What Tests Should Be Conducted on Packaging Paper (Part 2)

We all commonly use paper and cardboard in our daily lives—so, how do we tell the two apart? In general terms, cardboard and paper share the same structure and filler materials, but the key difference between them usually lies in their **thickness and rigidity**. Quantitative And Thickness To distinguish.

Generally, Quantitative amount exceeds 200 g m ² "Materials thicker than 0.5 mm are referred to as cardboard." Today, we're going to talk about the common types of tests performed on a particular packaging material. Paper (food packaging paper).

Food packaging paper is a packaging product primarily made from pulp and cardboard, designed to meet stringent requirements such as being non-toxic, oil-resistant, waterproof, moisture-proof, and fully sealable—while also complying with food safety standards for packaging food items. Because food packaging paper comes into direct contact with food, and most of the products it wraps are intended for consumption, its most fundamental requirement is adherence to food hygiene regulations. Additionally, depending on the specific needs of the food packaging application, it must also satisfy relevant technical standards.

1. Sensory Requirements

Sensory evaluation uses one's own sensory organs as the testing method to assess and determine the quality characteristics of paper.

Xiaomin on Testing: Use sensory checks to determine whether the paper’s color is normal, and to look for any unusual odors, mold spots, or other contaminants. Also, observe whether there’s any discoloration or lingering strange smells after soaking.

2, Lead Content

Since lead is a relatively common heavy metal found in food and packaging materials, the lead content must be tested according to standard requirements.

Xiaomin Talks Testing: This test determines whether heavy metal lead has been added to the raw materials of the paper (food-contact paper) during production, and whether the lead content exceeds the relevant standards. If the residual lead content exceeds 3.0 mg/kg, the item is deemed non-compliant.

3, Arsenic content

Because paper containing arsenic becomes more durable, but excessive arsenic can be harmful to the body, the arsenic content should be tested according to standard requirements.

Xiaomin Talks Testing: This test determines whether heavy metal arsenic was added to the raw materials used in the production of the paper (food-contact paper), and whether the arsenic content exceeds the relevant standards. If the residual arsenic level exceeds 1.0 mg/kg, the product is deemed non-compliant.

4. Formaldehyde

Formaldehyde testing refers to the quantitative analysis of formaldehyde content in paper using specific methods or instruments.

Xiaomin Talks Testing: This test can determine whether the paper poses any health risks to humans. Low-quality paper contains harmful substances like formaldehyde, and if used as food-contact paper, it can negatively impact human health.

5, Fluorescent material

Under the excitation of sufficiently strong light, electrons in a material can enter an excited state, after which they transition back to the ground state, emitting fluorescent light of a specific wavelength.

Xiaomin Talks Testing "This test determines whether the raw materials of the paper (food-contact paper) contain fluorescent substances." Fluorescent substances have low toxicity. If accidentally leaked and inadvertently inhaled or touched by the human body, they can cause health issues such as nausea, dizziness, paralysis, or even loss of consciousness. 。

6. Total Migration Amount

The total migration test involves simulating the contact between food and packaging materials, allowing migratable substances from the packaging to transfer into a food simulant. The total amount of these migrants is then determined through an evaporation-drying-weighing process.

Xiaomin Talks Testing ： Because the inner layer of the paper (food-contact paper) sometimes contains a plastic coating. To prevent leakage when holding liquids or to avoid the paper cup becoming softened due to soaking, it's important to note that during contact with beverages, small molecules from the plastic film may migrate outward into the food, potentially affecting the consumer's health. If the total migration of these substances exceeds 10 mg/d㎡ in the sample, the product will be deemed non-compliant.

7, Potassium permanganate

The potassium permanganate consumption refers to the amount of substances in the paper that can be oxidized by potassium permanganate when the paper is immersed in a solution. Most of the substances oxidized by potassium permanganate are organic compounds that have migrated from the paper, including polymer monomers, olefins, and other similar materials.

Xiaomin Talks Testing: This test determines whether the paper contains soluble organic substances (such as polymer olefins, dimers, trimers, and other low-molecular-weight polymers). Since these soluble organic compounds can enter the human body through liquids and potentially pose health risks to consumers, China has established strict regulatory limits for food-contact materials, stipulating that their concentration must not exceed 10 mg/kg.

8, Heavy metals (expressed as Pb)

Heavy metals pose certain risks to human health and the environment, which is why paper products intended for food contact (food contact paper) are required to undergo testing for heavy metals—measured as lead (Pb).

Xiaomin on Testing: This test helps determine the suitability of paper for food contact applications. Whether it contains excessive heavy metals, the requirement is that they must not exceed 1 mg/kg.

9, Microorganisms

Microbial testing is a method that applies microbiological principles and techniques to examine the types, quantities, and characteristics of microorganisms present in paper, as well as their potential impact on human health, in order to determine whether the paper meets quality standards.

Xiaomin Talks Testing This test can determine the properties of food-contact paper. Colony count testing, coliform testing, mold testing, and pathogen detection (including Shigella testing, Salmonella testing, and Staphylococcus aureus testing), among others. 。

Letter Soliciting Comments on the National Standard "Transport Packaging – Reusable Plastic Containers – Part 1: General Design Requirements"

What Tests Are Conducted on Packaging Paper? (Part 1)

Letter Soliciting Comments on the National Standard "Transport Packaging – Reusable Plastic Containers – Part 1: General Design Requirements"

What Tests Are Conducted on Packaging Paper? (Part 1)

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