Reminds me of the time I was working on a remote repeater site and called down to the landowner to bring me some water for the batteries. His father brought up a couple gallon jugs of what was supposed to be filtered water. I started pouring the liquid from them into the batteries and had an eruption shortly thereafter. Apparently the old man had mistakenly brought me up a couple of jugs of 10 molar muriatic acid. The problem was, these were in the sort of 1 gallon plastic jugs typically used for water or milk, with no labeling on them at all.

The scary part; it was in the 90s that day, and I was contemplating taking a big swig before putting any in the batteries. That one had me contemplating life for a bit.

On the lack of fire extinguishers in the UK, the Get Out, Stay Out, call the Fire Brigade advice is probably appropriate. Not only are folks susceptible to smoke inhalation and failing to evac others, but in the US something like only 1 in 10 have ever actually fired off an extinguisher before they actually need to. It's not rocket science, but there's some chance that the extinguisher could be past its expiration, or they may seriously underestimate it's firefighting capacity, or not follow the PASS guidance. And I expect the fire brigade is almost immediately on scene once alerted, mitigating damage / loss. Modulo the 'in event of a greater emergency' scenario.

That said, everyone should practice with an extinguisher - you get to burn things, and put them out, what could be more fun. I used a 5 lb CO2 model approaching its 5 year expiration to have my wife and kids practice putting out some contained fires in the backyard. A little messy, but a good time was had by all.

For test driving a fire extinguisher you might also try your local fire department. One of the local towns that i worked in a few years ago had free training classes on fire safety and how to use a fire extinquisher. Didn't make it to the class but i did talk to one of the teachers/trainers and he said that they set up a controlled fire for practice and anyone who wanted to pull the pin could do so with expert supervision.

I keep my keys in a safe (which has a combination lock). The idea is that burglars will get in any way they can, and the first thing they will do is look for a way out. They know they may be in a hurry when they leave, so they won't want to be squeezing through small openings or breaking glass. Ideally they want you to hang the keys to your back or front door on a hook in the hall, so they can open the doors and carry out armfuls of your stuff without undue inconvenience.

I don't have fire extinguishers. I doubt their effectiveness. I do have a fire blanket for small kitchen fires, and smoke and CO detectors. I sleep in the back bedroom instead of the front, partly because that is where the emergency exit is.

I keep a hefty crow-bar under my bed, in case I have the opportunity to dig myself out after the house collapses during the night.

I have stockpiles of food and water etc for sheltering in place, but I think that's another topic.

As a former firefighter, I can tell you that in the right hands, a proper sized (10 lb) fire extinguisher can be a very effective tool.

All tools regardless of their usage, require proper training and know-how. You may not have this knowledge, however others do and you never know who is going to be with you or close by when the time comes to effectively utilize that tool.

That being said, there is also a fine line in trying to contain a fire and knowing when to get out to save your own life or more importantly other people's lifes.

Some fire departments offer basic training for the public in using fire extinguishers etc. It may be worth your time to check with your local fire department.

So do you put your keys in the safe when you are at home for the night? If so, what do you do if you need to exit via the front door quickly in the event of an event of an emergency?

No. Spare keys live in the safe. Working keys are in my pocket, or on my bedside table when I'm asleep. My keys are part of my minimal "every day carry", and I like to keep them on my person even when at home.

The safe is to prevent burglars using the keys if they enter the house when nobody is home. If someone's home, then it's a whole other situation.

The last time I saw someone use a fire extinguisher was over at a barbeque at a friend's house. He had turned off the grill, and we had been eating at the dinner table for 5 minutes or so when I noticed huge clouds of black smoke on the deck. It turned out that the grease trap below the propane grill had caught fire and had also ignited grease inside the grill itself. The thermometer near the propane tank was pegged off the chart.

Luckily, two of the people at the dinner were firefighers. Unfortunately, they then went on to have an argument about whether the best course of action would be to 1) open the lid of the grill, allowing some of the heat to dissipate away from the propane tank and then extinguish the fire, or 2) leave the lid closed so as not to add more oxygen to the fire, and try to extinguish it from below. After a minute or so of this, a non-firefighter at the table got up, grabbed a fire extinguisher, threw open the lid and put out the fire. I'm still not sure which firefighter was right, but I'm glad the non-firefighter knew how to use the fire extinguisher.