For years, environmental activists have been encouraging consumers to embrace cold water washing. It was a slow uptake, for one simple reason: cold water washing didn’t work as well. Consumers weren’t willing to compromise efficacy, even for the sake of the environment, or reduced energy bills.
Here’s a look at the benefits of cold water washing, obstacles to adoption for consumers, and the ingredient categories that have changed the laundry business for good—and for the good of the planet.
Why is cold water washing so important, what’s holding consumers back, and how can the industry overcome these obstacles?
Primary benefits
Cold water washing demonstrates benefits on at least two important fronts:Benefit #1: Better for the environment
Did you know, 90 percent of the energy used by washing machines during laundry goes to heating the water?1
Therefore, choosing cold water for four out of five loads of your laundry could prevent 864 pounds of CO2 emissions in a single year—just for your household alone.2
Benefit #2: Better for household energy budgets
The energy costs associated with washing a single load of laundry in hot water costs an estimated 1700% more to the consumer versus washing and rinsing in cold water.3
With an uncertain economy and the threat of recession looming, cold water washing is a simple way to reduce household energy costs.
Consumer obstacles
Despite clear benefits to both the environment and to household energy budgets, there has been a longstanding perception that cold water isn’t as effective as washing in warm or hot water.While that was the case historically, advancements in detergent formulations have dramatically enhanced the efficacy of cold water washing. Nevertheless, myths surrounding cold water washing still remain:
Myth #1: Cold water washing doesn’t get my clothes as clean
With the right ingredients, tests have shown that washing at colder temperatures can produce comparable results to hot water wash cycles.4
Myth #2: I need to use hot water if I have stained clothing
Contrary to popular belief, hot water is not always the best option for stubborn stains. In fact, exposure to hot water can actually set some stains—grass, makeup, and blood—thus making them more difficult to remove.5
The bottom line: Detergent formulations have come a long way in our lifetimes. It has been nearly 20 years since cold water formulations were first introduced to the market, and since that time, ingredients and formulations have matured. Today’s top-performing detergents are designed to be highly effective for a wide range of fabrics and stains at the full spectrum of temperatures.
Key solutions
There are four primary categories of solutions that have arisen in cold water laundry formulations: surfactants, polymers, enzymes, and optical brighteners. Here’s an overview of each:Surfactants
Surfactants are not a revolutionary ingredient. However, it’s the types of surfactants that have enabled cold water washing.
Two types of surfactants may be part of an optimized surfactant system for lower temperature applications: branched surfactants, which typically carry a better solubility profile; and short chain surfactants, which dissolve stains more quickly in comparison to longer chain surfactants.6
At BASF, we offer Lutensol® CS 6250 and Lutensol XP 40, both of which are designed to clean in cold water. Other Lutensol surfactants are also great for cold wash. For example, when combined with an anionic surfactant, nonionic surfactants like Lutensol LA 60 and Lutensol A 65 N usually result in a more lipophilic mixture, which means the system is likely to be more effective against oil-based stains.9 Additionally, ethoxylated Lutensol surfactants demonstrate superior solubility in water at lower temperatures. The polyethylene glycol chains on these molecules can form hydrogen bonds at lower temperatures thus improving their solubility in cold water.7
Polymers
Relative to surfactants, polymers tend to be less affected by temperature, making them essential for many cold-water wash formulations. Extremely versatile, polymers in detergents can be used as anti-redeposition agents, de-foamers, dye transfer inhibitors, detergency boosters, and more. Additionally, some polymers can even help tackle stains. For example, Sokalan® HP 30 Booster, an alkoxylated polyethyleneimine (APE) polymer, has been found to be effective against oily stains at low temperatures.8 Conversely, Sokalan HP 20, an ethoxylated polyethyleneimine polymer, shows better performance against enzymatic stains such as chocolate syrup, grass and tea. Interestingly, the combination of these two different polymers results in a synergistic effect where broad-spectrum stain removal performance is observed under cold wash conditions.
There is evidence that the inclusion of APE polymers can also reduce the viscosity and increase the solubility of liquid detergents in cold water. This effect is especially important for unit dose detergents, which take more time to dissolve compared to consumer-measured detergents.9
Enzymes
Enzymes play a critical role in breaking down stains because they are highly effective against stains that need to be “digested” prior to removal, such as egg, grass, cocoa, starch, and more.10 As effective catalysts, even at low temperatures, each enzyme degrades a specific substrate and common ones in laundry applications include proteases, amylases, cellulases, and mannanases.
For example, oil and starch-based stains are often harder to clean in cold water because the stains become solid and do not dissolve in a standard wash cycle. However, enzymes such as lipases and amylases are still able to degrade these stains—even when the starches and fats are solid.11 Surfactants alone can also have a difficult time tackling protein stains in cold water, but the addition of proteases like Lavergy® 114 LS can help break down these tough stains.
Furthermore, innovation has driven scientists to design enzymes that can withstand the harsh conditions of a laundry detergent. In the past, stability was a significant hurdle because enzymes would denature under alkaline conditions or when exposed to surfactant and bleach ingredients. However, modern enzymes like BASF’s Lavergy enzymes are generally compatible with standard detergent formulations, and can now be used under pH 7-9 conditions with temperatures as low as 15 °C.
Optical Brighteners
Optics are a powerful element of consumer perception. For that reason, loads of white fabrics are perhaps the most likely to be washed using hot water since consumers assume that hot water is required to achieve and maintain the desired color and brightness.
Optical brightening agents (OBAs) can be used to improve the perceived whiteness of clothes. These compounds absorb UV light and re-emit visible blue light via fluorescence. This “bluing” effect is perceived by the human eye as whitening. But not all OBAs work equally well at low temperatures—some are more effective than others. For example, Tinopal® CBS-X is a stilbene-biphenyl-based OBA and is more water-soluble than other stilbene-based alternatives. Solubility is dependent on temperature, and it generally tends to decrease under colder conditions. Therefore, it’s important to choose ingredients with better solubility profiles for cold water washing—ingredients like Tinopal CBS-X.
Future outlook: Where is the market going?
Cold water washing is an approachable pathway to reducing carbon footprint at home. Now that cold water wash is possible without sacrificing efficacy, and many consumers find themselves looking for ways to tighten the family budget, the market can expect to see increased demand for products that embrace this potential.References
- American Cleaning Institute®. Industry Priorities: Cold Water Saves. https://www.cleaninginstitute.org/industry-priorities/outreach/cold-water-saves
- American Cleaning Institute® & The Sustainability ConsortiumTM. Cold Water Saves. https://coldwatersaves.org/source.html
- Mars, Carol. The Sustainability ConsortiumTM. Technical Brief: Benefits of Using Cold Water for Everyday Laundry in the U.S. https://www.cleaninginstitute.org/sites/default/files/assets/1/Page/Cold-Water-Wash-Technical-Brief.pdf
- Mars, Carol. The Sustainability ConsortiumTM. Technical Brief: Benefits of Using Cold Water for Everyday Laundry in the U.S. https://www.cleaninginstitute.org/sites/default/files/assets/1/Page/Cold-Water-Wash-Technical-Brief.pdf
- American Cleaning Institute® & The Sustainability ConsortiumTM. Cold Water Saves. 2022. https://coldwatersaves.org/source.html
- Miller, Clarence A., and Kirk H. Raney. “Solubilization—Emulsification Mechanisms of Detergency.” Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 74, no. 2-3, 1993, pp. 169–215., https://doi.org/10.1016/0927-7757(93)80263-e.
- Cheng, Kai Cong, et al. “Design and Performance Optimisation of Detergent Product Containing Binary Mixture of Anionic-Nonionic Surfactants.” Heliyon, vol. 6, no. 5, 2020, https://doi.org/10.1016/j.heliyon.2020.e03861.
- BASF. Market Insights: New Performance Polymer from BASF Delivers Superior Oily Stain Removal at Low Temperatures. August 2021. https://www.hcii.basf.us/market-insights/new-performance-polymer-from-basf-delivers-superior-oily-stain-removal-at-low-temperatures
- Ibid.
- Ibid.
- Van der Maarel, Marc J.E.C, et al. “Properties and Applications of Starch-Converting Enzymes of the α-Amylase Family.” Journal of Biotechnology, vol. 94, no. 2, 2002, pp. 137–155., https://doi.org/10.1016/s0168-1656(01)00407-2.