I've told my 15-year-old son off because he's not allowed to use tools because he could cut himself if he touches something dangerous.
What's the right age limit for using tools?
Please use an age, like 45 years old.
Using tools is not based on age, but instead on maturity and training.
My 9-year-old has his own toolkit. There is a screwdriver, hammer, saw, and a couple other things that are his.
He needs to ask permission before "fixing" or building anything (largely to ensure it's not something I particularly want to keep in one piece). However, as we work together on projects, he learns how to use the various tools and I learn what his relative skill level is (and use that to decide how much I need to hover when he starts his own project). He can hammer unsupervised, he can't touch a drill without asking (because that's Mommy's drill, in addition to safety reasons!)
The toolkit includes items like safety glasses and band-aids. This helps emphasize proper and safe usage; putting on goggles to protect his eyes every time no matter what also helps get him in the right frame of mind. Tools are not toys, and should be used properly both for safety and effectiveness (hammers are for nails, screwdrivers for screws, etc.)
When he's helping me on a home improvement project, he brings his tools even though I've got my own. They're sized for his hands and grip, and he is learning how to select the appopriate tool for the job. If he needs to borrow something, however (e.g. I've never bought him a hacksaw), he can.
A teenager should get training on how to properly use tools to ensure that he will not injure himself (or damage the tool or work). Banning tools as dangerous restricts his ability to learn -- nobody magically has the necessary knowledge to effectively use a hacksaw once they reach a certain age, it comes with experience (and ideally with tutelage).
I would say that 15 is plenty old enough to use a screwdriver or drill or hacksaw. For reference, in my boy scout troop, nearly every boy earned a Whittling Chip (even if they had already earned in Cub Scouts, we had them earn it again) within their first year (so 12 years old or so), which gave the right to carry and use pocket knives. Generally a year or so later (we held the training biannually, so 13 or 14) they would earn the Totin' Chip, which covers saws and axes(much more dangerous than saws).
Here is my view of the tools in question.
A screwdriver is perfectly safe. My five-year-old nephew is allowed a small (two inches or so), but metal screwdriver.
A drill is relatively safe. Unless he's doing something plainly and clearly unsafe, like my nephew who likes to drill himself or others with his toy electric drill.
A (hand)saw is acceptably safe. It has teeth which can cut you, but not really too badly (I speak from experience). On the other hand, when I was 16 I used a infinitely more dangerous power saw as I helped build the stage for my drama class.
The bigger question is, what (and where) is he using these tools on. For example, sawing something you don't want destroyed, or sawing or drilling something. Example: don't saw on top of a granite countertop; that's what a sawhorse is for.
But the core of the issue is this. You are trying to stop your son from partaking in activities that are potentially dangerous to him. There is a catch all term for these activities: life.
Your son is fifteen. In the US, he would be a year away from being able to gain (or, as CorsiKa points out, might already have) the legal right to drive a car, a device which kills* more people (in the US) than guns. Two years later, he would be considered a full adult, thrust in a world full of dangers physical, mental, emotional, financial, and social. These dangers cannot be avoided by forgoing activities; they have to be recognized and either dealt with or mitigated. Now is the time for your son to begin learning of these things.
*Whether guns kill more or less than cars, or are more dangerous than cars, depends on the year in question among other factors. I don't want to get into an argument about this; the point is the car can be dangerous, and the OP's son is at the point where society views he can be trusted with it.
It's really up to you to decide. The important thing to keep in mind is your knowledge of your son's abilities. Is he good with his hands? Do you let him use knives? If you trust him to be capable and teach him the skills he needs to be safe, he will be. In general, I've found that kids are more capable than we think they are.
Personally, I think that what's important is teaching kids to respect tools that are dangerous so that they know how to use them appropriately and carefully. Fifteen is, in my mind, well old enough to entrust with this. High Schools in the US regularly teach shop class with power tools to their students, which gives an age range of 13-18 years old. Your fifteen-year-old should be more than capable of managing a powered hand tool and could probably be quite handy with more complex tools like lathes, jig saws, etc... if he's properly trained how to use them.
Here's a great article from NPR about a camp giving young kids (4-9) access to power tools to make their own board games.
Penelope is spending the week at a day camp run by Construction Kids. The Brooklyn-based program offers building classes throughout the year for kids as young as 2 years old. It's one of a new and immensely popular wave of programs trying to shift kids away from computer screens toward actual, hands-on activities. Like building things from scratch.
With help from a team of adults, the children in this program will design and make their own game boards, foosball tables and models of cities. Even the Brooklyn Bridge.
And from the info page on the program's website:
ConstructionKids offers year-round instruction. Children learn to use real tools and get to build projects, in a safe and creative environment. During the school year, we provide hands-on field trips and after school programs for Pre-K to 6th graders, and Holiday Builds and Birthday Parties for children ages 4-9. During the summer we offer week long Summer Day camps at multiple locations throughout Manhattan and Brooklyn.
In times past, we trusted kids with small knives at 6-7 and taught them to whittle. They were taught to cut away from themselves to reduce the risk of injury and we let them be creative. If a 6-year-old can whittle, a 15-year-old can use a screwdriver.
I owned a bicycle since before I was 7, and learned how to maintain one almost from that time (using screwdrivers and wrenches).
My father designed/contracted our family home when I was 12, and taught my brother and I many things related to its construction such as basic carpentry, plumbing, and wiring - how everything is put together and how to do it safely - how to work on wiring without getting electrocuted, how to solder copper pipe, how to cut, screw, and nail wood, and be able to do it all without supervision.
Even before high school, "shop" classes exposed me to both hand and power tools (including drill press, band saw, and lathe)
When I started high school at about 14, I took carpentry "shop" and worked with more power tools - table saw, radial arm saw, plane, jointer, router.
As said in other answers, it's not about a specific age, but about being taught when ready to learn, and progressively building experience. It's about being taught respect for dangerous things, exactly what the dangers are and how to manage those dangers when using the most appropriate tool for a job to get it done safely. There's no substitute for experience. Minor nicks, cuts, and scrapes are inevitable and part of the learning process, but there's no need to lose a finger or an eye.
If you keep your son from handling a tool because it's dangerous, he'll never learn to use it. He will either grow up in fear of handling any tool and never doing anything "handy", or may end up injuring himself in an attempt to use something he was never taught to use properly.
To be honest, some power tools are a little scary to me, but that's probably more because I haven't had much experience with them, because I haven't had the need. I think a little fear can be a good thing - it can keep you from doing something dangerous, but it can also get you into trouble if you approach a task too timidly.
I would say that at 15, your son is overdue for training on how to use pretty much any tool. The approach just needs to be structured around identifying hazards and safety precautions, demonstration of how to perform a given task safely, and supervised hands-on experience until he can show that he can work safely. After that, you have to trust that he can be safe without supervision.
I was 35 before I used a circular saw, mostly because Dad never let me. So up until then I was using a hand saw/panel saw/tenon saw or hacksaw, or sometimes a jigsaw to cut things.
My own youngest boy showed a fear of sharp things like knives. He wouldn't even wash or dry a sharp kitchen knife. So we've worked out a mantra of
Respect the tool, don't fear the tool
...and that's helped him focus on the tool, what the potential dangers are, and how to minimise risk.
To answer the question, now is the right age to start using a tool.
For a younger child, you can get them to hammer nails into polystyrene blocks.
Medium age kids can help in the garden with all manner of cutting and sweeping and digging tools. Construction and repair is also a great time to show how a tool is used, point out the risks, and then let them try the tool either on a scrap, or help you on the job.
As an early teen, my eldest helped me build an outside stool from some offcuts of framing timber. 15 years later I still use it - long after he left home.
If you're still looking for a specific age, I'd say about five years old.
Inuit children are given razor sharp knives as soon as they're big enough to hold them. I started teaching my nieces and nephews how to shoot when they were about five years old. I can't remember ever not having a razor sharp knife in my pocket, since my uncle gave me one of his when I was five or six. I can't remember my dad teaching me about power tools, but he had a whole shop full of them that I had access to, as did my brothers and our friends (with closer supervision by my dad since he didn't know their capabilities like he did ours). Oh, and my mom used to say I've got a scar for every week I've been alive. You're going to get cuts and scrapes when you're using tools, it's part of the experience.
In short, I think your son is way behind the curve on learning how to use tools. Give him access (and permission) so he can catch up. Allow him to make mistakes so he learns from them. He'll get cuts and scrapes, bruises and scars, and he'll be the better man for them.
There's no simple answer to this question in the form "X years" as you'd hoped for. The right age for a child to use tools depends on the tool, the child and the parent (or other supervising adult).
To assess the what's right for your situation, consider the following checklist, which applies to all tools, from a paintbrush or mixing spoon right through to a chainsaw or bulldozer. If you can't satisfy any of the headline statements below, then you might need to
Like all learning experiences, if it's imposed on the child then it's probably going to be counterproductive. Children are most likely to ask for tools to help with their own projects, such as making a dolls' house or model railway, but may also want to help the parent with household repairs or making furniture, for example.
Usually it's obvious if a tool is too large or heavy for the child. Some common tools such as scissors come in small sizes especially suited for younger children (often too small for adults to use effectively). Also consider the degree of control required; for example a hand-held power drill requires much more coordination than a workshop pillar drill. Depending on where you live, there might be legal restrictions on age when using vehicles, firearms or explosives.
As you're concerned about safety, you'll want to teach the proper respect for (but not fear of) tools.
You might find that you're a better teacher if you ask the child to suggest safety precautions, rather than simply reciting them yourself. If you ask, "how could this hurt us or make a mess, and how can we change that?" you'll have an engaged youngster actively thinking about safety, rather than a bored and impatient one.
It definitely helps if the child can understand the reason for each precaution we take, such as why we cut away from ourselves and other people, and why we always use a solid backstop for airgun targets. The "explain, not tell" rule also holds for instructions that improve the quality of results, such as how to hold a saw for a straight cut.
Try not to be too anxious yourself. If you're unable to hide your anxiety, you might want to ask a trusted friend to supervise and teach on your behalf. Also, make the instruction appropriate for the child: for example, when I started my engineering degree, the university showed graphic photos of the consequences when a person's hair is dragged into an electric drill - that jolted the undergraduates out of their complacency, but there's no need to scare pre-school children like that!
This means that you should demonstrate the use of the correct safety equipment, not merely insist on "do as I say, not as I do". For instance, always use oven gloves for handling hot dishes, safety glasses when drilling or sanding, and ear protection when breaking up concrete. Again, consider asking a trusted friend (or an organisation, such as Scouts or other youth group) to demonstrate and teach the use of tools you're not confident enough with.
It's no good being in a hurry to complete your project. If you are, then you should probably defer the teaching to a more suitable time. You need to be able to go at the child's pace, to tolerate their early mistakes and to answer their questions. You should allow some extra time for practising on scrap material before committing to making the once-only cut on their valuable workpiece.
Most of the above sounds like statements of the obvious, but I hope it gives you a tool (!) to assess what's right for you and your child.
I would normally expect a 15-year-old to be familiar with hand tools for woodworking and simple metalwork (saws, files, chisels) and with some power tools (pillar drill, bandsaw). When I was at school (in the 1980s in England), all pupils were taught the use of these tools around age 12-14. As I had a farm upbringing, my personal experience is probably not representative, but suffice to say that with the right environment and opportunity, I was able to use just about any tool except the arc welder by the age of 15.
I handed a 6 month old a stick and celebrated her copying me smacking things last weekend.
The main point of tool use is learning. Everything is dangerous if you don't know how to use it, so you let them learn in low risk ways. Let them observe someone using a tool (correctly), let them play with toys, let them practice with simpler tools first and always watch them and offer corrections and encouragement.
I made a watchtower for my Action Man (GI Joe in the US) when I was 8, with minimal help from my dad. I don't know when I first started using real tools, but clearly by this time I knew how to use a saw, hammer and nails. At age 10 we were making simple models at school with balsa wood, hacksaws and chisels. When I started senior school at age 11 we had woodwork lessons using saws, chisels and drills. And when I started Scouts at age 11, all kids were taught how to use a knife, bow saw, hand axe and felling axe on their first camp, because each patrol had to maintain their own stack of firewood.
If your son is 15, then the only reason he might not be safe around basic hand tools is that you haven't taught him how to use them. Assuming your son doesn't have learning difficulties or physical handicaps which would affect his ability to use them safely, he is at least 5 years past old enough that you should already have taught him how to use them. Any age limit for your son is null, void, expired and so far over the horizon you couldn't see it with a telescope.
I was taught to use wood-working tools (hammer, screw-driver, hand plane, hand-saw, hand-held electric circular saw, electric drill, sand paper, paint, also sewing needle) at home when I was a child. Not to mention kitchen knives.
Later I was taught to use power tools, at school, when I was about 14: that included chisels (for cutting wood), drill press, table saw (a circular saw, not a band saw), lathe.
Our wood-working teacher was missing part of one finger -- when he taught us safety, he knew (from personal experience) what he was talking about! The safety lessons weren't only about sharp tools: they included wearing a mask to avoid wood-dust, safety glasses, etc. Also, what can go wrong (e.g. that a power saw might snatch the wood if it hits a hidden nail or knot), and how to mitigate that (use a tool, not your hands, to feed the wood into the saw).
At home and at school I was usually supervised, at least initially: e.g. at home I was "helping" an adult to do something; at school the teacher watched people work.
I was taught to drive a car, and handle a military rifle, when I was about 16.
As a teenager I also sometimes used a big (two-handed) axe for splitting logs.
There are many machines that I haven't learned to use (e.g. motorcycle, pistol, chain saw, band saw), and (knowing tools are dangerous if mis-used) my inclination is to not touch one until or unless someone taught me how to use it.
I coach a Destination Imagination team for 2nd to 4th graders (7 to 10-year olds). Outside of your question, first and foremost, no matter what tool and what age, personal protective equipment is most important. Goggles and earplugs when appropriate.
Past that, I don't think there is a good hard and fast age line. I believe that much of safe tool use is proper training, and having the opportunity to build the experience of using more and more useful/dangerous tools with proper supervision. My DI team started with hammers and screwdrivers, then moved on to hand-saws and drills, and towards the end, my 7-year old was safely using a pneumatic nailer (with supervision). My line at the moment is that they can use tools that produce life-lesson injuries (cutting themselves with a jigsaw, or a razor knife), but can't use tools that produce life-altering injuries (cutting off a finger on the table saw). That means that the router table was off limits when it had a full size router mounted on it, but when I mounted a Dremel tool that would only make a nasty cut if they screwed up, I taught them how to use it.
When I was 12, I received my first shotgun, along with a very strict lesson in gun safety. That year I also was taught how to use a table saw. (Note,I am 60 now and I still have all my fingers!). Over the course of my life I have used band saws, jigsaws, lathes, mills, grinders, routers, and many other power tools and hand tools. Moreover, when I was 9 or 10, I went to a summer camp where we had classes in archery, whittling, and shooting (with single shot .22 rifles). I never saw any accidents, because we were taught how to safely use the 'tools' and were closely supervised. As many other responders have pointed out, you learn responsibility by having responsibility. When it comes to tools, you start small and work your way up. As one of the previous posters so aptly stated "respect the tool, but don't fear the tool". There IS a difference. Final note, I grew up as the son of a hardware store owner, and my grandfather was a cabinet-maker by training. Having and using tools is part of our family tradition. Every year at Christmas, all us children (my sister included), received a small hand tool among our presents (usually a screwdriver, or pliers or such). By the time we were teenagers, we all had our own tools and knew how to use them. Don't stunt your child's development because of your fear of tools. Find someone to teach him how to responsibly use tools. He will thank you for it many times during his life.
I had to wait until I was five to get my first proper sharp knife. The benefits of introducing tools early, explaining the risks, and of course being with your kids very closely when they first start being hands-on with them, are lifelong. We can be told "always keep behind the blade" etc. but to write this pattern into our nervous systems probably needs actual experince. With my own daughter, from the start I have tried to instil a feeling for what is really dangerous (cars, electricity and poisons - we don't live in the USA so we don't have to worry about guns) and otherwise have encouraged her to explore and to trust her instincts. What's the worst that can happen with a hand tool? This is a serious question - think about it. The occasional bleed is a learning experience, but some kinds of damage are serious and permanent - so always have eye protection handy, and use it. If everything is painted as horribly dangerous, how can our kids learn about risk?
Do not underestimate the ability of young people to learn. By the age of three they have already accomplished the two most complex physical skills they will ever develop - how to talk and how to walk.
Both our children attended a Montessori preschool from age 3 to 6. In their first year they commenced "carrot work" - learning to slice carrots using sharp knives (because in many circumstances, a blunt knife is more dangerous than a sharp one). They learned respect for the tool, manual dexterity (so much Montessori learning is based around fine and coarse motor skills). It was also noticeable that the Montessori school never used "unbreakable" or "safe plastic" objects. In exercises such as pouring liquids or solids, jugs and bowls were good glass, crystal or china - once again, learning respect for materials, and, following the occasional inevitable breakage, how to clean up safely.
Screwdrivers and spanners? I believe the guideline age for "Meccano" construction toys was 6. I was certainly building with it by then.
However, it is possible that the nature of our motor-skill abilities has changed quite drastically over the past decade or two. On the one hand, my 10 year old son can outplay me at anything requiring swiping on a tablet. On the other, my wife, who teaches crafts to a wide age range, has observed a significant fall-off in basic dexterity - such as how to use scissors or sew in children. If that persists, will it lead to a human race who can only do things by voice command?
With many tools, a grasp of the basic physics is important to safe use. For example, if you merely sit a small piece of wood on a workbench and attempt to drill it with an electric drill, it will most likely spin around, (mildly) hurting the hand with which you are attempting to hold the wood, and possibly sweeping other items off the bench - something I learned myself the hard way. Attempt #2 utilised the vice and was successful.
Is it possible that your reluctance stems from a lack of experience or training with tools yourself? In that case, perhaps find a friend or relative who can guide your son
I'll structure my answer by breaking it down by category of tool. For the age suggestion, I'll be a bit generous; a mature child could handle them a couple years sooner. He should start out supervised for every tool, but if he is doing things correctly, you need not supervise him for long.
Wrenches, screwdrivers, etc.
He should be perfectly fine using any sort of these.
Approximate age: 4 years old
Hammers, knives, chisels, hand saws, etc.
The worst-case scenario is he cuts himself and maybe gets a scar, but he won't do it more than once.
Approximate age: 7 years old
Power screwdrivers & drills
As the category name says, it'd be quite difficult for him to hurt himself with these. These are safer than some of the hand tools. Just wear eye protection when drilling.
Approximate age: 7 years old (or when they're strong enough to hold and control the tool—power driver/drills can make quite a bit of torque)
Jigsaw, reciprocating saw, scroll saw, router, high-speed rotary tools (e.g., Dremel), etc.
These can fling stuff at your eyes, and they can potentially cut you, but only if you're careless. Just wear eye protection and always grip the tool confidently.
Approximate age: 10 years old
Table saw, circular saw, miter saw, and any other saw with a spinning blade
An inexperienced person should never use these without experienced* supervision, regardless of their age. Unlike the other tools, these can pull your workpiece and/or fingers in if you don't use them correctly.
Approximate age: None
*Experienced supervision means if you don't know how to safely use them yourself, you won't know what to look out for when he uses them, and therefore you cannot be the sole supervisor.
Make sure he keeps his workspace neat, organized, and free from all tripping hazards.
Respect the tools for their power, but do not fear them. If you fear them, then you cannot control them.
As many others here have said, I believe that you're coddling your son a bit too much. If you try and protect him from every danger, he'll never be able to handle them himself. (Also, getting a cut is not the end of the world.) It's probably hard to hear, but he's most of the way towards being a legal adult, and he ought to have a proportionate amount of responsibility and trust. This goes not just for tools and handiwork, but in all areas of life and adulthood.
Personally I used all non-powered tools by age 7. At that point it was under observation, but by 8 or 9 I could use all hand tools I wanted from my own toolbox as much as I wanted.
I had my own knife for woodworking around 7 also. I was allowed to use hand-held power tools when I was 12 or so, but I preferred not to until I was an adult and had to.
I've never hurt myself on any of these tools.
Unless he has motor skills problems or is particularly careless a teenager of 15 should be perfectly capable of using all tools except large machines.
I know a lot of others have posted but personally since about 9-10 I was allowed to use basic hand tools without asking as long as I put them back. At around 13-14 I was allowed to use powertools without asking (including sawzall). At around 15-16 I could use every tool at will as long as I put them back
I have not gotten hurt and have been able to do lots of stuff on my own.
Summary: Schools in Britain let students of 15 play with all sorts of dangerous tools and it works out just fine. The danger of any tool stems from lack of concentration, lack of knowledge or lack of sensible behaviour rather than from the tool itself. The tool defines the worst case scenario, the wielder defines the chances of that scenario happening.
This answer is somewhat cultural, but as it reflects what our government expects children in my country to be mature enough to do (which implies a comittee of educated people had to sit down, debate and discuss this very issue) I feel it is a suitable guideline.
When I was in primary school (Britain, ages 4-11) they let us do sewing and use needles at the age of at least 8/9. By 10/11 they let us use the hot glue gun (supervised).
In secondary school (Britain, ages 12-16) they let us use all manner of carpentry, metalwork and electronics tools by the age of about 13/14/15. Drill presses, files, saws, clamps, hammers, rivet guns, soldering irons (running at over 300C, very hot). In fact they let us use bunsen burners (i.e. a very hot open flame) in science from nearly the first week. And oddly enough, I don't remember anyone ever having a major accident when handling any of these tools because everyone knew they were dangerous and the teacher was very vigilant.
There were a few small cases of minor injuries (burnt fingers, minor 1cm cuts). The worst accident I ever saw at school was someone accidentally knocking boiling water over someone else when doing a simple science experiment, which just goes to show it's more about concentration, attentiveness and alertness than how potentially deadly the tool is. (The person only had very minor burns. Probably because they were wearing leggings, which is probably why they're listed in the optional section of the school uniform).
Personally the worst accident I had was a rope burn when I went absailing as part of a school trip, which was the fault of the facility we were visiting for not providing gloves (and arguably me for not asking about gloves, but at least I know now and the scar is so faded only an M.E. could spot it).
Does he use a knife and fork? when did you teach him how to use them and does he understand how dangerous they could be? When I was 12 my school curriculum taught us to use pillar drills, table saws and lathes with wood and braising and gas welding and gas cutting with metals. They don't get much more dangerous than that. I owned my own soldering iron at age 7. Experience is the key factor here, not age.
At age 15 I was doing all the electrical jobs in the house. I was far more capable of it than my parents, and indeed more capable than I am today at 65. I did make the odd mistake, but how else do you learn?
If a 15-year old wants to tackle such jobs, encourage it, but obviously check that he/she is properly equipped for the task and knows what safety precautions are appropriate.
Throughout most of history, 15-year-olds were regarded as adults and were out and about doing useful work. They need to be flapping their wings and leaving the nest.
I think the tools need to fall into some categories.
Tools that can't easily cause harm to the occupant:
These tools can harm them and require some training, talking to them, and teaching them what they should and should not do with them, but also have less potential for "accidental" injury. The age group for this should be around 3-8 or so with stress on the teaching them and helping them learn part. I feel that they should have a good understanding of these tools before going on to the next category even if their age warrants them to.
Tools that can cause harm to occupant but not easily cause death or permanent damage to self or others:
These tools require a bit more training and teaching and should be used at an age of about 14-16. Keep in mind that for boys anyways the Boy Scouts start at age 14 or so and there they learn how to use a pocket knife, hatchet, hand saw, etc.
Tools that can cause big damage or death:
Some bigger tools can cause serious damage or death to them so like the others this level needs to come after the other two. I would recommend age 16+ but only if they understand them well and you have been by their side many times before.
This is just from a safety standpoint but also it is important to teach them good practices and skills for each so they end up using the tools well and coming out with good projects too.
Remember, by law, at 15 and 6 months of age, a youth can get a Learner's Permit, to drive a car. The use of hand and power tools should prepare them for this step.
I would probably say around 9 with supervision.
Around 9 years old I was allowed to use a gun - and apparently I was viewed as a bit of a rambunctious unruly child, because everyone went on about how mature I was when I handled the gun.
I would say if you think the child is capable of understanding the gravity of the tools and how they could lead to damage/pain/etc, then they should be allowed to use the tools, once again, under supervision at first.
I think that this would strongly depend on how responsible the child is, if the child respects the tool and dose not mess about with it i would say that the child should be able to use tools.
I am only 15 however i have used large tools like table saws and mitre saws since i was around 13 years old, and i even have my own workshop
I was using screw drivers, hammer/nails, low voltage (1.5, 3, 9, 12) electric wiring, pocket knives, stove top, oven, washing machine, and hand saws (not power saws) before I turned 11. I learned to swing an axe when I turned 12. I was introduced to soldering electric wires before 13. I very strongly suggest not providing a pocket knife to a pre-teen, not because they might use it poorly, but because they might forget to leave it home when going places it shouldn’t go, and kids are often not treated in a reasonable manner for that sort of mistake.
Like everything else with potential danger, (1) start small, safe, & supervised (ex: nuts & bolts & wrenches) until they are safe without supervision. (2) Introduce something a little less safe, until they are safe without supervision. (3) repeat step (2) until you’ve run out of things to teach. If you want to skip the “supervision” part, skip the “introduction” part too. When they want to jump ahead, explain step (2) as how they get there.