I get asked this question a lot, and it is an extremely important topic. So I figured I would talk about it a little bit today.
First off every gun owner is 100% responsible for making sure that their firearms can not be accessed by ANYONE else. This means that firearms that are not under your direct control (on your person) should be unloaded, and in a locked container that is not accessible by any unauthorized person. If you keep your firearms unloaded and locked away in a place where your kids cannot access them then you have nothing to worry about.
Aside from making sure that your kids can never gain access to your firearms without your permission, it is also important to educate your children on safe firearm handling. Children by their very nature are extremely curious, and observant. By hiding your guns from them, or even just never talking to them about them, they will become curious about them and want to go investigate. They will look for ways to find them and play with them because they are curious and they want to see what it is that is so "cool" that you won't let them touch it.
So my recommendation and how I handle this with my own children is that I hide nothing from them. I show them everything and explain everything. They all know that they are never allowed to touch any of my guns ever, but they also know what a gun is, and how it works. I show them all of my guns, I explain to them how they work, and that they can be dangerous, and that they aren't toys. I answer any questions they have about them. I have also ingrained in them the 2 most important firearm safety rules and a 3rd rule that is also very important for children. The first 2 rules my 4 and 5 year old both know by heart. First is to always make sure the firearm is pointed in a safe direction (NOT at any people or animals) , and second is to keep your finger off the trigger until you are ready to shoot. The third rule that is important for children is to never ever touch a firearm of any kind without permission. For my kids, that means with me there handing them their BB gun to shoot. They both know that if you follow these rules you can never accidentally hurt someone. I even take my 2 year old out to shoot the BB gun. He may not be old enough to understand the rules, but he is watching and learning too, and by watching and learning and getting to shoot the BB gun with my help it eliminates the curiosity factor.
My kids are still a little bit on the young side to be shooting actual firearms, but by teaching them about guns, and the firearm safety rules, and letting them shoot a BB gun, I am teaching them to respect firearms, and they understand that they are not toys, and what to do if they ever find one some where else. We can only every control what goes on in our own homes, and never know what they might see of find when they are not with us. I would much rather have my children educated and know what to do when they find a gun while at a friends house then be curious and want to play with it before they get caught.
So overall to answer the question "When should I start teaching my children about firearm safety" The answer is as soon as they are able to understand which for most children is around 2 years old. Am i saying you should hand a gun to a 2 year old of course not!!! But if you are going to have firearms in your home and / or carry one on your person, you better make sure your kids understand and respect them.
If you have any more questions about this topic please feel free to reach out to me.