Time put:
Recently, "PVC lasts film is poisonous " the message causes attention again on the network. The message points out, be in early 2013, CCTV " weekly quality reports " already investigated exposure " the PVC of 15 brands lasts film is contained ban change an agent with model (plasticizer) " , this kind of model changes an agent to have very great harm to human body. And when lie between 5 years, there still is the PVC of 70% to last at present on home market film.
Doubt:
Does PVC last how does velar noxiousness happen? "Poisonous " last what effect does film produce to human body health? How to discern does environmental protection last safely film? Current, what occupation standard and legal laws and regulations does the country have?
Solve:
PVC lasts film adds plasticizer
The food that does not eat at ordinary times, rip to last film laps, when putting freezer to save, can last, prevent " string together flavour " ; The booth side supermarket, street is used last cooked food of velar bag Fu and fruit vegetable, make food looks more clean and fresh. Little imagine, in this process, some last film may not rise " last " action, make instead food " toxic " .
Last at present on velar market, have PE (polyethylene) with PVC (polyvinyl chloride) last two kinds film, use at packing unripe fresh food. "PVC has good mechanical performance, be able to bear or endure chemistry is corroded it is good to reach flame retardation wait for an advantage, in plastic industry use quantity is next to PE, be the 2nd big general and plastic. " science of Nanjing university high polymer and Xue Ji of engineering department professor are being accepted " Chinese science signs up for " when the reporter is interviewed, express.
Use as keep little film and character, opposite PVC filmy tenacity and intensity differ PE film a bit, defeat easily. But PVC lasts film has what do not suit to be used at oiliness grease food to last, cannot microwave heats, cannot high temperature heats wait for use limitation.
Because PVC material hear resistance is poor, when encountering high temperature, be decomposed and release chloridize hydrogen gas, make product function drops and device is damaged, accordingly, generator joins plasticizer DEHP, DOP normally (adjacent benzene 2 formic acid 2 laborious ester) , and a few hot stabilizing agent, in order to drop treatment temperature.
In addition, PVC itself is kind of horniness stock, after joining plasticizer, can become soft, bend easily, there is wide application in the domain such as car, electric power, building materials.
Noxiousness comes from plasticizer
The expert expresses, PVC itself is avirulent, because added plasticizer, make last film arose " noxiousness " .
To assure to last film is softer, more stick, plasticizer dosage is bigger, be as high as 30%-50% in content of the plasticizer in film of soft qualitative PVC especially. And, domestic and international already some animal experiments make clear, plasticizer DEHP, DOP has liver noxiousness, can cause cancer. It is related food industry, the country such as the United States, Russia, southeast Asia, and area of and other places of Hong Kong, Taiwan is banned strictly already pack food with the PVC film that contains plasticizer. Europe in all body still is banned make children writing material with the PVC that contains plasticizer.
In recent years, come on stage as what set related the cry of consumer and country, partial PVC filmy generator alleges poisonous plasticizer is not contained in their industry production, indicate to be not contained in bag mount even " DEHP " .
Xue Ji is late to its sampling assay now, these filmy bases are polyvinyl chloride and oneself 2 acid 2 laborious ester, latter often uses as the admirable cold-resistant plasticizer of PVC, can endow with at the microtherm plasticity with good product, content is 31.7 Wt% . Small mouse experiment makes clear, its have liver noxiousness, can cause cancer. "All plasticizer are chemical product, be determined to have noxiousness. Changed new-style plasticizer, remain those who have a harm. Remain those who have a harm..
"Those who add plasticizer last film, plasticizer is very easy and migratory piece, after be being contacted with food directly, although do not heat to also be met,infiltration arrives among food, and after person edible, was equivalent to taking hormone, cause endocrinopathy, affect the growth of male reproduction system especially. " Xue Ji tells a reporter, "Will strictly tell, without PVC " last film " view, can interpret PVC film only, because it cannot use as,food is packed. Because it cannot use as,food is packed..
Because the experiment in the past is to be on the animal body such as small rat,undertake, about " plasticizer is right the person is poisonous " , home returns existence difference up to now. "Chemical product cannot have when food, this is common sense. Should prove avirulent, need does a series of strict scientific tests. But fall in avirulent without the proof circumstance, cannot use the food that pack to sell customer. " Xue Ji says.
Scientific standard and regulation urgently perfect
In occupation standard and state law code the level, at present of continue to use is former Ministry of Public Health announce at 80 time " pvc of the food things that pack shapes taste wholesome standard " , wait for Dou Moming to set truly to dosage, phyletic, suitable scope, make a part unripe factory manufacturer borrows this " got chance " . The expert suggests management department drafts scientific standard and regulation as soon as possible.
How should consumer discern last safely film? Xue Ji points out, PE lasts film does not contain plasticizer, safe environmental protection, its characteristic is colorless and transparent, coiling together is white, and PVC is filmy, monolayer film also is transparent, do not look to give facial expression, but coil together color is small yellow. The expert expresses, current, size supermarket sells PVC film early basically no longer, the person that more use is street edge small faker, they carry certain way trade price case arrives cheaper PVC is filmy, in addition, what the door curtain of partial restaurant uses also is the PVC material that contains a large number of plasticizer, some returns stimulating odour.
"Both price differs very few, proposal consumer still should go to big supermarket to buy PE to last film, do not buy the food that PVC film is packed to the side of the street as far as possible. " Xue Ji says.
Xue Ji earlies childhood, current and medical what blood transfusion bag uses also is the PVC material that contains plasticizer, what this kind of material can treat plaque in case is caky, have the effect of stable red blood cell, lengthen blood in blood transfusion bag store time, but diffuse inside blood, the meeting is right healthy influential. Many animal experiment makes clear, the meeting is right system of heart, hepatic, lung, reproduction produces undesirable effect, "This is an open to question problem really, the scientist is trying hard now the substitute with new test. The scientist is trying hard now the substitute with new test..
