Actual testing at 238 test points: Are stainless steel kitchenware products really safe?
Stainless steel water cups, lunch boxes, cookware, and tableware are kitchen utensils used daily in many households. But are stainless steel products labeled "304" or "316" truly reliable? And are products without a material label suitable for long-term food contact? In late February 2026, questions about the safety of stainless steel materials kept arising in the Toxics-Free Corps Safe Online Shopping Mutual Aid Community. To respond to consumers' actual needs, we launched the Toxics-Free Corps "Kitchen Rust Detection" public welfare testing campaign. On April 1st, we conducted professional spectral testing on 219 stainless steel samples sent by consumers nationwide or submitted offline, covering a total of 238 test points.
Figure 1: Stainless steel samples sent by consumers across China
How do we test them?
This test used XRF spectrometry for rapid elemental analysis. Considering that different parts of the same product may use different materials, such as the pot body and bottom, or the lid and wall of a cup, we performed multi-point testing on some samples. Material determination mainly referred to GB 4806.9-2023 "National Food Safety Standard - Metal Materials and Articles for Food Contact" and GB/T 20878-2024 "Stainless Steel Grades and Chemical Composition".
Figure 2: Multi-point testing samples
It should be noted that this test is mainly used to determine whether the material meets the requirements for long-term food contact, and is not used as a quantitative basis for heavy metal leaching.
Key findings
More than 40% of the test points have material risks.
Of the 238 test points, 304, 316, and pure titanium accounted for 59% combined. This means that the remaining over 40% of the test points were found to be made of materials such as high-manganese steel and materials such as 410/430, which are unsuitable for long-term food contact. In other words, not all "stainless steel" is suitable for long-term use in storing, cooking, or contacting food. There can be significant differences in corrosion resistance and food contact safety between different materials.
Figure 3: Distribution chart of points monitoring results for 238 stainless steel product
Tableware and kitchen utensils pose a higher risk
In terms of product categories, there are significant differences in safety among different stainless steel products. Water cups perform best, with nearly 90% of them made of materials suitable for long-term food contact.
In contrast, the risks of tableware and kitchenware are more prominent. Especially for kitchenware samples, more than half of the samples are made of materials that are not suitable for long-term food contact. This result deserves attention. Kitchenware and tableware come into frequent contact with food, and kitchenware is often exposed to complex usage scenarios such as high temperatures, grease, salt, and acidic ingredients, requiring higher material stability and corrosion resistance.
Figure 4: Comparison chart of test results for four types of stainless steel products
Products with clearly labeled materials are more reliable, but there are also products that are "downgraded" or counterfeited.
Of the samples submitted for testing, over half were labeled as being made of materials such as 304 or 316 stainless steel. At 129 test points with clearly labeled material specifications, 74.4% of the measured results matched the labeled specifications. This indicates that products with clear material labeling are generally more reliable.
Figure 5: Comparison chart of labeled materials of samples
However, we also discovered two types of problems. One is "material downgrading." 17% of the test points showed discrepancies between the labeled and actual measurements; for example, the labeled material was 316, but the actual material was 304. While 304 is generally suitable for long-term food contact, this can mislead consumers about the product's value. The other type is counterfeiting. 8.5% of the test points were labeled as 304 or 316, but the actual test results showed high-manganese steel or 410/430, materials unsuitable for long-term food contact.
In other words, the labeled material is not entirely equivalent to a safety guarantee, but it is still an important reference for consumers to assess risks.
Figure 6: A stainless steel lunchbox labeled as being made of 316 stainless steel was found to contain more than 9% manganese.
Products without labeled material specifications pose a significantly higher risk.
In contrast, the risks associated with products lacking material labeling are more pronounced. Of the 109 test points where no material labeling was found, over 70% were identified as using materials unsuitable for long term food contact. This data illustrates that the presence or absence of clear labeling is a crucial dividing line for ordinary consumers when assessing the risks of stainless steel products. While products with labeled materials may also be counterfeited or downgraded, the probability of encountering a problem with unlabeled products is significantly higher.
