Managing microbial risk in the environment of a personal care facility is a difficult task. Personal care products are frequently made from non-sterile raw materials obtained from several suppliers in non-sterile facilities, thus risks to the product and consumer can arise from starting materials, operations, people, inadequate cleaning and sanitisation or from facility construction or changes.
With fewer and fewer preservatives permitted for use by the regulators, proactively assessing the risks and then managing them is the only way that companies can make products safe and ultimately stay in business.
Microbes may be benign in some products for some people, but in other products they can make particular groups of consumers critically ill
It is the role of the microbiologist to assess, manage and communicate those risks effectively to the management. But unless that management has a good understanding of microbiology, this latter task can be immense. Microbiological risk presents a particular challenge for non-microbiologists to fathom, explained Neil Lewis, Global Household Care Microbiologist, Procter & Gamble. Because most people (chemists, engineers and other disciplines) think in absolutes, they find it hard to deal with microbial risk, he said. Microbes can arrive from several places, grow from a few numbers to large colonies in a short space of time, move and migrate, withstand the harshest of conditions and are invisible to the naked eye. They may be benign in some products for some people, but in other products they can make particular groups of consumers critically ill.
For Lewis, the key factor is making sure that the recipients of any assessment report understand the risk at the end of the process. ‘They may want a simple answer, but often there isn’t one,’ he said. ‘In the sterile field everything is defined but in the non-sterile field it is harder to know what the risk is, as it depends on the process, the number of people in the facility, the environment and many other factors that can vary at any time.'
To manage this risk requires technically qualified people who understand it and who can assess the scale of the risk and put it into context, Lewis said, adding that it is also important to use a scoring method that gives a clear indication of whether action is needed.
Risk assesments are subjective, however, and can be biased, he said. ‘If financial pressure is brought to bear and money needs to be spent to put a bad system right, the risk assessment wording can become ambivalent, and transparency is lost,’ he warned. However, he added, if the risk assessment is transparent and makes it clear that particular people are accountable for the decision they take, they will think more carefully about it.
The risk is often a function of product exposure to the environment, so to have data that show the environment is a risk – e.g. through particle counting – helps to quantify it, said Lewis.
Raw materials are a risk factor and supply needs to be managed. The supplier risk can be quite small when good quality controls on incoming raw materials are in place. However, when dealing with commodity materials delivered by a tanker and from variable suppliers, the situation is much riskier and complex.
The more work and the faster operations need to be, the greater the risk that operators will cut corners
‘If contamination occurred during unloading of a raw material from a tanker at the manufacturing facility (i.e. via a dirty hose in wet weather) who would be responsible?’ he asked. ‘Contracts need to be clear about at what stage during the transfer of an ingredient from the supplier’s tank to the facility does the responsibility transfer from supplier to manufacturer.’
Human operators present the greatest microbial risk, however, warned Lewis. The more work and the faster operations need to be, the greater the risk that operators will cut corners. ‘They may decide to deviate from written procedures and operate in a different way because it is quicker, or they think it is more efficient without understanding the implications of their actions.’
In such a situation, simply to retrain them in the same way again is unlikely to be successful. ‘Think of a better form of training involving “what if?” scenarios that will make them think it through for themselves,’ Lewis advised.When it comes to equipment design, he suggested companies should aim to design out manual procedures. ‘Ask of all new equipment, can we clean it? Sanitise it? Drain it?’ He suggested the use of borescopes and video equipment to see inside tanks and pipework and said: ‘Remember, you can only swab surfaces that you can reach, so make sure equipment has no inaccessible areas.’
Lewis also recommended the use of infrared cameras and thermocouples to show that when a vessel has been heated for sanitisation, it has actually reached the required temperature in all areas. It is also important to assess how long something can be safely stored after it has been cleaned and sanitised. ‘Even if it is clean and dry, this time is relatively short,’ he warned.
Computer-based tools
Dr Stefan Stumpe, part of Henkel’s Microbiology Team, talked about his company’s approach to risk assessment and hygiene. The company produces a wide variety of personal care, household, laundry and adhesive products, across a large number of facilities around the world. Henkel has created a computer-based tool for hygiene audits that enables the company to carry out a process of self-assessment to see whether plant hygiene is improving. The tool (which currently comprises 20 chapters) is broken down into three parts: Organisation, Technology and Product-related issues. It results in a grading system for all plants, which ranges from 1–5 (1 being critical, 2 serious, 3 fair, 4 good, 5 very good). It is the company’s expectation that each plant achieves at least a grade of 4 for each chapter, said Stumpe.
When it comes to equipment design, companies should aim to design out manual procedures
Because of the amount of change in such a large operation, Henkel carries out assessments annually. Each plant has a hygiene team, consisting of a trained microbiologist/quality person, an engineer, a production person and a maintenance person. Each plant receives a hygiene checklist to work through and at the end of the self-assessment procedure, the team gets a document (with pictures) that incorporates a ‘to do’ list of improvements, recommendations and mandatory actions.
According to Stumpe, the hygiene checklist is written in a very descriptive way, such that if any hygiene team member leaves the company, a new member would be able to understand it.
At the end of the assessments, the company is able to see clearly on the computer tool how different plants have improved, changing from red to green coding on a chart.
Waterborne risks
Richard Slindon, B&V Group, looked at understanding and effectively managing water systems, with specific reference to Legionella and Pseudomonas bacteria.
He said that when assessing the risks of Legionella, for example, it was important to look at whether the conditions exist that would allow the organisms to multiply, e.g. a temperature between 20–45°C and the presence of stagnant water. ‘Ask yourself, is the presence of Legionella in sufficient numbers? Is there a source of nutrients (sludge, scale, rust, protozoa, algae or other organic matter)? Is there a means of creating and disseminating fine droplets (cooling towers, showers or water draw-offs that may cause splashing)?’ he said.
Slindon went on to look at the effectiveness of various disinfectants. A UK National Health Service case study using shock-dosed active chlorine seemed to have many advantages, he said, adding that there will be no panacea and a combined approach of preventative measures will be needed to manage the risk.
Cleaning regimes
Carolyn Punter, Area Sales Manager, Ecolab, looked at cleaning issues in the cosmetics field and at how some of today’s ingredients create particular cleaning issues, and thus risks. She looked at putting science behind a cleaning plan. ‘Understanding the residue and designing case-specific cleaning plans which use the optimum parameters of temperature and pH of the cleaning agents can be beneficial,’ she said.
Heat can make some ingredients harder to clean and so the optimum temperature of cleaning water is important. Cellulose, for example, used as a thickener in shampoos and other products, can leave behind visible residue spots in production vessels. Ecolab studies reveal this material is best cleaned at low temperatures (20°C) and with neutral conditions.
Titanium dioxide can leave white spots that are visible only when dry. For this, it is essential to use demineralised water at low temperatures. If high temperatures are used, the residue matrix splits into organic and non-organic substances making it harder to remove.
Heat can make some ingredients harder to clean and so the optimum temperature of cleaning water is important
Carbopol or carbomers are used widely in products as thickeners as they swell to a gel on contact with water. Many cleaning agents will sit on the surface and water will not penetrate them. ‘Alkaline agents will make them swell, so to avoid this, don’t pre-rinse; use organic acid or chelating agents, or a salt solution that will disrupt the gel,’ she suggested.
In terms of cleaning silicones, water will clean some but not others and may leave an oil-like residue. For this she recommended a longer pre-rinse and cooler water with an alkaline solution and a removal additive comprising several surfactants. It might need an oxidative booster as well. Punter went on to look at equipment issues, such as achieving the required turbulent flow, avoiding deadlegs or sprayball shadows that leave some areas unwashed. She also looked at the impact of surface roughness on cleaning.
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