The topic of "why don't people like to buy black underwear" appeared on Weibo hot search, causing heated discussions.
Black is one of the most common colors of textile and garment products, for the online rumors that "often wearing black underwear is prone to cancer" and "black clothes are dyed with poor quality fabrics", many netizens questioned whether it is true or fake?
So, is there a scientific basis for this claim?
Most countries have banned harmful dyes
"Including black dyes, the dyes currently used in the mainland textile industry are mainly chemically synthesized dyes. These dyes themselves are not toxic. Song Lidan, an engineer at the China Textile Construction Planning Institute, said.
According to the data, azo dyes are currently the largest chemical synthetic dyes, which are often used in the dyeing and printing of a variety of natural and synthetic fiber fabrics. "Azo dyes themselves are non-toxic, but a small part of azo dyes will reduce their reactions with human metabolites under certain conditions, releasing carcinogenic aromatic amines and harming human health. Song Lidan said.
However, this part of the azo dye has been banned in most countries, including the mainland. The national mandatory standard "National Basic Safety Technical Specifications for Textile Products" (GB 18401-2010) clearly stipulates that "decomposable carcinogenic aromatic amine dyes are prohibited".
"Textile and apparel products sold in the mainland market must comply with the provisions of this mandatory standard. The above provisions are also applicable to black textile and garment products, so black clothes of qualified quality are safe and harmless. Song Lidan said.
Pay attention to the product label when purchasing
Some consumers reported that some black textile and clothing products would "dye" their skin black after wearing. Song Lidan believes that there are two main reasons for this situation: one is the dye residue caused by insufficient washing of clothes in production, and the other is that the dyefastness of the product is not up to standard, and the color is transferred to the skin under the sweat soak or in the process of rubbing against the skin.
The National Basic Safety Technical Code for Textile Products (GB 18401-2010) stipulates five levels of dye fastness, and proposes that infant textile products should meet the requirements of Class A, products in direct contact with the skin should at least meet the requirements of Class B, and products in direct contact with the skin should meet at least the requirements of Class C.
Song Lidan suggested that consumers should choose products that meet the requirements of Class A or Class B when buying textile and clothing products that are in direct contact with the skin, and products that meet the requirements of Class A when buying infant textiles.
In addition to this, there are also people on the Internet who have suggested that "poor quality fabrics are often dyed black to cover up the flaws on the fabric". Is this a credible claim?
Song Lidan said that at present, the fabric weaving of the modern textile industry has achieved large-scale automation and intelligence, and the control level of fabric quality of relevant enterprises has also been greatly improved. Some companies have applied artificial intelligence visual inspection technology to realize online monitoring of fabric quality.
"From weaving to dyeing of a roll of cloth, the company will determine what weaving structure and what color the cloth is dyed in the design stage. In the weaving process, the company will carry out quality inspection and monitoring of each link to improve quality and reduce the defect rate. Song Lidan said that at this stage, it is almost impossible to dye the defective fabrics black.
"When purchasing clothing, consumers should buy products with quality assurance from formal channels, and check whether the product has a complete logo or tag, including whether the product name, product standard number, manufacturer's name and address, product number type or specification, safety category, fiber composition and content, maintenance method, product quality inspection certificate, etc. Song Lidan reminded that it is recommended to buy carefully for clothing with unclear labels, unknown labels, and low prices. In addition, consumers should properly wash the newly purchased textile and clothing products, especially those that are in direct contact with the skin, and wash off the floating colors that may exist on the products, so that they can wear them with more confidence.
Source: "Science and Technology Daily" WeChat public account