1. Safety rules and hazards in electrics and electronics

Hello.

First of all, as this is first post in the series - all the posts starting with numbers are going to be parts of electrics and electronics tutorials/lessons course following each other while unnumbered ones will be on different topics loosely connected with this blog's theme ;)

This post is about hazards and ways to avoid them in electrics and electronics.

Read it or face consequences. Electrics and electronics mean playing with electricity, usually having connection with 130-230V electric grid (depending on country) and with some components that can be loaded to thousands of Volts, all of which can electrocute you instantaneously.

There is this and many more dangers which you usually could avoid easily if you know what you're doing.

Or kill or harm yourself if you don't.

Hence this post.

I'd like to point out that this part is about your personal safety. 

Safety of equipment, of electronic parts you'll mount or dismount - how to not damage them - is a completely different topic and I'll write about them when I'll be writing about those parts.

Now, to the topic.

* Electricity.

High voltage and high amperage. While I will explain whole physics behind this later on. The important part is, electric current can kill you. It is Amperes that kill, however Volts are what's needed to 'push them through' your skin which is a natural insulator against low voltages.

Usually 30V is considered a safety border with anything above that dangerous to health or life. 

Most electrocutions happen at 50V and higher, that doesn't mean you should feel safe with low voltages because with high amperage even if you won't get killed you can get burnt or otherwise hurt depending on what will the current meet on its way.

The current at which you 'can't let go' the wire when you catch it happens usually around 10mA (5 for small children). 

Even 100mA may be enough to stop your heart under right circumstances.

And even the current that won't kill you can cause involuntary muscle contraction which may lead you to touching something more dangerous at higher voltage/amperage, a hot soldering iron tip or something similarly pleasant.

If you don't know what you're doing it'd be best to not touch any electrics or electronics, especially with bare hands.

- Always unplug any electronics and electrics from electricity source - either by unplugging, taking batteries out etc.

- You need to know how capacitors look. Those will soon be described in a post about capacitors. They are like batteries in that they can store electric energy, but they can give it out really quickly, which means that even a capacitor smaller than an AAA battery can potentially kill you as it may very well have 200 or more Volts loaded inside and fire it in one powerful burst... 

- Do NOT touch circuit board on which there are electrolytic capacitors unless you checked their voltage or know they can't have high voltage. Because if they have, you can get shocked as they can be loaded with electricity long after the piece of equipment stopped being used.

- Discharge capacitors before touching them (more on safe ways of discharging them in capacitors post).

- Use insulating gloves unless you like it risky or know what you're doing - I don't, but I do know what I'm doing and I do like doing it risky... And I certainly would wear protective equipment for high voltages.

- Use insulated tools when working with any elements that may be dangerous and which you can't discharge safely (more on that too in capacitors post).

- Watch out with anything wet around electric and electronic equipment (especially that many soldering stations have a sponge for cleaning soldering tip which should be wet with water).

- Always keep your tools grounded when they require it - don't plug a tool needing grounding into socket without grounding, it may save your life if it accidentally gets shorted out.

- Remove any metal jewelery - rings, bracelets etc. when working with electrics and electronics - you'll reduce chances of shorting something out by accident.

* Explosions.

While the highest immediate threat is electricity, there also are elements that can explode or send tiny pieces damaging your skin or if you're unlucky hitting your eye possibly destroying it.

- Always wear protective goggles when working.

Accidentally overloading capacitors can lead to them boiling out or even exploding. Other parts can burn.

Capacitors also can sometimes explode when you short them out, so don't listen to idiots saying that to make it safe you need to touch both wires with insulated metal objects.

When clipping wires you can send piece of wire into your eye.

When soldering, solder (or rather its flux) or some impurities may sizzle and send molten metal into your eye...

There probably may be many other such situations. 

So always use protective goggles (possibly ones certified against high velocity fragments). I can't stress it enough.

If you use glasses normally, they could protect you a bit too, but keep in mind that they don't cover eye that well and aren't made to withstand those hits and cost a lot more than regular protective goggles...

* Toxic substances

- Solder used in soldering may contain up to 40% lead which is toxic when ingested. Do not eat it. Wash hands after soldering.

- Rosin (and possibly other kinds of flux) which is used in soldering, when heats up burns producing smoke which can be carcinogenic and otherwise unhealthy to breath in. Use a fume extractor, a fan blowing the smoke away from you, or at least do soldering in a well ventilated place (which should be the case even with fume extractor and/or fan).

* Fire hazard

With electricity there also always is a fire hazard. 

- Never play with electrics/electronics near something flammable. 

- Remove carpets, cardboards and such from proximity. 

- Watch where you place your soldering gun or iron - they may be at around 400 Celsius degrees (750 Fahrenheit) - enough to burn most plastics, wood, paper, set off many flammable substances.

- When wired incorrectly with too high voltage resistors may start burning, wires may start heating up, so always check if you placed all parts to the specifications...

- Don't connect too many cables to one wall socket - especially don't plug in an extension cord into another, don't use divider in divider etc. - their wires may heat too much, melt the insulation and short out causing a fire.

- Never leave unprotected (without casings, untested etc.) systems running unattended - if something goes wrong with no one to quickly react they could cause fire.

* General

- Always have a fire extinguisher, first aid kit and phone close to your workspace - never know when something could go wrong.

- Keep away all those dangerous things away from children and animals.

Thank you for attention, that's all for now.

I'm sure that more even more detailed points and explanations could be added, but those are most general and important ones - when there will happen other dangers along the way I for sure will write about them and about measures to avoid them in related posts.

Feel free to comment with any questions or if you think something I wrote is incorrect ;)

If you're curious about why I'm writing this blog and what it's all about, please visit the first post: Electronewbie Begins

Good luck, keep reading.

And do it with me ;)