The current standard, GB/T 35795-2017, has been in effect for over eight years. Its shortcomings have become increasingly apparent, particularly regarding inadequate benchmarks for biodegradability, which failed to effectively block the proliferation of fake biodegradable products.
The new national standard, GB/T 35795-2026-set to take effect on April 1, 2027-introduces three core changes:
First, it improves product labeling and management. It mandates that biodegradability must comply with the GB/T 41010 standard. By requiring standardized testing, it closes the loopholes exploited by "pseudo-biodegradable" products and makes it easier to quickly identify compliant, authentic items.
Second-and perhaps most importantly-it tightens the requirements for water vapor transmission rates. There is a significant difference between the old and new standards. To put it simply: the water vapor transmission rate measures how many grams of water vapor pass through one square meter of mulch film over a 24-hour period. A lower value indicates better moisture retention, while a higher value means soil moisture is lost more rapidly.
While the old standard used broad categories, the new version introduces four distinct tiers: Tier A (≤400), Tier B (≤600), Tier C (≤800), and Tier D (>800). The Tier A category (≤400) offers the highest moisture retention, making it ideal for arid regions in the north. Conversely, tiers with higher transmission rates (800 and above) are better suited for the rainy south, helping to prevent excessive humidity under the film that could lead to root rot.
Third, the product classification system has been updated. Products are now categorized based on their "effective service life" (determined by their resistance to aging). A new category for short-term use-covering growth periods of less than 30 days-has been added to better align with the diverse cultivation cycles of various crops across the country.
Additionally, the new standard introduces limits on "substances of high concern" and revises specifications for mechanical properties, light transmission, and aging resistance.
By significantly raising the technical threshold for the industry, this new standard should leave no place for "pseudo-biodegradable" mulch films to hide!
