Contamination can have a nasty habit of creeping up on products. Philip Payne suggests how to try to ensure this doesn't happen in the first place but how to control it if it does
In recent years, the cosmetics industry appears to have had a good record for safety and quality. Compared with food products, cosmetics have been subject to relatively few recalls. Accurate figures are not easy to come by, but as some indication the US Food & Drug Administration reported more than 100 food recalls in 2008 whereas it reported less than ten for cosmetics/skin creams. That said, the first recall for 2009 was for make-up remover contaminated with Pseudomonas aeruginosa, an organism frequently cited in previous years as the reason to recall products such as shampoos, eye drops, skin creams and other cosmetic products.
However, while it might be tempting to think the above figures demonstrate a near faultless performance from the C&T industry, they also indicate areas of vulnerability. For example, there have been several recalls and alerts in both the food and pharmaceutical sector, particularly involving ingredients and raw materials sourced from China. Those with the highest profile include the contamination of milk with melamine, the contamination of heparin with over-sulphated chondroitin sulphate and the contamination of toothpaste with diethylene glycol (DEG).
Clearly all of these cases show that nothing can be taken for granted and there is limitless potential for poor quality supplies to create problems for all kinds of products.
PREVENTION IS BETTER THAN CURE
Prevention is certainly better than cure when it comes to problems, and that is not only true with respect to contamination.
With cosmetic products relying on more and more varied natural ingredients, there are many potential problems to address, such as ensuring that ingredients are authentic, or that allergens are not accidentally mixed with non-allergenic supplies, or that claims of stability, safety and efficacy can all be justified. It is far better to have a routine testing strategy that confirms the quality of supplies than to have this challenged and found wanting once the product is out on the market.
To this end, some rather sophisticated chemistry and investigative science may need to be employed. Sadly, there are no simple test tube methods that can show that an expensive oil has not been adulterated with a cheaper oil, or that a grape seed extract contains the expected levels of procyanidins, or that natural tocopherols are giving an oil its vitamin E activity, and so on. Manufacturers need to work with their own laboratories, or a reliable contract laboratory, to establish methods that are capable of determining the authenticity and quality of supplies, and they need to use those methods as a routine check that standards are being maintained and specifications are being adhered to.
Of course just because a high quality ingredient is added during production, there’s no guarantee that it will remain stable once the product is in use, or even as it leaves the production line. It is well known that certain vitamins, for example, may degrade when exposed to light or air, and the same may be true for the far less well characterised chemicals found in many natural ingredients. Chemical degradation and/or physical separation are both potential problems that need to be addressed by stability studies.
TROUBLE SHOOTING
Even where manufacturers produce cosmetics and toiletries to the highest standards, with strict specifications, something can still go wrong. There are vulnerabilities at every point in the supply chain and when contamination occurs, or is suspected, there is always an urgent need for the incident to be investigated and fully explained.
Having accurate results available quickly is key to making the right decisions about withdrawing a product or continuing with production.
The double requirement for accuracy and speed in an investigation of contamination incidents was the rationale behind the formation of the Emergency Response Service (ERS), established by Reading Scientific Services Ltd over 20 years ago. The ERS has now investigated more than 10,000 incidents involving a wide range of consumer products. An essential aspect of the ERS is its ability to draw on the company’s multi-disciplinary expertise in areas including chemistry, microscopy and physical sciences. After all, chemical off-odours can have a microbiological cause, and precipitates may result from chemical imbalance, so many investigations require this multi-disciplinary approach.
CHEMICAL CONTAMINANTS
A chemical contaminant will often reveal itself through laboratory analysis during a routine QC inspection, or through the consumer reporting an off-odour, off-colour or adverse reaction to the product.
Where chemical contamination is suspected, the investigation starts by repeating the usual QC procedure, with the intention of revealing a rogue peak on the chromatogram. Assuming the contaminant was initially identified by routine QC checks, it is important to verify the test result and to rule out the possibility that the QC test itself was at fault.
Whilst it is unusual for QC checks to cause a problem, rather than merely to reveal it, it is worth remembering that sources of contamination are frequently hard to anticipate and as a consequence hard to eliminate. Indeed elimination may be impossible. For example, some chemicals will inevitably give rise to degradation products. Provided these are well characterised, and present within the permitted levels, their presence will cause no concern, but they are still technically contaminants.
It is ironic that production equipment, including the very items installed to protect the product from other problems, can themselves be the source of contamination. Plastic monomers and oligomers can leach out of on-line filters into solutions, or from plastic seals, pipes and packaging. It takes very little migration to produce a detectable taint in unscented products. Similarly, chemicals from cleaning solutions, cooling waters and machinery lubricants are occasionally found in products.
FOREIGN BODIES
Microscopy is always the first line of attack in investigating foreign body incidents. Light microscopes may yield useful information on their own. However, scanning electron microscopes linked to X-ray microanalysis equipment or X-ray microfluorescence equipment may also be used. Both can reveal the elemental composition and distribution within a sample and are especially valuable in the analysis and comparison of glass and metallic fragments. FT-IR microscopy is similarly powerful in identifying small organic particles.
Whilst glass, metal and plastic fragments from plant and packaging constitute the majority of foreign body cases, they are by no means the only cases. Insect body parts, human hairs, pieces of paper, drops of silicone and unknown ‘black bits’ are also common.
Contamination can take many forms – chemical, physical and microbiological, or a combination of all three. Prevention is always better than cure, but while it may not be possible to prevent every incident, it is always possible to investigate every case. It is only with good information that good decisions can be made as to how to respond to an incident.
ALLERGENS - A SPECIAL CASE
One class of chemical contaminant worthy of special attention are allergens. Many products use natural oils as the base for creams and lotions, and they may be processed in facilities that also handle nut oils and fish oils. Both nuts and fish can be allergenic, and since there is no safe exposure limit, any cross contamination represents a serious risk to sensitive individuals.
Allergen management is one issue that the food industry has had to address now that EU and US labelling regulations insist on all allergens being listed on labels. In fact it is the failure to label, rather than intrinsic problems with safety, that account for roughly 50% of all food recalls in the UK and the US, perhaps putting the food vs cosmetics statistics into some perspective.