Comments on: Disneyland Still Open as Chemical Tank at Risk of Exploding Forces Evacuation Orders 5 Miles Away.

By: CKNY

CKNY — Mon, 25 May 2026 13:27:51 +0000

We will be arriving at DLR in 13 days, hoping this is all settled (no pun intended) by then. We are thinking of everyone much more directly affected by this situation.

By: Tom Bricker

Tom Bricker — Mon, 25 May 2026 01:25:14 +0000

In reply to Kevin. Thanks for sharing all of this! In a comment on a Disney blog, you've provided better commentary than I've read in local or national media, which is both impressive and unfortunate.

By: Kathy

Kathy — Mon, 25 May 2026 00:26:23 +0000

Thank you for the update. I would cancel if I had an upcoming trip. Just too many uncertainties. Hopefully it won’t explode and they’ll be able to contain it.

By: Kevin

Kevin — Mon, 25 May 2026 00:18:34 +0000

In reply to A. Looking at those plumes it's not so bad. The IDLH (immediately dangerous to life and health) concentration for MMA is 1000 ppm and those maps are showing the worst plumes to be <10% of that once you get more than a couple blocks away. The OSHA permissible exposure limit is 100ppm for an 8-hr shift and they are even below that. I wouldn't want to breath anything near that for an extended period of time, but you would have plenty of time to evacuate in case of a rupture/plume. One of the characteristics of MMA is that is *stinks*. The odor threshold is <1 ppm. You would be driven away by the bad smell long before you get to levels that are dangerous.

By: Kevin

Kevin — Mon, 25 May 2026 00:12:45 +0000

I’m a ChemE who deals a lot with process safety (including methyl methacrylate) so this is in my wheelhouse. The article says “This appeared to be working initially, until it was realized that the interior had continued to heat up even as the exterior of the tank was cooled” – that’s exactly what would be expected. Tanks like this don’t have internal mixing and the polymerizaton is turning the monomeric MMA into solid poly-MMA which would further reduce any free convection. So they know that cooling the outside only has limited effect. The material will continue to heat in the center and have hot spots, the hope is that the rate is slowed and enough cooling happens through conduction so that a thermal runaway reaction is avoided. The “toxic chemical release” really is a good option. Tanks like this are diked, though this dike is filled with water. But other articles say they have blocked off any access to sewers and other waterways and are likely pumping out that water (and potential contaminants) to disposal. Other wise, most of the material in the tank is turning to a solid non-hazardous plastic which will eventually be chipped up and thrown away. We just want that to happen slowly enough that massive pressure build doesn’t happen. After this many days, I would feel cautiously optimistic.

Injecting a little politics, investigating incidents of this type to we can prevent recurrences across the industry is why the Chemical Safety Board exists. They do a great job and in time will publish a full report of what went wrong here (the company should have had monitors on the tank to look for the beginnings of reaction and been able to inject something like phenothiazine to stop the reaction. Articles say they couldn’t because it had already progressed too far and solidified in the injection ports, so something in their setup needs improving). the current administration attempted defunding the CSB, but luckily congress passed $14million in appropriations to keep the agency running. If their learnings can prevent an incident like this and a tank explosion, it will pay those appropriations back 10-fold not even including the potential for saving lives.

By: Tom Bricker

Tom Bricker — Sun, 24 May 2026 23:00:11 +0000

In reply to A. The element of the unknown is the biggest thing for me. The interactive map with the toxic plume and wind overlay definitely gives me pause.