Which Chemicals need ducting or filtering?

When you design or operate chemical extraction units—including ducted fume hoods, filtered enclosures, or ventilation cabinets—you need to know which chemicals to duct and which to filter. This decision depends on several key factors: the chemical’s toxicity, volatility, and hazard classification.

To help you navigate this, we’ve outlined a clear, actionable guide. It shows you which substances require external ducting and which ones you can safely filter—as long as you use the right equipment and filters.

Duct These Chemicals Using External Exhaust Systems

You should duct the following chemicals because filtration alone cannot ensure safety. These substances often carry extreme health risks or may damage your equipment if not handled properly.

1. Volatile Organic Compounds (VOCs)

• Examples: Acetone, Toluene, Xylene, Benzene

• Why duct them? VOCs evaporate quickly and produce toxic fumes. Relying on filters isn’t enough—external ducting offers a safer, more reliable solution.

2. Carcinogens and Mutagens

• Examples: Formaldehyde, Benzene, Ethylene Oxide

• Why duct them? These chemicals can cause cancer or genetic mutations with prolonged exposure. To reduce risk, always route them outside through a ducted system.

3. Corrosive or Acidic Vapors

• Examples: Hydrochloric Acid, Nitric Acid, Sulfuric Acid

• Why duct them? These vapors not only pose inhalation risks but can also corrode internal components. Therefore, ducting prevents long-term equipment damage and health issues.

4. Highly Toxic Gases

• Examples: Hydrogen Sulphide, Ammonia, Chlorine, Phosgene

• Why duct them? Even at low concentrations, these gases are dangerous. Consequently, external ducting provides the most dependable form of protection.

5. Nanoparticles and Biological Agents

• Examples: Engineered Nanomaterials, Viruses, Bacterial Spores

• Why duct them? These microscopic particles require HEPA-grade filtration or containment enclosures. Because they can bypass standard filters, you must handle them with advanced extraction setups.

For handling such hazardous substances, consider BenchVent’s BV660H-D Ducted Fume Extraction Cabinet, designed to capture and expel harmful contaminants effectively.

Filter These Chemicals with the Correct Filters

While some chemicals pose serious risks, others are safe to filter—provided that you choose the right filter type. Always match your filter media to the chemical’s properties.

1. Solvent Vapors (Non-Carcinogenic)

• Examples: Ethanol, Isopropanol

• Use: Activated Carbon Filter

• Why filter them? These solvents are common and typically low-risk. When used in small amounts, you can filter them effectively with activated carbon.

2. Particulate Matter (Non-Pathogenic)

• Examples: Lab Powders, Dust

• Use: HEPA Filter

• Why filter them? These materials don’t pose biological hazards. Therefore, HEPA filters provide a practical and effective solution.

3. Mild Acids or Bases (Low Concentration)

• Examples: Diluted Acetic Acid, Sodium Hydroxide Mist

• Use: Neutralizing Carbon Filters (Acid/Base)

• Why filter them? At low concentrations, these substances present minimal risk. Specialized carbon filters neutralize them safely and efficiently.

For applications involving such substances, BenchVent offers the BV930H-D Hood Mounted Ducted LEV Unit with Light, providing effective filtration and illumination for precision work.

❌ Never Rely on Filters Alone for These Substances

Some chemicals are simply too dangerous to filter. In these cases, filtration is not enough—no matter the filter quality.

Avoid using filters alone when handling:

• Highly toxic gases (e.g., cyanide compounds, phosgene)

• Pyrophoric or highly reactive substances

• Carcinogenic vapors in high concentrations

Instead, always choose ducted systems for maximum protection.

Get the Right Extraction System for Your Application

Choosing the right extraction method can feel overwhelming, especially with so many chemical variables. That’s where Benchvent comes in.

We work closely with customers to match their chemicals to the safest and most effective extraction solution.

Here’s how we help:

1. Contact us to receive a free chemical compatibility form.

2. Fill in your list of chemicals and include the relevant MSDS (Material Safety Data Sheets).

3. Our in-house chemical engineer will review the data and recommend the best extraction unit for your application.

Don’t Leave Chemical Safety to Chance

Every chemical setup is different, and the risks vary. That’s why we personalise every recommendation—to ensure your team stays safe and your equipment performs flawlessly.

[Reach out to Benchvent now] and take the first step toward safer chemical handling.