People often conveniently grabbed a plastic bag is used for holding food, but it is very harmful to human body health.Such as PVC plastics are poisonous.Although non-toxic PVC resin, but in the process of manufacturing plastic, join plasticizer toxic, add stabilizer have toxicity.So packaged food, must use special food packaging bags, must not use, in use should be paid attention to the following points:
1. PVC products when they come into contact with solvents such as ethanol ether precipitation lead salt, so alcohol is stored in the polyvinyl chloride (PVC) plastic food is not very appropriate.
2. PVC plastic in oily food, one of the lead can dissolve into food, so it is not appropriate.
3. PVC plastic temperature above 50 ℃, will slow release HCI gas, the gas is very harmful to human body health.
4. Bakelite (bakelite) and electric jade (urine aldehyde plastic) used in higher temperature, will produce harmful toxins such as free monomer, phenol, formaldehyde, urea, are unfavorable for food packaging and sheng.
5. Waste plastic recycling products, because of the complex raw material sources, unavoidably with toxic ingredients, so it should not be used as food packaging.
People's Daily use of plastic packaging is generally do not add additive, such as polyethylene, polypropylene, the use of these materials is non-toxic bags, cans, snack box and so on.
How to identify whether the toxic in the commonly used plastic products?Identification methods, such as appearance, specific gravity, boiling water method, burning method and so on, the combustion method is more simple and accurate.Now introduction is as follows:
Cut off a sample of the article, clamp, with forceps on the lighted alcohol lamp burning a lighted candles may be used (such as soft lights), and then observe the situation after burn easily, away from the fire, fire and smoke, the smell of burning phenomenon and etc., make a comprehensive judgment will know what kind of plastic.
Polyvinyl chloride (PVC) plastic, non-flammable, namely from the fire, fire and smoke to the bottom of the green, apex of yellow, fire destroyed after the pungent taste of hydrochloric acid gas.
Polyethylene plastic: combustible, from subsequent burning fire, flame and smoke color bottom top huang, when combustion has the melt drip, paraffin smells.
Polypropylene plastic: combustible, from subsequent burning fire, flame and smoke color is orange, when combustion are insoluble substance drip, has oil smell.
Polystyrene plastics, inflammable, from subsequent burning fire, flame orange smoke fly into the air at the end of the black carbon, styrene smell.
Bakelite (bakelite) : flame retardant, away from the fire, namely, the flame is yellow after burning when expansion cracks, phenol pungent taste.
Urine aldehyde plastic (jade), flame retardant, from which destroyed after fire, flame color yellow, burning when inflation has a crack, a pungent smell of urea.