Dry cleaning clothes is cheaper than water washing: Experts explain three misconceptions about laundry

Will clothes sent to the dry cleaner be washed with water? Does dry cleaning solvent harm the skin? Does washing clothes at home with cold water at room temperature remove all bacteria? Does dry cleaning kill all germs? The answer to all these questions is no. On June 7, the Provincial Laundry and Dyeing Industry Association, together with the Provincial Consumer Council, the Municipal Economic and Trade Commission, the Municipal Administration for Industry and Commerce, and the Municipal Consumer Council, held a "Laundry Service Process Open Day" at the Tiantian Laundry Zengcheng Factory. They invited over a hundred citizens and well-known social figures as "Laundry Observers" to have close contact with and inspect the laundry process on site, and explained common "laundry misconceptions" to the public.

Several experts explained laundry technology, stating that textiles washed in cold water or water below 60°C can carry infectious pathogens and contaminate the entire laundry process, making the sterilization effect of washing not obvious. Large laundry factories invest heavily in equipment upfront, but the dry cleaning cost per garment is lower than water washing, so laundry factories would not pretend water washing is dry cleaning just to save costs. Instead, many unlicensed small laundry shops, lacking qualified dry cleaning equipment, can only substitute dry cleaning with water washing.

Misconception 1

Does washing clothes with cold water at room temperature remove all bacteria from the clothes?

Fact: Even after high-temperature water washing, dry cleaning, and high-temperature ironing, some stubborn bacteria and pathogens may still remain on clothes.

Dirty clothes are very dirty and actually contain many bacteria. Studies show that dirty clothes contain specific microorganisms such as Staphylococcus aureus, Escherichia coli, or pathogenic bacteria.

"Generally, when we wash clothes at home, we use cold water at room temperature, but this washing effect is not obvious," said Shi Jianrong, an expert from the Provincial Laundry and Dyeing Industry Association. Textiles washed in cold water or water below 60°C can carry infectious pathogens and contaminate the entire laundry process. Many pathogens can even survive in dry environments, such as Salmonella, hepatitis A virus, and rotavirus. Once these viruses spread through dirty clothes, they can cause diarrhea, wound infections, respiratory infections, and other diseases, endangering human health.

Shi Jianrong said that only washing clothes, linen, towels, flannel, and other textiles at temperatures above 60°C can kill pathogens. How to sterilize at low temperatures? Low-temperature washing must use clothing disinfectants to kill pathogens.

Additionally, clothes washed with water can be effectively sterilized by the high temperature of a dryer, preventing pathogens from breeding in a damp environment. Clothes can also be ironed with high-temperature steam to kill some bacteria and pathogens.

If clothes are dry cleaned, the addition of tetrachloroethylene with sterilizing properties during the dry cleaning process can kill germs, mites, and moth larvae, effectively eliminating pathogenic bacteria on clothes.

"However, even after high-temperature water washing, dry cleaning, and high-temperature ironing, some stubborn bacteria and pathogens may still exist on clothes," said Shi Jianrong. At this point, the "trump card" can be used: ultraviolet and ozone disinfection to ensure that bacteria and pathogens on clothes are completely removed, guaranteeing cleanliness and hygiene.

Li Jingjin, founding president of the Taiwan Franchise Chain Association and vice president of the Cross-Strait Chain Operation Association, introduced that washing clothes at home cannot achieve sterilization and disinfection. Many citizens mistakenly believe that drying clothes under the sun is better, but poor air quality can cause secondary pollution. Large laundry factories have more professional machines and equipment, disinfecting and sterilizing through multiple procedures. In places like Japan, South Korea, Taiwan, and Hong Kong, citizens are accustomed to sending clothes to laundry factories.

Misconception 2

Does mixing clothes during washing cause cross-contamination of bacteria?

Fact: During dry cleaning, adding tetrachloroethylene disinfectant can separate dirt and bacteria and wash them away together.

On the 7th, citizens visited the entire laundry process at Tiantian Laundry Factory during the open day. Some citizens saw clothes being sent one by one into 18 dry cleaning machines. "If clothes are washed mixed together, will bacteria cross-contaminate?" Many citizens raised doubts on site, worried about laundry hygiene. Some also pointed out that dirty clothes are usually piled together when collected by laundry shops.

In response, Shi Jianrong, an expert from the Provincial Laundry and Dyeing Industry Association, said that if no disinfectant is added during dry cleaning, bacterial cross-contamination will occur. But by adding tetrachloroethylene disinfectant, dirt and bacteria in clothes can be separated and washed away with the disinfectant. The disinfectant also prevents bacteria from reattaching to clothes. After dry cleaning, clothes are further sterilized by high-temperature drying, and the tetrachloroethylene disinfectant evaporates at high temperature, leaving no residue on clothes.

"Some small laundry shops, due to inadequate equipment and processes, cause tetrachloroethylene disinfectant to remain on clothes, which can affect skin and health. Therefore, citizens should choose regular and qualified laundry shops and dry clean clothes according to strict procedures. Quality inspection departments will also regularly check whether laundry shops meet standards," said Shi Jianrong.

Misconception 3

Can sodium hydroxide solution determine whether clothes are dry cleaned or water washed?

Fact: Using sodium hydroxide solution to dissolve and test whether clothes are dry cleaned lacks scientific basis.

How to determine if clothes have been dry cleaned? Previously, some media reported that using sodium hydroxide solution can determine if clothes are dry cleaned. The Provincial Laundry and Dyeing Industry Association issued a statement saying this method lacks scientific basis and is insufficient to prove whether clothes have been dry cleaned.

The Provincial Laundry and Dyeing Industry Association stated that sodium hydroxide is a corrosive strong alkali, generally in flake or granular form, easily soluble in water (releasing heat when dissolved) to form an alkaline solution, and is highly hygroscopic, readily absorbing moisture from the air and becoming deliquescent.

Previously, some media wrapped sodium hydroxide granules in napkins and sewed them into clothes to be washed (according to footage, the clothes tested by reporters were all suitable for water washing), then sent them to laundry shops for cleaning, to determine whether the clothes were cleaned by dry cleaning or water washing.

In response, the Provincial Laundry and Dyeing Industry Association stated that since sodium hydroxide is a strongly alkaline chemical with strong corrosiveness and high water absorption, it can dissolve even by absorbing moisture from the air. The process of clothes being sent to the factory for washing takes two to three days, so the sodium hydroxide may have already dissolved before the clothes undergo dry cleaning. Moreover, the dissolved sodium hydroxide can easily seep out, causing fabric corrosion, discoloration, dye loss, and contamination of other clothes. Clothes with sewn-in sodium hydroxide granules can still have most of the sodium hydroxide dissolved even if placed in a dry cleaning machine.

The expert investigation team conducted a sodium hydroxide dry cleaning test. First, they used tetrachloroethylene dry cleaning solvent, wrapped sodium hydroxide in a clean napkin, and sewed it onto the clothing label. After washing for 6 minutes and drying for 30 minutes, they found that two-thirds of the sodium hydroxide wrapped in the napkin had dissolved, causing severe discoloration of the clothes. The entire white napkin was stained blue from the clothes, proving that this test lacks scientific basis.

Li Jingjin introduced that large laundry factories have high initial equipment investment, but the dry cleaning cost per garment is lower than water washing. Laundry factories would not pretend to dry clean by using water washing to save costs. Instead, many unlicensed small laundry shops, lacking qualified dry cleaning equipment, can only substitute dry cleaning with water washing.

Li Jingjin revealed that the general dry cleaning cost per garment includes washing, drying, ironing, packaging, delivery, compensation, depreciation, management, store and factory rent, and front desk expenses, totaling about 8.9 to 16.9 yuan per piece, while water washing costs about 9.2 to 17.3 yuan per piece, making water washing more expensive than dry cleaning. Additionally, dry cleaning machine oil can be recycled through distillation. The washing and drying time for dry cleaning is about 40 minutes, whereas water washing takes more than 80 minutes. Legitimate large laundry factories would not substitute dry cleaning with water washing to save costs.