Detection Of Basic Safety Items For Eco Textiles And Textile Products

ecology

1 definition of eco textiles

The concept of "eco textiles" stems from the "Oeko-Tex Standard 100" issued by the International Eco textiles research and Inspection Association in 1992 (ECO textile standard 100).

There are two broad and narrow meanings:

1) generalized eco textiles

The generalized eco textile, also known as "eco textiles", refers to the whole life cycle of products from raw material manufacturing to pportation, production, consumption, recycling and disposal of products, that is, the so-called "cradle to grave".

Ecological textiles must meet four basic prerequisites: (1) resources are renewable and reusable; second, the production process has no pollution to the environment; (3) it is harmless to the human body in the process of wearing and using; 4. After being discarded, it can degrade naturally in the environment without polluting the environment.

That is, it has the characteristics of "recyclable, low pollution and energy saving".

Organic textiles refer to the processing, consumption and post-processing processes of textiles, which are environmentally friendly and pollution-free. Therefore, organic textiles are all eco textiles, such as organic cotton products.

Organic cotton is a natural and pollution-free process from seed to textile production. It is mainly managed by natural farming without using any pesticides, fertilizers and genetically modified products.

Due to the strict requirements for the whole ecological textiles, the organic textiles in the real sense need further research, which is the development direction of ecological textiles.

2) narrow ecological textiles

Narrow ecological textiles, also known as part of eco textiles or semi eco textiles, refer to products that are harmless or harmless to the environment at present level of scientific knowledge and are harmless to human health or reach the standards of an International Eco textile standard. They are mainly ecological products of production, human consumption or treatment.

At present, it is mainly aimed at testing the contents of ecological textiles in narrow sense.

2 detection of eco textiles

2.1 testing items for Eco textiles

The testing procedures for Oeko-Tex 200 (test standard) contain 12 main categories: pH value determination, formaldehyde determination, extractable heavy metals, pesticide residues, phenol (chlorphenol and OPP) content, banned dyes, organochlorine carrier, PVC plasticizer (o-phenyl two formate) content, organotin compounds, color fastness, volatile compounds and odor mixture determination, sensitive odor and so on.

It needs to be explained that the detection items of eco textiles are dynamic, and almost every year there will be some new indicators.

At present, the testing items of various testing institutions in China are: pH value determination, formaldehyde determination, extractable heavy metals, banned azo dyes, color fastness, odor and so on.

2.2 main technology of ecological textiles testing items

There are three main types of modern eco textile testing technology: chromatography, atomic spectroscopy and molecular spectroscopy.

Among them, chromatographic analysis technology is the most widely used.

2.3 product standards and labels for Eco textiles

There are many textile ecological standards in the world. ISO has classified the standards and labels of ecological products into 3 categories:

The first type is: first, inspect the whole life cycle of the product, that is, the extraction of raw materials, the pportation of products, production, use and abandonment; (2) voluntary participation; (3) multi product categories; (4) third party inspection and on-site audit representative ecological labels.

For example: Europen Eco-Label (EU eco label), Nordu White Swan Labe (Nordic Swan logo), The Blue Angel (German blue angel logo), Flower Label (European Union flower label), Angel (Canadian environmental selection protection label), Japan (ecological symbol of Japan).

The second type is the label of self declaration.

They either examine the whole life cycle of the product or examine the ecological performance of the product in a certain way, mainly developed by some industry associations or non-governmental organizations.

It does not emphasize testing by third party laboratories or directly audited on the spot, and some even allow manufacturers to declare themselves.

For example: Oeko-Tex Standard 100 (ECO textile standard 100), Milieukeur logo (Holland ecological symbol), Toxproof Seal (German eco textile logo), Eco-Tex (German eco textile logo), Gut (German carpet eco label), Bioland and Demeter (ECO label established by NGOs).

The third type: Declaration and reporting of environmental behavior are non selective and are buyers' criteria for buyers, but they are consistent with the standards, regulations and decrees of products sold.

For example, Clean Fashion logo and Comitextil logo.

Among so many eco textile standards and labels, Oeko-Tex Standard 100 and Europen Eco-Label are more influential in textile and clothing industry.

At the same time, we should pay attention to the ecological standard Oeko-Tex Standard 100 is voluntary, and it is not necessary to achieve its assessment index to sell in the EU market.

If it reaches its assessment index, the product can enter the more high-end circulation field, the added value of products can be improved; and the products that fail to meet their assessment criteria can not be linked to the standard and label, will enter the lower end of the circulation field, the added value of products will be much lower, of course, such products must also meet buyers' requirements to enter the EU market.

3 problems in testing eco textiles

Relative to the legislation and standardization of the technical requirements of ecological textiles, the development and standardization of the detection technology of ecological textiles are lagging behind both at home and abroad.

Although the German government proposed in 1994 to prohibit the use of azo dyes which may reduce the carcinogenic aromatic amines in textile and consumer goods, the corresponding test methods were not formally promulgated until 1998; the European Union's test method standard was released in February 24, 2004 only in the form of EU directive 2004/21/EC; while Oeko-Tex launched Oeko-Tex Standard 100, it issued a guidance document for related inspection items, namely, Oeko-Tex 200, but did not provide corresponding testing standards, and even some items were clearly informed that there was no suitable detection method.

All these bring difficulties to the implementation of relevant regulations and standards.

There are 3 main reasons for these problems:

1) the definition of eco textiles in different countries and their differences in technology and economic development level have not yet reached a unified international standard on ecological textiles.

2) the detection technology of textile ecological safety is difficult.

3) the advanced detection equipment used for testing will greatly increase the cost of detection.

4 basic safety items for textile products

4.1 formaldehyde content

Formaldehyde is a colorless, strongly irritation odorant, easily soluble in water and ethanol, usually in aqueous form.

Formaldehyde is an important organic material (aldehyde and carbonyl), widely used in the chemical industry, mainly for the plastics industry (such as phenolic resin, urea formaldehyde plastic electric jade), synthetic fiber (such as synthetic Vigny nylon polyvinyl formal), leather industry, medicine, dye and so on.

The harm of formaldehyde to health is mainly in the following aspects:

1) stimulation: the main hazard of formaldehyde is the stimulation of respiratory tract and skin mucous membrane.

Formaldehyde is a toxic substance to the protoplasm of biological cells. It binds with proteins in organisms, changes the structure of proteins and solidifies them.

Respiratory irritation and edema, eye irritation and headache were found at high concentration inhalation.

2) sensitization: direct contact with formaldehyde can cause allergic dermatitis, stain and necrosis. Inhalation of high concentration of formaldehyde can induce bronchial asthma.

3) mutagenic effect: high concentration formaldehyde is also a genotoxic substance.

Laboratory animals can cause nasopharyngeal tumors in high concentration inhalation.

Formaldehyde is characterized by headache, dizziness, fatigue, nausea, vomiting, chest distress, eye pain, sore throat, stomach difference, palpitations, insomnia, weight loss, memory impairment and autonomic nervous disorder. Prolonged inhalation of pregnant women may lead to fetal deformities or even death, and male inhalation can cause sperm deformity and death.

In order to prevent shrinkage, wrinkle and smooth appearance, the main fabric of general cellulose fiber needs to be sorted out. The use of finishing agent gradually releases formaldehyde from the wearing and using process, which is the main source of free formaldehyde. [2]

4.2 pH value test

Under normal circumstances, the pH value of human skin varies from 5.5~7.0 to slightly acidic.

This is due to the secretion of lactic acid from the sweat glands of the human body. It also makes the skin acid when sweating. Its pH value is 5.2 to 5.8. The acidic environment on the human skin surface can protect the balance of the permanent bacteria and prevent the invasion of pathogenic bacteria. Therefore, the pH value of the textiles is beneficial to the protection of the human body by [2].

However, cellulose fiber based fabrics will be treated with strong alkali solution before pretreatment, which will achieve the desired effect. This is an important reason for the unqualified results of the determination of pH value of textiles, and will also cause some harm to the human body. The most common cause of human body hypersensitivity caused by clothing is skin contact with residual alkali remaining on clothing because it has not been cleaned.

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4.3 banned azo dyes

Textile and clothing use azo dyes containing carcinogenic aromatic amines. In the long term contact with humans, dyes may be absorbed by the skin (which is more likely to occur in poor color fastness) and spread in the human body.

These dyes may decompose and restore in the human body and release some aromatic carcinogenic amines.

The metabolism of these aromatic amines in vivo makes cell deoxyribonucleic acid (DNA) change, which is the inducement of human diseases and has potential carcinogenic sensitization.

As early as 1930s, when Japanese Yoshida discovered that solvent yellow could cause liver cancer in rats, people began to realize the danger of azo dyes and their intermediates in production and use.

In fact, in 1905, the German health authorities confirmed the carcinogenic effect of some aromatic amines from dyed fuchsin, gold amine and naphthalene.

With the rapid development of dyestuff and chemical industry, this situation has further deteriorated. According to incomplete statistics, by 1960s, more than 3000 cases of bladder cancer in the world were engaged in dyestuff and chemical industry.

In 1994, the German government issued a decree prohibiting the use of 118 azo dyes capable of producing 20 kinds of harmful aromatic amines.

In 1997, the European Union issued the 67/648/EC directive, which is the European Union's ban on the use of azo dyes that can lyse and release some carcinogenic aromatic amines in textiles and leather products. There are 22 carcinogenic aromatic amines.

In March 27, 2001, the EU issued the 2001/C96E/18 directive, which further specified the textiles contained in the control area.

The directive also provides for the detection of 3 banned dyes. The detection rate of carcinogenic aromatic amines should not exceed 30 mg/kg.

In July 19, 2002, the European Union issued the order No. 2002/61, indicating that all azo dyes released from carcinogenic aromatic amines under reduction conditions were banned.

In January 6, 2003, the EU further issued directive No. third of 2003, which prohibited and sold chromic azo dyes in the EU's textile, clothing and leather products market and came into effect in June 30, 2004.

4.4 color fastness test and odor test

Analysis of Oeko-Tex 200 (test standard) detection procedures can be seen in the assessment items, in addition to color fastness and odor, other assessment items are basically toxic and harmful substances restrictions.

Why do we need to check the color fastness and smell? This is because the fastness is closely related to the two categories of assessment indicators, such as banned dyes and extractable heavy metals. When the color fastness is not good, if the banned dyes and extractable heavy metals exist, the textile will cause greater harm to the human body.

At present, the color fastness items of GB 18401 standard are water resistant (discoloration, stain), acid perspiration (discoloration, stain), alkali resistance (stain, stain), dry friction, saliva resistance (stain, stain) and so on.

The presence of odors can directly lead to a decline in the wearability of textiles. Any odors that are not related to the product or related to the products, but excessive odour indicate that there are excessive chemical residues on the textiles, which may cause potential health hazards.

At present, the odor tested by GB 18401 standard has musty flavor, high boiling oil smell, fishy smell, aromatic hydrocarbon smell and so on.