Question 1: Do ordinary glasses contain lead? How to judge? How to tell if a crystal glass contains lead?
Use crystal tableware to serve food and drinks, which looks gorgeous and addictive. But many people cannot imagine that if cups made of lead-containing artificial crystal are used to hold acidic drinks such as honey, it will cause lead pollution and seriously endanger health.
Lead poisoning patients - most of them used crystal glasses
According to Professor Zhu Qishang, director of the poisoning department of West China Fourth Hospital of Sichuan University, the lead poisoning patients treated in the poisoning department of the hospital Many of the patients drank acidic drinks from crystal glass containers.
Crystal products - a threatening source of lead pollution
Relevant experts say that crystal products are a threatening source of lead pollution. The lead oxide content is often as high as 20% to 30%. If it is used to hold water, it will generally not cause lead poisoning. However, if it is used to hold wine or acidic drinks, the lead in the crystal product will be precipitated and dissolved in the wine. or in acidic drinks. Experiments show that the longer the wine is served, the higher the lead content in the wine.
Other foreign experiments have proven that if 1 liter of brandy is placed in a crystal vessel, after 5 years, the lead content in the wine can be as high as 20,000 micrograms per liter, far exceeding the environmental protection department’s requirements for drinks. The lead content in the product should be lower than the regulation of 50 micrograms/liter.
Lead poisoning - more harmful to children
The World Health Organization stipulates that if a person's blood lead level is greater than 100 micrograms/liter, it is lead poisoning. When lead accumulates in the blood to a certain extent, it will cause a decline in memory and intelligence, and lead to mental disorders, nightmares, insomnia and other problems.
Lead poisoning is more harmful to children and can easily cause mental retardation in children. Therefore, try to avoid using crystal products to store alcohol, juice or acidic drinks for a long time to avoid lead accumulation causing poisoning and harming health.
How to tell whether a crystal glass contains lead?
Appearance and feel can be distinguished
When buying crystal glass tableware, you can distinguish between glass, lead-containing crystal glass and lead-free crystal glass by sound, feel, appearance, etc.
Ordinary glass products have dull color, poor refractive index, rough workmanship, poor feel, and even bubbles in some places, and the sound is dull when tapped lightly.
Compared with ordinary glass products, crystal glass products have bright color, strong refractive index, exquisite workmanship, and good hand feel. They look like they are made of crystal and have a crisp metallic sound when tapped lightly. Lead-containing crystal glass products are slightly heavier than lead-free crystal glass products.
After adding lead, the glass looks like crystal
Glass containers circulating in the market are classified according to their materials and can be divided into ordinary glass containers and crystal glass containers.
Crystal glass containers are divided into two types: lead-free crystal glass and lead-containing crystal glass. Because the color, texture, and gloss of ordinary glass are not ideal. Adding lead to the glass can greatly increase the refractive index of the glass, making it look like it is made of crystal, so it is called crystal glass. Some ornaments of various shapes, crystal glasses, crystal lamps, etc. are made of lead. Made of glass.
There is no relevant national standard. At present, our country has not formulated a national standard for crystal glass. Since there is no national standard, many companies develop their own corporate standards for production, but most companies refer to EU standards for production.
According to EU standards, crystal glasses are divided into three types: lead-free, medium-lead and high-lead. The lead oxide content of medium-lead glasses reaches 24%; the lead oxide content of high-lead glasses reaches 36%.
If the crystal glass container is produced in accordance with EU standards, no matter what kind of product it is, there are strict international regulations on how much lead it contains, and it should be safe for the human body. However, due to the lack of standards in our country, it cannot be ruled out that individual manufacturers are very arbitrary in their production and it is difficult to guarantee product quality.
Toxic knowledge
The hazards of lead
In daily life, if cups made of lead-containing artificial crystal are used to hold alcohol, cola, When consuming acidic drinks or other acidic foods such as honey and fruit juice containing fruit acid, lead ions may form soluble lead salts and be ingested by the body along with the drinks or foods, seriously endangering health.
▲Lead mostly passes through the blood-brain barrier in the form of free state or inorganic compounds, causing harm to the central nervous system with rich blood vessels - the hippocampus and cerebral cortex.
▲When the blood lead concentration reaches 30 micrograms/liter, neurotoxic reactions such as general fatigue, dizziness, headache, anemia, memory loss, muscle and joint pain, constipation, and irregular menstruation in women will occur.
▲Symptoms such as arteriosclerosis, gastrointestinal ulcers and fundus bleeding are also related to lead pollution.
▲When the blood lead level is high, the patient has a metallic taste in the mouth, and the water in the patient's blood vessels penetrates into the brain interstitium...gt; gt;
Question 2: I would like to ask: Generally speaking, as long as it is made into glass bottles, most of them are lead-free. How to judge whether a crystal glass contains lead?
Use crystal tableware to serve food and drinks, which looks gorgeous and addictive. But many people cannot imagine that if cups made of lead-containing artificial crystal are used to hold acidic drinks such as honey, it will cause lead pollution and seriously endanger health.
Lead poisoning patients - most of them used crystal glasses
According to Professor Zhu Qishang, director of the poisoning department of West China Fourth Hospital of Sichuan University, the lead poisoning patients treated in the poisoning department of the hospital Many of the patients drank acidic drinks from crystal glass containers.
Crystal products - a threatening source of lead pollution
Relevant experts say that crystal products are a threatening source of lead pollution. The lead oxide content is often as high as 20% to 30%. If it is used to hold water, it will generally not cause lead poisoning. However, if it is used to hold wine or acidic drinks, the lead in the crystal product will be precipitated and dissolved in the wine. or in acidic drinks. Experiments show that the longer the wine is served, the higher the lead content in the wine.
Other foreign experiments have proven that if 1 liter of brandy is placed in a crystal vessel, after 5 years, the lead content in the wine can be as high as 20,000 micrograms per liter, far exceeding the environmental protection department’s requirements for drinks. The lead content in the product should be lower than the regulation of 50 micrograms/liter.
Lead poisoning - more harmful to children
The World Health Organization stipulates that if a person's blood lead level is greater than 100 micrograms/liter, it is lead poisoning. When lead accumulates in the blood to a certain extent, it will cause a decline in memory and intelligence, and lead to mental disorders, nightmares, insomnia and other problems.
Lead poisoning is more harmful to children and can easily cause mental retardation in children. Therefore, try to avoid using crystal products to store alcohol, juice or acidic drinks for a long time to avoid lead accumulation causing poisoning and harming health.
How to tell whether a crystal glass contains lead?
Appearance and feel can be distinguished
When buying crystal glass tableware, you can distinguish between glass, lead-containing crystal glass and lead-free crystal glass by sound, feel, appearance, etc.
Ordinary glass products have dull color, poor refractive index, rough workmanship, poor feel, and even bubbles in some places, and the sound is dull when tapped lightly.
Compared with ordinary glass products, crystal glass products have bright color, strong refractive index, exquisite workmanship, and good hand feel. They look like they are made of crystal, and they make a crisp metallic sound when tapped lightly. Lead-containing crystal glass products are slightly heavier than lead-free crystal glass products.
After adding lead, the glass looks like crystal
Glass containers circulating in the market are classified according to their materials and can be divided into ordinary glass containers and crystal glass containers.
Crystal glass containers are divided into two types: lead-free crystal glass and lead-containing crystal glass. Because the color, texture, and gloss of ordinary glass are not ideal.
Adding lead to the glass can greatly increase the refractive index of the glass, making it look like it is made of crystal, so it is called crystal glass. Some ornaments of various shapes, crystal glasses, crystal lamps, etc. are made of lead. Made of glass.
There is no relevant national standard. At present, our country has not formulated a national standard for crystal glass. Since there is no national standard, many companies develop their own corporate standards for production, but most companies refer to EU standards for production.
According to EU standards, crystal glasses are divided into three types: lead-free, medium-lead and high-lead. The lead oxide content of medium-lead glasses reaches 24%; the lead oxide content of high-lead glasses reaches 36%.
If the crystal glass container is produced in accordance with EU standards, no matter what kind of product it is, there are strict international regulations on how much lead it contains, and it should be safe for the human body. However, due to the lack of standards in our country, it cannot be ruled out that individual manufacturers are very arbitrary in their production and it is difficult to guarantee product quality.
Toxic knowledge
The hazards of lead
In daily life, if cups made of lead-containing artificial crystal are used to hold alcohol, cola, When consuming acidic drinks or other acidic foods such as honey and fruit juice containing fruit acid, lead ions may form soluble lead salts and be ingested by the body along with the drinks or foods, seriously endangering health.
▲Lead mostly passes through the blood-brain barrier in the form of free state or inorganic compounds, causing harm to the central nervous system with rich blood vessels - the hippocampus and cerebral cortex.
▲When the blood lead concentration reaches 30 micrograms/liter, neurotoxic reactions such as general fatigue, dizziness, headache, anemia, memory loss, muscle and joint pain, constipation, and irregular menstruation in women will occur.
▲Symptoms such as arteriosclerosis, gastrointestinal ulcers and fundus bleeding are also related to lead pollution.
▲When the blood lead level is high, there is a metallic taste in the patient's mouth, and water penetrates into the patient's blood vessels...gt;gt;
Question 3: What else is there? How many people have been deceived by the "lead-containing glass" pitfall? The material of glass mainly consists of three parts: basic raw materials, fluxes and colorants, as well as decolorizers, clarifiers and emulsifiers.
*Basic raw materials for glass production
Silica is the most important raw material for glass production. The reserves of silica on the earth are very large. Silica is the main raw material for stone and for making glass. The main raw material. The silicon content of various stones is different. These materials are the most common in our lives.
*Fluxing agent
Silica The melting point is very high, and it is very restrictive to achieve this honor. The ancients tried to find ways to add other substances to lower its melting temperature. In addition, silica melts very abruptly. There is no filtration transition stage of gradually softening during the heating process. After being fused with some other substances, the glass can enter various states of glory at different temperatures, with powerful shaping operations and effective shaping. This substance is a flux.
Fluxing agents are usually raw materials containing sodium oxide, potassium oxide, lead oxide, calcium oxide, barium oxide, etc., such as limestone, feldspar, soda ash, boric acid, lead compounds, and barium compounds. (Sodium oxide can reduce the temperature of glass. The viscosity in the formation makes the glass easy to melt and plays a good fluxing role; barium oxide plays a basic role with sodium oxide in the formation of glass; tin oxide can increase the chemical stability and mechanical strength of the glass; lead oxide It can increase density, improve snaking, and have special luster; lead can increase the refractive index of glass to light and reduce the scattering rate, making the glass more shiny and stable.
* Clarifying agent
Some bubbles will appear during the glass making process. Clarifying agents are used to reduce these bubbles. The main commonly used ones are arsenic oxide, antimony oxide and nitrate salts.
*Emulsion agent
In glass production, the artist makes the glass opaque according to the requirements of the work. What makes the glass opaque is the emulsion. It can make the glass produce crystallized or unfixed colloidal particles, which are different from the glass itself. Different refractive indexes will produce an opaque effect. Commonly used emulsions include tin oxide, antimony oxide and phosphate.
*Decolorizing agent
The first color agent is mainly used to eliminate raw materials The impurities in the glass bring undesirable colors to the glass, making the glass colorless and transparent. There are mainly two types of chemical decolorants and physical decolorizers. Chemical decolorants usually decolorize through oxidation, and the main ones are sodium nitrate. , potassium nitrate. Physical decolorizing agents make glass colorless by producing complementary colors, mainly including manganese dioxide, selenium, cobalt oxide, and bromine oxide.
Question 4: Does China’s glass industry still contain lead? Friends , please rest assured! The cost of lead glass is very high, at least several times or even dozens of times that of ordinary glass. It can only be used for high value-added products. The wholesale price of glass cups is so low that it is not enough to recover (tens of percent) silicon. The raw material price of lead acid is so high that no stupid company is willing to lose money and use a large amount of "lead glass to make cups." Therefore, please feel free to use your cup. In addition, the light transmittance of lead glass is not very high, and it is generally difficult to pass through 91 (the light transmittance of K8, K9 and other optical glasses is generally 90 to 93). In the silicate industry, lead silicate "does not belong to Additives that increase the light transmittance of glass." Although the light transmittance of lead glass is not high, it can greatly increase the refractive index of the glass, causing it to exhibit "diamond-like" refraction and dispersion phenomena, which has high ornamental value. Therefore, it is suitable for manufacturing high-priced "glass decorations, handicrafts, etc. Lead glass with a lead content greater than 30% is used for nuclear protection. The price is 400-800 yuan per kilogram, which is higher than the price of standard optical glass. So , please rest assured again.
Question 5: Everyone says that glass contains lead, but some people say it does not contain lead? Please answer 10 points. Rumors are spreading that edible glass contains lead. I think most people don’t know much about the production process of glass, so they will inevitably be fooled. Simply put, lead-containing glass belongs to special glass. Special glass not only contains lead, but also Add any other metal to form various colors. To put it bluntly, it looks good, so crystal glass contains lead. As for food-grade glass, the country has specific regulations. Common glasses are divided into soda glass, potassium glass, and lead glass. Since soda glass is made of quartz sand and sodium carbonate, it is cheap, non-toxic and harmless, so it is widely used in the food industry, construction industry and general-purpose industries. As special glasses, lead glass and potassium glass are much more expensive and are only used in special industries. Fengyang County in Chuzhou City is one of the most well-known high-quality quartz sand bases in the country. Whether it is ordinary white material, refined white material, or high white material, food bottles are all made of soda glass. The so-called refined white material mainly contains iron and copper. , manganese and other impurities are less. So don’t worry when buying glass bottles. Rumors that glass contains lead have a great impact on the sales of glass products. I believe that if more scientific knowledge is popularized and people learn to believe in science, they will avoid misunderstandings.
Question 6: What is high white material glass? Is it leaded glass? High white glass is commonly known as "ultra-white glass" or "ultra-clear glass". It is called "low-iron glass" in the profession. It is not lead glass. Lead glass is mostly used in the field of radiation protection, such as XRD. The see-through windows are made of leaded glass.
In the process of glass manufacturing, if the content of iron is too high, there will be more internal color components, so that light will be easily absorbed when it passes through the glass, resulting in a decrease in light transmittance. This is what we call low transparency.
When you cut a piece of ordinary glass, does the section appear blue-green? Similar to the lower piece of glass in this picture, and the upper part is the ultra-white glass mentioned here~
The following table lists the iron content (c) and redox degree (Redox) in ordinary glass The relationship with the light transmittance T:
It can be seen that in ordinary glass without obvious defects (nodules, bubbles, streaks, impurities, light distortion, etc.), the iron content has an impact on the light transmittance. The impact is relatively large.
Therefore, ultra-white glass is to reduce the iron content in the glass composition as much as possible (usually controlled within the range of ≤0.011), and increase the light transmittance to above 92 without obvious defects. From the surface, it looks like It gives people a crystal clear feeling.
This visual effect is a major selling point on ordinary daily necessities, and it can also increase the level of beauty when used in buildings; in special fields, high light transmittance is its biggest advantage, such as photovoltaics, solar energy, etc. Industries that require high transparency ~
Question 7: Could a glass worth more than ten yuan be a lead-containing crystal glass? A glass worth more than ten yuan is a lead-containing crystal glass.
Glass containing lead is called crystal glass. Those containing 24 lead or above are called full lead crystal, and those containing less than 24 lead are called lead crystal. The advantage of adding lead is that it is heavier, textured, more transparent, clear and bright; and the refractive index of this glass material is very high, it looks crystal clear, and has a metallic sound when struck, which is beautiful and pleasant to the ear. This kind of glass material is also more expensive and is generally used in handicrafts.
High borosilicate glass (also known as hard glass), because its linear thermal expansion coefficient is (3.3±0.1)×10-6/K, is also called "borosilicate glass 3.3". It is a special glass material with low expansion rate, high temperature resistance, high strength, high hardness, high light transmittance and high chemical stability. This material is first of all non-toxic and healthy, with good resistance to severe temperature differences and good price performance. It will not be affected by It will break when hot water or ice water is poured into it. Therefore, most manufacturers of glasses on the market claim that they use this kind of glass material. The price of this kind of material is also relatively expensive. Manufacturers that really use this kind of material such as Xino Glass Cups sell for between 200 and 500 each.
Price is the first priority. Since borosilicate glass and crystal glass are relatively expensive, ordinary glass is generally used for glasses costing more than ten yuan.
Then there is the product introduction. High-end glasses are generally manufactured by regular manufacturers. These manufacturers will definitely indicate the main ingredients of their products in their product descriptions, so that they can distinguish which are crystal glasses and which are high borosilicate glasses. .
Crystal glass can be distinguished from ordinary glass in terms of sound, feel and luster.
1. Sound, tap the body of the glass with your fingers. Because the crystal glass can make a metallic sound, it sounds more pleasant to the ear.
2. In terms of hand feel, crystal glass is thicker and heavier, which is significantly different from ordinary glass.
3. Tongue licking. Even if the crystal glass is touched with the tip of the tongue in summer, it will feel cold and cool, but not vice versa.
4. Gloss, the refractive index of crystal glass is particularly good, and it can absorb gloss. Put the glass in the sun, and it will release beautiful brilliance no matter what angle it is viewed from.