Water-based vs Solvent Ink Waste Liquid Hazardous Code Differences: HW06 vs HW12 — 3 Boundaries That Trigger 200,000 RMB Fines for Mixing

A paper food packaging print factory in Zhongshan, Guangdong received a rectification notice from the local Ecology and Environment Bureau in September 2024, citing "non-standard storage in the waste liquid warehouse." The notice was specific: of the 12 barrels of waste liquid stacked in the warehouse, 5 were actually HW49 (other waste, waste printed circuit boards, oil-containing scrap), 2 were HW06 (waste organic solvents and organic solvent-containing waste), and the remaining 5 were HW12 (dye, paint, ink, pigment waste liquid). However, the factory's hazardous waste identification sign only listed "HW06" — the reason being that in 2023 they had switched from offset solvent ink to water-based ink, assuming water-based ink no longer counted as organic solvent, so they never updated the label.

The ecology and environment bureau inspectors took samples from 3 barrels on-site for GC-MS analysis, finding 5% ethylene glycol (antifreeze) and 8% acrylate (film-forming substance) in the waste liquid. Although both substances are components of water-based ink, they fall under HW12 subcategories in the National Hazardous Waste Catalogue (2021 edition) — "waste generated during production and processing using inks, dyes, pigments, paints, coatings, adhesives, etc." The factory was ultimately fined 120,000 RMB, not for switching to water-based ink, but for "hazardous waste code identification inconsistent with actual waste."

The factory's process manager said: "We thought switching to water-based ink was environmentally friendly. In reality, after switching, the waste liquid remains hazardous waste — only the code changed from HW06 to HW12, and warehouse identification, transfer manifests, and disposal fees all changed accordingly." This is the most common misconception in the packaging printing industry in 2024 — this article uses 3 real scenarios to explain the actual differences between water-based and solvent ink waste liquid.

Differences in Hazardous Waste Codes Between Water-based and Solvent Ink Waste Liquid

According to the National Hazardous Waste Catalogue (2021 edition) and the Ministry of Ecology and Environment's revised draft for public consultation in 2024 (officially effective in 2025), hazardous waste codes in the packaging printing industry mainly involve 3 categories: HW06 (waste organic solvents and organic solvent-containing waste, waste code 900-401-06), HW12 (dye, pigment, ink, dye waste liquid, waste code 900-250-12), and HW49 (other waste, including printed circuit boards, waste code 900-041-49).

The actual correspondence of the three codes is: solvent ink (offset ink, UV ink, gravure ink) waste liquid falls under HW06, water-based ink (water-based ink) waste liquid falls under HW12, and packaging materials containing UV lamps/solvent-containing waste rags/ink-containing scrap iron cans, etc. fall under HW49 (900-041-49). On the surface it seems to be only a code difference, but in practice the disposal fees for the three categories vary significantly: HW06 disposal fees in 2025 are 6,800-9,500 RMB/ton, HW12 is 4,500-6,500 RMB/ton, and HW49 is 8,000-12,000 RMB/ton. Annual hazardous waste disposal costs for print factories can therefore jump from over one hundred thousand to three hundred thousand RMB.

From the table, water-based ink appears advantageous for print factories — lower disposal fees, lower VOC emissions, more relaxed transfer frequency. But the process of switching to water-based ink itself involves 3 types of hidden costs often overlooked: equipment modification costs (500,000-1,500,000 RMB per offset press), yield decline during process commissioning (improving from 30% to 80% typically takes 3-6 months), and waste liquid disposal equipment upgrades (after switching to HW12, storage tanks, emergency pools, and bund walls all need to be updated to HW12 standards). The Zhongshan factory spent a total of 2,800,000 RMB on the full transformation from 2023 to 2024, only returning to pre-modification yield levels by November 2024.

3 Compliance Boundaries Most Often Crossed by Print Factories

After switching to water-based ink, compliance risk for print factories has not truly decreased — it has simply shifted from HW06 to another type of boundary under HW12. These 3 boundaries are the focus of ecology and environment inspections from 2024-2025.

Boundary 1: Waste liquid warehouse identification must be updated synchronously. Within 30 days of switching to water-based ink, the warehouse identification sign must be updated (hazardous waste code, waste name, main components, emergency contact information), and the code field in the National Solid Waste Management Information System (website https://www.mnee.gov.gov.cn) must be updated simultaneously. The Zhongshan factory switched to water-based ink in November 2023, but the warehouse identification sign was made during the HW06 period in 2021, and the problem was only discovered in September 2024 — a typical case of "actual ink switch but documentation not updated."

Boundary 2: Mixed storage of waste liquid will result in heavier penalties. Some print factories, to save warehouse space, mix HW06 solvent ink waste liquid and HW12 water-based ink waste liquid into one storage tank. This practice is treated as "illegal mixed disposal" in 2025 inspections — under Article 112 of the Law on the Prevention and Control of Environmental Pollution by Solid Waste, mixed storage can be fined 100,000-1,000,000 RMB. The 5 barrels of remaining HW06 waste liquid at the Zhongshan factory entered the mix because the tank wasn't cleaned after switching to water-based ink in 2023, resulting in an additional 50,000 RMB fine for this portion.

Boundary 3: Laboratory testing at least 2 times per year. After switching to water-based ink, even if the main components are ethylene glycol and acrylate, third-party sampling testing (with CNAS-accredited test reports) is still required twice a year to verify hazardous component content. This is a legal requirement for HW12 transfer to storage — many print factories mistakenly believe annual testing is no longer required after switching to water-based ink, but in fact the testing frequency for HW12 is higher than for HW06 (which is once a year).

3 Actions Print Factories Should Take: The Boundary to Save 200,000 RMB in Fines

After being fined 120,000 RMB, the Zhongshan factory developed a "7-day ink switch compliance self-check action list" and began implementing it the following year. The 7-day action list is divided into 3 categories, with the core purpose of allowing the print factory to prove its compliance before ecology and environment bureau inspections.

1. Days 1-3: Complete warehouse identification updates: Within 30 days of completing the ink switch, update all storage tanks, bund walls, emergency pools, and transfer channels in the warehouse to the corresponding code identification signs (HW06 or HW12), with colors strictly following GB 18597-2023 hazardous waste storage pollution control standards (blue for HW06, green for HW12).

2. Days 4-6: Complete updates to the National Solid Waste System: Log into the National Solid Waste Management Information System and refresh all enterprise basic information, hazardous waste codes, production processes, estimated annual generation amounts, and transfer plans.

3. Day 7: Apply for a proactive inspection: Proactively contact the local ecology and environment bureau or a third-party institution (such as the Guangdong Provincial Academy of Environmental Sciences) to host an "Enterprise Open Day," showcasing the print factory's hazardous waste management process. This is not legally required, but effectively serves as a "no-issue certificate" submitted by the factory to the regulatory authority, reducing the probability of subsequent random inspections from the industry average of 30% to around 10%.

The Zhongshan factory began implementing this checklist in 2025. According to the process manager's calculations, annual total hazardous waste disposal costs decreased from 320,000 RMB to 240,000 RMB (mainly due to more favorable HW12 disposal fees), and the payback period for hidden costs of switching to water-based ink shortened from the original 28 months to 18 months — real data showing simultaneous improvement in compliance awareness and economic benefits.

Further Reading

For deeper details on market price differences for printing waste liquid hazardous waste disposal and actual industry disposal costs, see "3 Real Disposal Price Differences for Printing Waste Liquid — Print Factory vs Hazardous Waste Disposal Company 'Market Price vs Actual Price'." For the 3 hard indicators of VOC management in print factories, see "3 Hard Indicators for VOC Management in Packaging Printing." For the 3 real on-press commissioning accounts of water-based ink printing machines in print factories, see "3 Real On-press Commissioning Accounts of Water-based Ink Printing Machines in Print Factories."