Three years ago, Novozymes launched two new liquid detergent proteases: Savinaser Ultra and Alcalaser Ultra. These proteases are unique; they contain a built-in stabiliser, which means that detergent manufacturers can take out boric acid and reduce the dosage of expensive polyols such as propylene glycol in liquid detergents. The money saved has allowed manufacturers to increase the type or number of enzymes present.
Now there is another reason to choose one of the 'Ultra' proteases: the European Union proposes to reclassify boric acid as a 'reprotoxic' agent that 'may impair fertility' or 'may cause harm to the unborn child'. Depending on the maximum accepted levels for boric acid, manufacturers of liquid detergents in Europe may be forced to include these warnings on their labels, reduce the amount of boric acid to avoid doing so, or find alternatives to boric acid.
The background
Novozymes has been carrying out research into stabilisers for use in liquid detergents for more than 15 years. The problem is that, in liquid form, proteases are free to move around in solution and degrade other enzymes or proteases (autoproteolysis). This can greatly reduce the efficacy of any liquid-based enzyme-containing detergent. Of course, this problem does not occur in powder detergents due to the lack of water.
To get around this problem, detergent manufacturers and formulators have traditionally added stabilisers such as boric acid and polyols, e.g. propylene glycol. A typical enzymatic liquid deter gent contains 3-5% polyols and 2-3% boric acid; polyols are always needed in a complex with boric acid and may also be needed for other functions.
Pre-stabilised proteases
In the late 1990s, Novozymes developed a stabiliser that was one hundred times more effective than boric acid, and this stabiliser is now added to two pre-stabilised pro-tease types: Savinase Ultra 16 L/16 XL and Alcalase Ultra 2.5 L/2.5 XL (the XL versions contain extra stabiliser). Thus, the two well-known liquid proteases are also available with a built-in stabiliser.
Currently, many liquid detergents contain around 2-3% boric acid. In the second half of 2005, the European authorities proposed to reclassify boric acid/borates as Reprotoxic Category 2 and to set specific concentration limits for their permitted use in products. However, by the end of October, the upper limit had still to be decided. In future, any manufacturer exceeding the limit may be obliged to include a warning on the packaging, including a skull-and-crossbones and two statements:
- 'May impair fertility'
- 'May cause harm to the unborn child'
Niels Kildegaard Pedersen, senior marketing manager for Detergent Products at Novozymes, says: "Although these statements may appear to be unduly alarming for an ingredient that has been used safely for many years, there is no doubt that it might upset end-users. This is why it is fortunate that Novozymes has developed these two proteases that do not need stabilisation with boric acid."
"Consumers like the convenience of a liquid, and it is perceived that liquid detergents are more gentle on clothes during the laundry process."
Cost-savings
Another benefit for manufacturers using Savinase Ultra and Alcalase Ultra in their liquid detergents is the potential for cost-savings. Boric acid/borax needs to be solubilised prior to incorporation into a liquid detergent, which is costly and time-consuming as well as adding to logistical problems for many manufacturers.
"What we've found in the past is that Alcalase Ultra and Savinase Ultra have been particularly popular with producers who are getting into the enzymatic liquid detergent segment for the first time due to cost-savings," says Niels Kildegaard Pedersen.
"More established manufacturers have tended to maintain their use of boric acid and polyols. However, this is bound to change with the new regulations. Indeed, some major global manufacturers have already taken the decision not to use boric acid, and it is Novozymes' aim to preserve customers' investment in liquid detergents by offering them these two pre-stabilised proteases."
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”The development of Savinase® Ultra and Alcalase® Ultra is the fruit of a deliberate, focused research project,” says Niels Kildegaard Pedersen, senior marketing manager for Detergent Products at Novozymes. |
Trends in detergent use
The importance of maintaining the availability and efficacy of liquid detergents is evident in trends for detergent use. In the USA, where liquid detergents are particularly popular, around 70% of all detergents used for laundry are liquid-formulated. In Europe, the figure is 25%, but the rate of growth is high.
"Consumers like the convenience of a liquid, and it is perceived that liquid detergents are more gentle on clothes during the laundry process. In the early days of liquid detergents, they were not as efficient as powders. But things have changed since then, and now the cleaning power is much the same," says Niels Kildegaard Pedersen.
Timelines for changes
The 'reprotoxic' classification proposal made by the EU Commission needs to be formally adopted by the member states in a vote. (No date had been set for a vote at the time of writing.) Once the proposal has been adopted, manufacturers and producers will have around 18 months to implement the changes. However, earlier moves away from boric acid will occur. The proposal will only affect those European countries that are members of the EU.
"I think it's likely that any moves towards this type of labelling in the EU will be repeated in other countries like the USA before long. Usually, California and Florida are at the forefront of the US states when it comes to implementing these types of change," says Niels Kildegaard Pedersen.
Focused research
"I think it's important for our customers to know that the development of Savinase Ultra and Alcalase Ultra is the fruit of a deliberate, focused research project on protease stabilisers that has been going on for well over a decade, rather than just a knee-jerk reaction to this new EU Directive. We want to maintain our customers' success with liquid detergent formulations so that they can continue to meet the needs of end-users who seem to prefer liquids to powders. Hopefully, the 'Ultras' will help them to achieve this," he concludes.