Urgent Chemical Safety: Acetone in Plastic, Methylmagnesium Chloride SDS, and More

If you're asking whether acetone can go in a plastic bottle, the answer isn't a simple yes or no. In my experience coordinating lab safety for the last 8 years, HDPE or glass is the only safe choice for acetone storage—with a few caveats I'll get into below. And if you're here because you need a Sigma-Aldrich methylmagnesium chloride SDS or the hazard statements for methyl iodide, I'll point you to exactly what matters. The short version: both are dangerous in different ways, and the SDS is not just paperwork—it's the difference between a close call and a serious incident.

Why you can trust my safety perspective

I'm a safety coordinator at a chemical supply company. I've handled maybe 250 urgent SDS requests over the years—close to 300 now, I'd have to check our log. In March 2024, we had a researcher call at 6pm needing a methylmagnesium chloride SDS 90 minutes before a grant deadline. Normal turnaround is a next-day response. We found the SDS, flagged the pyrophoric hazard, and helped them choose a safer handling setup. Their alternative was to wing it with a similar-looking reagent. That's when I realized: the SDS matters most when you're already in a hurry.

The SDS lookups you probably need right now

Let's start with methylmagnesium chloride. This is a Grignard reagent, and it's pyrophoric—meaning it can ignite spontaneously in air. The Sigma-Aldrich SDS lists the critical hazard statements:

• H250: Catches fire spontaneously if exposed to air.
• H260: In contact with water, releases flammable gases which may ignite spontaneously.
• H314: Causes severe skin burns and eye damage.

I've seen researchers treat it like just another bottle of something reactive. It's not. One colleague nearly lost a hand when a syringe slipped and the reagent hit the air. That's why the SDS doesn't end with hazard statements—it includes handling requirements like working under inert gas and using a fire-resistant glove box. Don't skip those.

Methyl iodide is a different beast. Its Sigma-Aldrich SDS hazard statements are:

• H301: Toxic if swallowed.
• H312: Harmful in contact with skin.
• H331: Toxic if inhaled.
• H351: Suspected of causing cancer.
• H400: Very toxic to aquatic life.

The conventional wisdom says methyl iodide is just a methylation reagent. My experience with 50+ orders tells me it's the one people underestimate most because it's a liquid with a sweet smell. That smell is a red flag, not a quirk. Always use it in a fume hood, and make sure your gloves are rated for it—standard nitrile gloves degrade quickly.

Safety hazards of acetone: more than just a solvent

Acetone is everywhere in labs, which is exactly why it gets ignored. The main hazards are flammability and vapor accumulation. Its flash point is around -17°C, so it's not the liquid that ignites—it's the vapor. I've seen fire risk assessments miss that an open bucket of acetone in a small room is essentially a bomb waiting for a spark.

It's also a skin irritant and dries out skin fast. That might sound minor until you have a cracked hand and then put on nitrile gloves. The combination is painful and increases exposure risk. Use appropriate gloves, and keep containers closed.

Can acetone go in plastic? The real answer

Short answer: only in the right plastic. Acetone will dissolve polystyrene, polycarbonate, and many other common plastics. It will also soften PVC and cause crazing in some acrylics. The plastics you can trust are HDPE (high-density polyethylene), polypropylene, and PTFE. In practice, I always recommend glass if you're storing it long-term. HDPE bottles are fine for short-term holding, but I've seen acetone slowly migrate through the plastic wall over days—you end up with a sticky mess on the shelf.

Everything I'd read before I started this job said “acetone is safe in plastic.” In practice, I've seen a bottle of acetone melt through a plastic test tube rack within an hour. The rack was made of polystyrene. So the nuance is: it depends on the plastic. Check the resin identification code and, when in doubt, use glass.

Flame retardant sheets and storage essentials

If you're handling pyrophoric reagents like methylmagnesium chloride, you need more than an SDS. You need the physical setup to match. That's where flame retardant sheets come in. I'm not talking about lab coats—I mean fire-resistant bench liners or blankets rated to resist flame and protect surfaces from ignition. We use them on work benches where Grignard reagents are opened.

I should add that a flame retardant sheet is not the same as a fire blanket. A fire blanket is for smothering flames on a person. A flame retardant bench liner is for protecting the workstation from splashes and sparks. Both have their place. If you can only buy one, buy the fire blanket first—human safety beats equipment every time.

For storage, keep pyrophoric liquids in a fire-rated cabinet, away from water sources, and never store them near oxidizers. That last one sounds obvious, but I've audited labs where methyl iodide was sitting on the shelf above a bottle of hydrogen peroxide. The GHS labels say “keep away from oxidizers” for a reason. It's not a suggestion.

Where my advice has limits

I want to be honest: I'm a safety coordinator, not a toxicologist or a chemical engineer. I can tell you what I've seen working with hundreds of lab staff, but I cannot tell you the exact incompatibility of every plastic with acetone. That depends on temperature, concentration, and exposure time. My recommendation is to always check the technical data sheet and the SDS before you commit to a storage container. At least, that's been my experience with deadline-critical requests.

Also, this article is about the most common hazards, not the complete list. For methylmagnesium chloride and methyl iodide, the Sigma-Aldrich SDS includes sections on accidental release measures, handling and storage, and toxicological information. Those sections matter every bit as much as the hazard statements. I've seen people focus only on H-numbers and miss the disposal requirements or the first-aid instructions. Read the whole document.

And one more thing—if you're ordering these chemicals for a new project, don't wait until the night before the experiment to find the SDS. That's the rookie mistake I made in my first year. I assumed 'pyrophoric' was a minor hazard. It cost me a damaged glove box and a week of delays. Learn from that. Get the SDS when you place the order, not when the container is already in the hood.