In our daily lives, plastic bottles can be seen everywhere. I wonder if you have noticed that there is a numerical logo shaped like a triangle symbol at the bottom of most plastic bottles (cups).
for example:
Mineral water bottles, marked 1 on the bottom;
Plastic heat-resistant cups for making tea, marked 5 on the bottom;
Bowls of instant noodles and fast food boxes, the bottom indicates 6;
…
As everyone knows, the labels on the bottom of these plastic bottles have profound meanings, containing the “toxicity code” of plastic bottles and representing the scope of use of the corresponding plastic products.
“The numbers and codes on the bottom of the bottle” are part of the plastic product identification stipulated in national standards:
The recycling triangle symbol on the bottom of a plastic bottle indicates recyclability, and the numbers 1-7 indicate the type of resin used in the plastic, making it simple and easy to identify common plastic materials.
“1″ PET – polyethylene terephthalate
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This material is heat-resistant to 70°C and is only suitable for holding warm or frozen drinks. It is easily deformed when filled with high-temperature liquids or heated, and substances harmful to the human body may dissolve out; generally mineral water bottles and carbonated drink bottles are made of this material.
Therefore, it is generally recommended to throw away beverage bottles after use, do not reuse them, or use them as storage containers to hold other items.
“2″ HDPE – high density polyethylene
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This material can withstand high temperatures of 110°C and is often used to make white medicine bottles, cleaning supplies, and plastic containers for bath products. Most of the plastic bags currently used in supermarkets to hold food are also made of this material.
This type of container is not easy to clean. If the cleaning is not thorough, the original substances will remain and it is not recommended to be recycled.
“3″ PVC – polyvinyl chloride
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This material can withstand high temperatures of 81°C, has excellent plasticity, and is cheap. It is easy to produce harmful substances at high temperatures and is even released during the manufacturing process. When toxic substances enter the human body with food, they may cause breast cancer, birth defects in newborns and other diseases. .
At present, this material is commonly used in raincoats, building materials, plastic films, plastic boxes, etc., and is rarely used for packaging food. If it is used, be sure not to let it get heated.
“4″ LDPE – low density polyethylene
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This type of material does not have strong heat resistance and is mostly used in the production of cling film and plastic film.
Generally speaking, qualified PE cling film will melt when the temperature exceeds 110°C, leaving some plastic preparations that cannot be decomposed by the human body. Moreover, when food is wrapped in cling film and heated, the oil in the food will easily melt into the cling film. harmful substances are dissolved.
Therefore, it is recommended that food wrapped in plastic wrap should be removed before putting it in the microwave oven.
“5″ PP – polypropylene
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This material, usually used to make lunch boxes, can withstand high temperatures of 130°C and has poor transparency. It is the only plastic box that can be placed in a microwave oven and can be reused after thorough cleaning.
However, it should be noted that some lunch boxes have a “5″ mark on the bottom, but a “6″ mark on the lid. In this case, it is recommended that the lid be removed when the lunch box is placed in the microwave oven, and not together with the box body. Place in microwave.
“6″ PS——Polystyrene
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This type of material can withstand heat of 70-90 degrees and has good transparency, but it cannot be placed in a microwave oven to avoid the release of chemicals due to excessive temperature; and holding hot drinks will produce toxins and release styrene when burned. It is often used in manufacturing Material for bowl-type instant noodle boxes and foam fast food boxes.
Therefore, it is recommended to avoid using fast food boxes to pack hot food, nor to use them to hold strong acids (such as orange juice) or strong alkaline substances, because they will decompose polystyrene that is not good for the human body and can easily cause cancer.
“7”Others – PC and other plastic codes
Is the plastic cup you drink from poisonous? Just take a look at the numbers at the bottom and find out!
This is a material that is widely used, especially in the manufacture of baby bottles, space cups, etc. However, it has been controversial in recent years because it contains bisphenol A; therefore, be careful and pay special attention when using this plastic container.
So, after understanding the respective meanings of these plastic labels, how to crack the “toxicity code” of plastics?
4 toxicity detection methods
(1) Sensory testing
Non-toxic plastic bags are milky white, translucent, or colorless and transparent, flexible, smooth to the touch, and appear to have wax on the surface; toxic plastic bags are turbid or light yellow in color and feel sticky.
(2) Jitter detection
Grab one end of the plastic bag and shake it vigorously. If it makes a crisp sound, it is not poisonous; if it makes a dull sound, it is poisonous.
(3) Water testing
Place the plastic bag in the water and press it to the bottom. The non-toxic plastic bag has a small specific gravity and can float to the surface. The toxic plastic bag has a large specific gravity and will sink.
(4) Fire detection
Non-toxic polyethylene plastic bags are flammable, with blue flames and yellow tops. When burning, they drip like candle tears, smell of paraffin, and produce less smoke. Toxic polyvinyl chloride plastic bags are not flammable and will extinguish as soon as they are removed from the fire. It is yellow with a green bottom, can become stringy when softened, and has a pungent smell of hydrochloric acid.
Post time: Nov-09-2023