrap with no upfront money or capital needed. They can convert to an easier-to-use and more hygienically secure system at no additional cost."

New guidelines coming
So, what do you think? Are you ready to consider the switch from wraps to rigid containers? If so, do your research. More help is on its way. In 1996, the Association for the Advancement of Medical Instrumentation (AAMI) published "Guidelines for the selection and use of reusable rigid container systems for ethylene oxide sterilization and steam sterilization in health care facilities (ANSI/AAMI ST33:1996)." Frieze said to be on the lookout, because the guidelines are being updated. "The Container Committee at AAMI is in the process of setting manufacturing standards for rigid container systems. Users are becoming involved and becoming more vocal, particularly regarding weight and moisture issues. They are requesting validated products and instructions for use."

A draft of AAMI’s document, "AAMI/CDV-3 ST77—Containment devices for reusable medical device sterilization," is currently available for purchase ($20, members; $25, nonmembers) at