The “Invisible Red Line” on Your Tongue: Why Is the Chlorine Content in Food Packaging Films So Strictly Regulated?

Preface 

Opening snack bags to grab potato chips, using plastic bags to portion leftover food—these are all scenarios where food packaging films come into contact with food. “ Close contact ” Consumers pay attention to packaging hygiene and breathability, yet rarely notice the key indicators. —— Chlorine content. 

Chlorine content is in food packaging films. “ Hard indicator ” The country has established clear regulatory limits; any exceedance of these limits results in a failure assessment. Why is the chlorine content so strictly controlled in this thin film? What are the potential risks associated with exceeding the limit? And how can membrane manufacturers effectively control chlorine levels? This article will break down these questions and explain the underlying reasons. “ Chlorine-resistant logic ”。

I. First, let’s clarify: in food packaging films... “ Chlorine ” Where did it come from? 

The chlorine in food packaging films is not intentionally added; rather, it primarily originates from raw materials, processing aids, and residual traces from the manufacturing process. Clarify this point. “ Hiding place ” is a prerequisite for understanding the importance of chlorine control. 

(1) Raw materials provided: Chlorine-containing resin “ Innate attribute ”

Polyvinyl chloride ( PVC ) is a typical chlorine-containing raw material that was widely used in the past due to its low cost and high plasticity. However, its molecules contain a large number of chlorine atoms, which tend to be slowly released over time. Moreover, if recycled plastics are mixed in... PVC Even trace amounts of chlorine impurities can cause the finished product to exceed the chlorine limit. 

(2) Residues of Processing Aids: At the Process Stage “ Potential risk ”

Production additives may introduce chlorine elements—first, from stabilizers with insufficient purity (such as... PVC First, the calcium stearate contains chloride impurities; second, residual chlorine-based cleaning agents were not thoroughly rinsed away; third, chlorine-containing components in the printing ink may migrate into the inner layers. 

(3) Process byproducts: produced by high-temperature processing “ Accidental byproduct ”

During high-temperature processing of thin films, chlorine-containing impurities may decompose to produce chlorine-containing compounds. For example, trace amounts may be incorporated during the production of polyolefin films. PVC ， 180℃ At the above processing temperature, PVC It will release hydrogen chloride ( Hydrochloric acid ) The gas is adsorbed and remains trapped within the thin film. 

II. The Root Cause: Excessive Chlorine Levels—The Harm Goes Beyond Just This “ A little bit ”

Strictly controlling chlorine levels essentially means preventing chlorine and chlorine-containing compounds from contaminating food, thereby avoiding health risks. The risk of exceeding the standard spans the entire chain—from production all the way to consumption. 

(1) Migratory Contaminated Foods: A Direct Threat to Human Health 

Chlorine-containing components in packaging films can migrate into food. The migration rate significantly increases when the packaging comes into contact with acidic or oily foods, or when exposed to high temperatures during heating. 

• Short-term stimulus Chlorine-containing compounds irritate the digestive tract, causing symptoms such as nausea and abdominal pain; sensitive individuals experience even more pronounced reactions. 
• Long-term hazards Long-term accumulation of low-dose chlorinated compounds may affect liver and kidney function, and some of them also have potential endocrine-disrupting effects. 

(2) Compromising food quality: Affecting taste and shelf life 

Chlorine and chlorine-containing compounds can react with food ingredients, compromising quality. 

• Change the flavor The irritating odor of hydrogen chloride can contaminate food. “ Bad odor ” For example, bread may develop a sour taste. 
• Accelerated deterioration Chlorine-containing compounds oxidize vitamins and fats, making food more prone to... “ Rancid smell ” , shorten the shelf life. 

(3) Compromising Packaging Performance: Triggering a Safety Chain Reaction 

Excessive chlorine content can compromise packaging performance and indirectly lead to safety issues. 

• Corrosion film Hydrogen chloride corrodes polymer chains, causing the thin film to become brittle, damaged, and lose its protective function. 
• Affect sealing performance Chlorine-containing impurities reduce heat-sealing performance, causing packaging to leak air and liquids and accelerating food spoilage. 

(4) Violation of regulations and standards: Facing severe penalties. 

Chlorine content is a legally mandated testing item, and products exceeding the standard are considered substandard. According to the Food Safety Law, the companies involved will face penalties such as confiscation of illegal gains and fines; in cases of serious violations, their licenses will be revoked. 

III. Standards First: The National Regulations on Chlorine Content in Food Packaging Films “ Hard constraint ”

China has established a comprehensive standard system that, across multiple dimensions—from raw materials to finished products, strictly limits the chlorine content and migration levels. 

(1) Basic Standards: Clearly Defined Limit Requirements 

• GB 4806.7-2016 Core standard, passed “ Specific migration substance ” The project indirectly limits the migration of chlorides to ensure that the migrated substances are harmless. 
• GB/T 10004-2023 For composite membranes, the release of harmful substances from chlorine-containing resins must comply with... GB 4806.7 , through “ Extract ” Project chlorine control. 

(2) Specific Material Standards: Targeted Control 

To PVC For chlorine-containing materials, standard controls are stricter: 

• GB 4806.11-2016 : For food contact use PVC Resin, residual vinyl chloride monomer ≤1 mg/kg Clearly define the requirements for hydrogen chloride release. 
• Industry Consensus Food packaging is being used less. PVC , mostly PE 、 PP 、 PET Wait for chlorine-free resin alternatives. 

(3) Testing Method Standards: Ensuring Effective Implementation of Regulation 

GB/T 30794-2015 Provide technical support for the testing standards, using potentiometric titration to accurately measure chlorine and ensure that the standards are effectively implemented. 

IV. Breaking the Impasse for Membrane Companies: From Raw Materials to Finished Products “ Chlorine control across the entire chain ”

Membrane enterprises need to establish. “ Full-chain chlorine control system ” We maintain strict quality control throughout the entire process—from raw materials and production to finished-product inspection. 

(1) Raw Material Control: Starting from the Source “ Cut chlorine ”

• Preferably chlorine-free resin : Prioritize using PE 、 PP 、 PET Use chlorine-free materials whenever possible. In special cases where chlorine-containing materials are used, suppliers must be reviewed and test reports must be obtained. 
• Strictly control the purity of additives. Use chlorine-free stabilizers and cleaning agents to avoid residual risks. 
• Disable waste recycling The use of recycled plastics of unknown origin in the production of food packaging films is strictly prohibited. 

(2) Production process: Reduce “ Chlorine production ” With “ Chlorine retention ”

• Optimize the process : Controlling Extrusion Temperature (Polyolefin Film) 160-200℃ ), to prevent the decomposition of raw materials and the generation of chlorine. 
• Thoroughly clean the equipment. Use a chlorine-free cleaning agent, followed by rinsing with purified water and drying with hot air to ensure no residue remains. 
• Need to reduce in production “ Chlorine production ” With “ Chlorine retention ”：
• Ensure proper workshop protection. Avoid the spread of chlorine-containing substances in the workshop and prevent the film from adsorbing chlorine-containing gases. 
• Finished product inspection is “ Factory seal ”：
• Batch-by-batch testing Use standard methods to measure chlorine content in the sample and ensure it meets the required standards. 
• Simulated Migration Test : Detect the migration of chlorine-containing compounds into acidic and oily food simulants to ensure safe use. 

V. Consumer Notice: 3 Avoid the招. “ High-chlorine packaging film ”

Consumers can through 3 Avoid the招. “ High-chlorine packaging film ”：

• Check the label. : Be sure to recognize “ For food contact “GB 4806.7” Mark, avoid “ Three Nothings ” Product. 
• Smell the odor Refuse packaging films with pungent or irritating odors, such as those with a sour smell. Qualified products should be odorless or have only a slight, faint plastic-like odor. 
• Select material : Priority PE 、 PP 、 PET Material—avoid direct contact with food entering the mouth. PVC Packaging. 

Conclusion 

Chlorine control in food packaging film is a safeguard for food safety on your tongue. “ Last Line of Defense ” Although this thin film may seem unremarkable, it allows for absolutely no carelessness. 

For membrane manufacturers, controlling chlorine levels is both a regulatory compliance baseline and a competitive edge; for regulators, it’s a key component of risk prevention; and for consumers, learning to identify safe packaging films is a vital safeguard for their health. 

With technological advancements, chlorine-free materials will see wider adoption, and chlorine-control processes will become more precise. As a result, the safety guarantees for food packaging films will continue to improve, allowing consumers to eat with peace of mind. 

What are some handy tips for choosing food packaging film? Feel free to share them in the comments!