Due to differences in individual body chemistry, no single primer is going to work best for every client. So study your options: methacrylic acid primers, “non-acid” primers, and a new primer-less acrylic system.
Without primer, there would be no acrylic nails. And even with the recent introduction of primer-less monomers from companies such as Creative Nail Design and Supply Source, primer will remain an integral step in most acrylic systems for the foreseeable future.
Even Creative Nail Design's chemist Doug Schoon, who developed the company's primer-less monomer Retention-, admits it is not yet the perfect product for everyone. "I would be surprised if our next monomer needs a primer. But primer won't go away."
It's certainly an understatement to simply say that primer improves the bond between acrylic and the natural nail plate. Without it, the acrylic would just sit on top of the nail. "When monomers link together to form polymers, each individual monomer joins with the next monomer to form long chains," Schoon explains. "The most powerful bond molecules can make is called a covalent bond. Then there are somewhat weaker — though still strong — bonds called hydrogen bonds."
Acrylic molecules can't bond at all with the nail plate because the proteins in the nail plate share no attraction with the acrylic; hence the need for a "glue" to bond the two together. Enter primer, which bonds at one end with proteins in the nail plate and at the other end with the acrylic molecules. Some people, in feet, liken primer to double-sided tape because of how it works to bond two dissimilar surfaces.
"Essentially, one end of the primer molecule is attracted to some of the amino groups in the protein of the nail and forms hydrogen bonds with them," says Larry Steffier, vice president of chemical operations for Cherry Hill, N.J.-based Keystone Industries. "The other end of the primer molecule is attracted to the acrylic molecule and forms a very strong covalent bond with it."
The cyanoacrylates used in wrap systems, on the other hand, do share an attraction with nail plate proteins and form a strong hydrogen bond directly with the nail plate. Hence, the absence of primers in wrap systems.
Search for the Better Mousetrap
Along with acrylic monomers and powders, the nail industry borrowed primer, too, from the dental industry. Methacrylic acid (a chemical used in making plastics and resins) primers have dominated in the nail industry because, quite simply, they work. "There may be some primers that work better on some people, but taken over the course of 100,000 clients methacrylic acid primers work very well on the largest percentage of the market," Steiffer declares.
While methacrylic acid primers are to a certain extent a commodity (in that there is little variation between one manufacturer's product and another's), manufacturers caution that there are formulation differences that can affect: performance. Lin Halpern, director of research and development for NSI (W. Conshohocken, Pa.), explains that the concentration of methacrylic acid in a given primer can range anywhere from 50% to 100%. Primer manufacturers may use different solvents to dilute the concentration of methacrylic acid in primer. However, she notes that the solvents are inert ingredients that evaporate from the nail. The difference between brands lies mostly in the concentration of methacrylic acid.
While by far the dominant force, methacrylic acid primers have their drawbacks; most notably, they have caused some serious burns due to mishandling (see "Child-Resistant Packaging for Primer?" at end). The industry has demanded primer alternatives and several companies offer "non-acid" or gentler primers. "Non-acid" is really a misnomer since these primers do contain an acid as the active ingredient. Schoon notes that the non-acid primers are less corrosive, which means they are less likely to cause skin irritation.
The way they work is similar to methacrylic acid primers, says Sunil Sirdesai, OPI Products' chemist (N. Hollywood, Calif). "Bondex (the company's non-acid primer, which was introduced in 1988) forms an extremely strong ionic bond with the amino acids in the nail plate and a covalent bond with the monomer," he explains. "It increases the chain length between the functional groups and it has a larger molecular size, thus making it difficult for the molecule to enter the pores. This lack of penetration makes Bondex less irritating than conventional primers.
"Our data shows, and our customers tell us, that Bondex works as well or better than methacrylic acid-based primers. Due to individual differences in body chemistry, we do not all react the same to everything, whether it's foods, medicines, or cosmetics," he concludes.
"Non-acid primers still have not been proven to work across the board," Halpern responds. "But in their defense, methacrylic acid doesn't work across the board, either. My stance on non-acid primers is that they're worth trying, but don't expect them to work on all your clients. If you do find they work on even 30% to 50% of them, then they're worth using on those clients."
A Primer-Less Industry?
Looking to improve Creative's flagship product Radical, Schoon discovered a new combination of chemicals that resulted in a monomer that created a covalent bond - the strongest bond of all — directly with the nail plate. That product was Retention. "In fact, we found if we applied primer it actually weakened the bond," he says.
For the most part, the product has received favorable reviews from new users and the 50 salons that tested it while it was in development. However, some nail technicians, while pleased with its adhesion properties, were less than thrilled with an unexpected "side effect," which is green nails.
Schoon says the company is well aware of the complaints about an increased incidence of pseudomonas bacterial infections on the nails, which stain the nail surface green, but says it's a (law of technicians' technique and not of the product. "We knew this would happen with technicians who don't properly prepare the nail plate. If they don't use a nail prep product, then our product will fail."
Another issue, too, with Retention is color stability. "It's not as good as Radical," Schoon admits. "This product is more sensitive, and if you do certain things with it then it will discolor. For example, some substances — like nail enamel that contains formaldehyde — can change the surface color of the nail. There are a few other factors affecting color stability that I haven't quite nailed down."
For these reasons alone, Schoon and other manufacturers say the ideal primer-less acrylic monomer is still a thing of the future, although Retention takes the industry one giant leap closer.
"Nail technicians want more than adhesion," Schoon declares. "They want good workability and smile lines. It's more than just adhesion. There's no perfect product — one that give nail technicians every quality they want — just yet. What I do think is that Retention will spark innovation with other companies and products will improve."
Child-Resistant Packaging for Primer?
When a two-year-old child left unattended with a bottle of methacrylic acid primer poured the primer over herself, burning her skin quite badly, one of the doctors who treated her burns also wanted to treat whet he saw as the bigger problem: primer bottles with screw-on caps that are easily removed. The doctor wrote an article on the product and the child's resulting injuries for a professional journal, and at the same time wrote a letter to The Consumer Product Safety Commission (CPSC) advocating the commission mandate child-resistant packaging for methacrylic acid primers.
The child was not the first injured by methacrylic acid primer, but the several incidences over the years represent a minute percentage when compared to the hundreds of thousands of bottles of pnmers sold. However, the CPSC says it has started an investigation into whether child-resistant caps are warranted.
"Child-resistant packaging is a very effective safety measure." says CPSC spokesperson Ken Giles. "It saves hundreds of lives each year. The commission first plans to determine how many injuries and poisonings have occurred as a result of methacrylic acid primers, how toxic the chemical is, and how widely children are exposed to it.” If in fact there is little or no child exposure, then there may not be a basis' for it."
Still, the Nail Manufacturers Council (NMC) already anticipates regulations requiring the packaging, and president George Schaeffer says the association is taking proactive measures "We got proactive as a manufacturers' group and decided to offer something that would be child-resistant and yet still be usable for nail technicians," he says "One of the most important concerns with child-resistant caps is that the pressure it takes to open these caps could cause the bottle to slip and spill, which could cause more harm than the few cases already reported in relation to the millions of bottles of primer that have been sold"
Developing child-resistant packaging can be a costly venture, as it would require a new cap design and molds to make them, which could cost upward of $40,000 per mold for this reason, Schaeffer says the NMC and the ABA have proposed developing new, patented packaging that would be available to ail primer manufactures "The NMC is absorbing the patent cost because we feel it's better to go as a group than to have 50 companies getting together individual items approved and made. Schaeffer says the NMC would use an independent firm to traffic the orders so that companies could keep confidential their sales volume.
Not all manufacturers are thrilled with the idea, however "Companies that decide to put a child-resistant cap on their product are saying it's a consumer product," says Larry Gaertner president of No Lift Nails (Garden Grove, Calif) "Consumers shouldn't get anywhere near primer" Instead, Gaertner would like to see manufacturers tighten their distribution of primer and remove it from sample kits "We removed our methacrylic acid primer from our trial kit and replaced it with our Gentle Prime, which is a non-acid primer;" he notes "We also made it a 1 /8-oz bottle instead of a l/4-oz
"If the CPSC deems child-resistant packaging necessary fine," he adds "But let them decide whether it’s necessary or not their report hasn’t even been completed"
According to Giles part of the CPSCs research efforts will be aimed at the form in which children are exposed to methacrylic acid primer, and he says one option may be to regulate it only in cases where it is aimed at the home user "For example, there are household drain cleaners, which require child-resistant caps and there are industrial drain cleaners which don't," he says "We are in the earliest possible stages of our report; we are just beginning to gather information."
Regardless of the official outcome, common sense dictates keeping primer where it belongs — in the salon — and children where they belong — which is nowhere near workstations on product storage areas.