How to Handle Nafion Dispersion Safely in the Lab

Nafion dispersion is the liquid form of a perfluorosulfonic acid (PFSA) ionomer. Labs use it to make catalyst inks for PEM fuel cells and electrolyzers, to cast thin membranes and to coat sensors. The polymer itself is stable, but most of the bottle is solvent, and that is where the risk sits.

This guide walks through each stage, from the day a bottle arrives to the day you dispose of the last drop. It is written for researchers who stock fuel cell materials for research and want one protocol their whole group can follow. Knowing how to handle Nafion dispersion safely protects your data as well as your people: solvent loss and contamination shift ink viscosity and ionomer content, which later shows up as weak or uneven electrodes.

What is in a Nafion dispersion and why it needs care

A Nafion dispersion is PFSA polymer suspended in a water and alcohol mixture. In the 5 % grade, alcohol makes up about half of the bottle. According to Chemours Product Bulletin P-14, the main grades break down like this:

Property (Chemours P-14)	D520 / D521 (5 %)	D2020 / D2021 (20 %)
Polymer content, wt %	5.0–5.4	20.0–22.0
Water, wt %	45 ± 3	34 ± 2
1-Propanol, wt %	48 ± 3	44 ± 2
Ethanol, wt %	< 4	< 2
Viscosity at 25 °C, cP	10–40	50–500

 

Two facts follow from this table. First, the hazard is mainly the solvent. 1-Propanol is a flammable liquid with a flash point of about 15 °C, so vapour can ignite at room temperature. Second, the polymer is acidic and hydrophilic. Walther Grot, the inventor of Nafion, notes in Fluorinated Ionomers that PFSAs behave very differently from PTFE: they absorb water, pick up contaminants and carry acid groups, even though skin contact with the solid polymer is considered low risk.

If you are still choosing between membrane grades rather than dispersions, compare Nafion membrane grades first.

Before you open the bottle

Read the SDS and the handling bulletin

Chemours asks users to review three documents before handling: the Safety Data Sheet (SDS) for the exact grade, its technical bulletin T-01 "Safety in Handling and Use", and the fluoropolymer industry guide to safe handling. Keep the SDS where the dispersion is used, not in a shared drive nobody opens.

Check the cap and store the bottle upright

Alcohol-based dispersions can weaken cap seals if the liquid sits against the lid for long periods. Stand bottles upright as soon as the shipment arrives, check for residue around the cap, and label the receiving date next to the packaging date.

PPE and ventilation for Nafion dispersion

Ventilation comes first. Chemours states that ventilation should be provided whenever the dispersion is handled, and that more local exhaust is needed when you process it at higher temperatures or in larger amounts.

• Fume hood or local exhaust for opening, pouring, mixing, spraying and drying.
• Safety glasses or goggles, because the solvent and the acidic polymer both irritate eyes.
• Chemical-resistant gloves of the material named in the SDS, plus a lab coat.
• No ignition sources nearby: hot plates, open flames and non-rated equipment stay out of the hood while solvent is exposed.
• Grounding and bonding: Chemours advises grounding both the supply and the receiving container before you dispense a dispersion that contains flammable solvent.

Dispensing and mixing catalyst ink step by step

Most exposure happens while you pour and mix. Follow this order every time:

1. Mix the dispersion inside its original container before use, by stirring or gentle rolling, as Chemours recommends.
2. Dispense through a 10 µm filter to catch gel particles.
3. Pour only what you need into a clean, labelled container and recap the stock bottle at once to limit air exposure.
4. Add solvents and catalyst inside the hood. Keep the vial capped during sonication and use a cooling bath, because sonication warms the ink and drives off alcohol vapour.
5. Label every working vial with the grade, concentration, date and your initials so nobody mistakes it for a plain alcohol solution.
6. Wipe drips with an absorbent pad and place it in the solvent waste container, not the open bin.

Ink recipes, ionomer-to-carbon ratios and catalyst choice are outside the scope of this safety guide. For those, see our Pt/C catalyst selection guide.

Nafion dispersion storage and shelf life

Store the dispersion so that neither the solvent nor the polymer changes. Chemours recommends:

• Sealed glass, plastic or stainless-steel containers only, ideally the original bottle.
• A temperature between 0 °C and 32 °C (32–90 °F), in a dry, temperature-controlled room away from direct sunlight.
• Never freeze the dispersion.
• A flammables cabinet if your institution requires one for alcohol solutions.

Under these conditions Chemours expects a shelf life of two years from the packaging date printed on the label. Use the oldest bottle first and record when each one is opened.

Spills and exposure

For a small spill inside a hood, remove ignition sources, absorb the liquid with an inert pad and bag it as solvent waste. For a spill outside the hood, ventilate the area and follow your lab’s spill procedure. For skin or eye contact, use the first-aid steps in the SDS for your grade and report the incident to your safety officer. Keep a spill kit with absorbent pads, a sealable bag and spare gloves next to the hood where dispersion is used.

Waste and disposal

Collect used and expired dispersion as flammable solvent waste in a closed, labelled container. Chemours states that treatment, storage, transport and disposal must follow federal, state or provincial, and local rules. Because PFSA is a fluoropolymer, ask your EHS office whether your institution handles it as PFAS or fluoropolymer waste.

One-page safe-handling checklist

#	Check before you start
1	SDS for this exact grade is printed and next to the hood
2	Bottle is upright, sealed and within two years of its packaging date
3	Fume hood or local exhaust is on and working
4	Goggles, chemical-resistant gloves and lab coat are on
5	No open flames, hot plates or sparks near the work area
6	Supply and receiving metal containers are grounded
7	10 µm filter and labelled receiving container are ready
8	Closed solvent waste container and spill pads are within reach

 

Need PFSA dispersion with the SDS in the box? Canrd supplies ionomer dispersions and other fuel cell research materials in lab-sized quantities. Tell us your application and target concentration and email our lab team for a quote.

 

Once your ink is ready, the next step is the test cell. Our MEA test fixture setup guide covers assembly and break-in.

Frequently asked questions

Is Nafion dispersion flammable?

Yes. The 5 % and 20 % grades contain roughly 44–48 % 1-propanol, which has a flash point near 15 °C. Keep ignition sources away and ground containers when you pour.

Do I need a fume hood to use Nafion dispersion?

Chemours recommends ventilation for all handling and more local exhaust when you heat the dispersion or use larger volumes. In practice, open and mix it in a fume hood.

How should I store Nafion dispersion, and can it freeze?

Keep it sealed in glass, plastic or stainless steel between 0 °C and 32 °C, dry and out of sunlight. Do not let it freeze.

What is the shelf life of Nafion D520 or D521?

Chemours expects two years from the packaging date when the dispersion is stored as recommended. The packaging date is on the container label.

Why should a Nafion dispersion bottle be stored upright?

The alcohol solvent can weaken cap seals if it stays in contact with the lid. Storing bottles upright lowers the risk of slow leaks.

How do I dispose of leftover Nafion dispersion?

Collect it as flammable solvent waste and follow federal, state and local rules. Ask your EHS office whether PFSA waste needs fluoropolymer or PFAS handling.