Metal products can be protected from corrosion during transit and storage by wrapping them in polyethylene film that contains volatile corrosion inhibitors, or VCIs. The VCIs escape from the film, and deposit on the product surface. Anticorrosion films see use in almost every industry including automotive, electrical and electronics, machine manufacturing, even more so in the military. Globalization has driven demand upward as more goods travel further from their places of manufacture. One critic, and rival distributor, claims VCIs are hazardous.
Making a case?
The danger, says Randy Dutton, VP and part owner of barrier film distributor FPM Inc., based in Flat Rock, MI, is that those VCI vapors in the film contain hazardous chemicals that may come into contact with people handling the products.
For decades, VCIs were based on nitrites, in concentrations now known to be carcinogenic. VCI suppliers say they no longer use nitrites. Dutton claims that many simply have switched to poorly researched variations of similarly hazardous chemicals in hopes of staying ahead of overworked regulatory organizations, or even mislead by not naming some chemicals on their products'' material safety data sheets (MSDS).
FPM is the leading distributor of an alternative corrosion-protection film, which incorporates Intercept barrier technology, developed by Bell Laboratories. The technology is marketed by EMI (Engineered Materials Inc.; Buffalo Grove, IL), which contracts film extrusion. Intercept barrier films have copper reacted into their polymer structure to work as a moisture barrier and also to neutralize corrosive gases.
This month Dutton spoke to the VCI technical working group of the NACE (National Assn. of Corrosion Engineers) on what he says are false claims used in VCI marketing.
Dutton provided MP with a long list of documents he has sent to various U.S. regulatory agencies regarding these claims. And he''s also built a website, www.vciproblems.com, to present his evidence. The target of most of Dutton''s wrath is Cortec Corp. (St. Paul, MN), one of the leaders in processing VCI films.
Out of context
At Cortec, integrated solutions manager Bob Boyle says his firm welcomes competition—"It keeps us on our toes"—but is seeing increasingly hostile actions from non-VCI competitors and barrier-film processors.
"Even though barrier-film replacement is a small portion of what we do, we have been targeted by Mr. Dutton. We assume this is because [FPM''s] main potential market is currently and effectively supplied by VCI manufacturers," he says.
Compared to barrier films, Boyle says, "VCI packaging films will typically provide better corrosion protection at a lower material cost and a much more effective application method (as heat shrinking or vacuum sealing is not required) allowing parts to be shipped much faster."
Boyle says non-VCI competitors are taking data out of context to paint a false picture of the threat that VCIs pose. One distributor of Intercept material sent Cortec''s customers information that it later had to retract after Cortec sued, Boyle claims.
Dutton says his campaign against VCIs goes beyond attempting to displace a well-entrenched competitor. His experience with VCI films dates to his military experience, when he served as the Material Officer at Long Beach Naval Shipyard in California.
"In the 1990s I was an advocate and user of VCIs in what was then probably the largest VCI wrapping project ever performed—wrapping 10 MD-11 fuselages with VCI shrinkfilm," he recalls.
But his crew complained of the strong, unpleasant smell, and Dutton became convinced of the materials'' dangers as he learned more about them. He recalls that the extrusion company supplying film for the fuselage project refused to process a second batch due to the formation of noxious fumes in its facility. He says the assault on VCIs is also personal because, at the shipyard, he oversaw employees afflicted with asbestos-related diseases; he worries that VCIs could also have as-yet-unrecognized, long-term negative health effects.
Crayex Corp. (Piqua, OH), the company who supplied the film, could not confirm Dutton''s recollection. The processor has extruded VCI films since 1990, and Don Trumball, Crayex plant manager, says, "As in most blown-film plants, general mechanical ventilation is adequate for employee comfort, safety, and health; this is no different with the VCI films we produce." Dutton responds that the man most knowledgeable about the situation now is retired from Crayex and, when contacted by FPM, refused to comment.
Dutton admits that Intercept often costs more than VCI impregnated film but says its long-term anticorrosion performance makes for lower total costs, and repeats that VCIs are hazardous anyway.
In a recent presentation "Evaluation of Barrier Materials for Military Packaging," Samir Sarker, from the packaging and support division at Picatinny (Arsenal, NJ) showed Intercept beating VCI films in metal corrosion prevention, and surpassing the Army''s standards. He noted Intercept costs $350 for a 3-ft-by-600-ft roll, just over double some competing materials, but estimates Intercept''s total cost is lower due to the longer protection it offers to packaged goods.
Thrust and parry
Boyle says VCI films, as manufactured today, are perfectly safe when basic instructions are followed, and refutes Dutton''s claims regarding misleading data sheets.
"All MSDSs provided by Cortec Corp. reflect the recommended protective equipment for each specific product," he states. During production, employees wear respiratory gear when handling VCI in powder form, but once mixed into a masterbatch, gloves are sufficient.
Dutton provided MP with test results showing nitrites in Cortec films, but Boyle says the firm does not use sodium nitrite as a corrosion inhibitor. Nitrogen compounds (including sodium nitrite) are used as a processing agent so tests may reveal very minimal nitrite content in Cortec films, Boyle explains.
Frank Kroekel, CEO of COMPtrade Technologies GmbH (Eisenach, Germany), which markets FPM''s films to potential users in Europe and Africa, says that in Germany, processors using Intercept technology are seeing a rush of customers who previously used VCI films.
"I''ve never seen so much client interest," he says, citing firms such as BMW and other carmakers. He traces the increase to a new German technical regulation, TRGS 615, that is based on the results of a test, "Studies of N-nitrosamines in anticorrosion films and papers," published in the May 2003 issue of Gefahrstoffe (Hazardous Materials).
The study discovered volatile nitrosamines in 13 of 40 VCI impregnated films and papers tested, and only 17 of the 40 contained no trace of nitrosamines. Seven exceeded levels requiring them to be labeled as containing carcinogens. The study''s authors recommend use of products that do not cause nitrosamines to form.
The U.S. Army''s take
The military is a huge user of VCI films and one Dutton aggressively pursues. At the U.S. Army Materiel Command Logistics Support Activity Packaging, Storage and Containerization Center (PSCC) Laboratory in Tobyhanna, PA, industrial engineer Charlotte Lent is wary of the subject but says, "There are instances where (VCIs) are dangerous, but not all VCIs are dangerous any more. . . .It''s not really much of an issue."
Lent says Intercept and other barrier films must beat VCI films on merit alone.
Matthew Defosse firstname.lastname@example.org