Acid Gas Buildup in Archives: Managing Storage Air with Molecular Filtration

Many archive and museum storage managers have encountered a puzzling situation: the temperature and humidity recorder shows stable readings, the shelving looks fine, yet when collections are inspected years later, paper has still yellowed and turned brittle, and ink has begun to bleed. The problem is often not temperature or humidity, but the air itself — storage rooms are relatively enclosed spaces, and paper, leather, and wooden fittings release acidic gases (such as acetic acid, formic acid, and sulfur dioxide) over long periods. These molecular-level pollutants accumulate continuously in the enclosed environment, and once adsorbed by paper fibers, they accelerate hydrolysis and oxidation — a process that is slow, silent, and irreversible.

Why Traditional Methods Fall Short

The conventional response is ventilation or placing activated carbon packs. The problem with ventilation is that outside air temperature and humidity often do not match storage requirements, and frequent air exchange disrupts the hard-won microenvironment stability. Ordinary activated carbon, meanwhile, has limited adsorption selectivity for acidic gases; once saturated, it not only loses effectiveness but can become a secondary release source. For precious archives and artifacts, what is needed is continuous, targeted air purification that does not disturb temperature and humidity.

A Three-Layer Approach to Storage Air Management

A complete storage air management approach usually involves three layers:

1. Perception — real-time monitoring of temperature, humidity, and air quality changes, so managers know when problems occur.
2. Filtration — using filter media targeted at acidic molecules to continuously adsorb gaseous pollutants, rather than waiting for contamination to accumulate.
3. Systematic Control — integrating acid removal with climate control into a long-term solution, rather than adding equipment piecemeal.

Acipur’s product line is built on this logic:

• BF-10A Smart Environment Perception Controller handles the first layer — continuously collecting storage environment data, turning air problems from “discovered after the fact” into “visible in real time.”
• Molecular Acid-Removal Ion Filter (H12 HEPA) handles the second layer — adsorbing gaseous acidic molecules with H12-grade particulate interception. As a consumable, its periodic replacement is key to long-term system effectiveness.
• CJS-HP100B Heritage Climate Preservation & Acid-Removal System integrates acid removal and climate control for facilities that need a complete solution.
• TK600A Archive Dust Removal & Purification Station serves the pre-intake dust removal and purification stage, reducing external pollutants brought into storage.

It is worth noting that acid-removal filters are consumables, and their effectiveness depends on periodic replacement. The specific replacement cycle should be evaluated against actual storage area, pollution concentration, and usage duration — we recommend an environmental assessment before finalizing configuration. We do not exaggerate the role of any single device — storage protection is a systematic project, and equipment is only one part of it.

If your storage facility is facing acid gas accumulation or paper embrittlement, or if you would like to first evaluate the air quality of your current environment, we welcome you to reach out.