Electrolytic Removal of Rust - A Detailed Illustrated Tutorial, page 40
10. Safety Precautions in Electrolysis
1) Dangerous Levels of Voltage and Current
As it was stated in the "Controlling Voltage and Current" section on page 23, in electrolysis, voltages above 24 volts are not productive. And in general, a voltage of less than 32 volts is not hazardous to the human body.
So the voltage of an electrolytic setup is not of any concern unless one makes a terrible mistake by using "wall current" (the current that comes from a wall socket, also called household power, household electricity, house current, powerline, domestic power, wall power, line power, AC power, hydro (in Canada), etc.), or any type of mains current for electrolysis - 110 or 220 volts will kill anyone in a flash!
DC CURRENT should be taken seriously because hazards of human exposure to electricity depend more on the current than the voltage. And the current resulting from a given voltage depends on the human body's resistance. If one's hands have unbroken, dry skin, their resistance is tens of thousands of ohms, and little or no current would pass through the body.
But if the skin is punctured or wet, the body resistance can be as low as one thousand ohms. In this case, if one holds an electrode in each hand, and sticks the hands in electrolytic solution for a while, even the low voltage of 10 to 15 volts could allow a dangerous level of current to flow across the human body. Usage of high DC power supplies such as a DC welder to get faster results MUST be avoided!
Even a low current flowing through the human body may develop a reaction hazard caused by involuntary reaction to a mild shock. It can be a safety problem if reaction causes striking, falling, dropping, losing control, etc. Higher current can cause ventricular fibrillation or tissue damage resulting in injury or death. Typically it takes 10 or more milliamps driven through the body to start causing problems.
2) Avoid Being Electrocuted
To avoid electrical hazards to your body, which are described above, follow these simple rules:
1) Always wear protective rubber gloves
2) Always turn off the power before making adjustments to the setup. Do not touch electrolyte, electrodes and iron objects being derusted with bare hands at the same time when power is applied, otherwise you will receive a mild shock.
3) Do not use an unregulated power source such as a car battery. Use only a power supply with a current limit that can be regulated. A car battery charger best serves the purpose.
4) Avoid using a metal vat as both the container and the anode. It is easy to have an accidental contact and get electrocuted while working around a large-sized electrically "live" component of the electrolytic setup.
3) Avoid Short Circuiting
If a power source for electrolysis does not feature any protection against short-circuiting, accidental short-circuiting can cause an irreversible damage to the power supply and a hazardous reaction of human body. To avoid short-circuiting, follow these safety rules:
1) Place anodes and iron objects being derusted in the container properly, so that they would not come loose or fall on each other. For details read the "Placing Electrodes in Electrolyte Properly" section on page 19, and "Placing Artifacts in Electrolyte Properly" section on page 21.
2) Do not place a car battery charger (or whatever source of power you use) too close to the electrolytic setup to avoid accidental spills onto the battery charger. Also keep the battery charger indoors while the setup is placed outdoors. If the battery charger is placed outdoors, cover it to protect from moisture (rain, snow or lawn watering), and apply all of the usual cautions about operating any electrical device in a wet environment.
4) Protect Your Eyes and Skin
Washing and baking soda electrolytic solutions are alkaline and, although not considered dangerous, will irritate the skin and eyes. Prolonged contacts with the skin should be avoided, and the electrolyte must be kept away from the eyes. Also keep in mind that many other contaminants, especially toxic ones such as hexavalent chromium when stainless steel is used for anode (see details on page 9), may get into the electrolyte and cause health problems. It is probably best to use a minimum amount of stainless material, and if it is used, certainly wear protective gloves when working in the electrolyte.
When the electrolyte gets onto your eyes, immediately wash it off with lots of water, and if any pain does not go away, seek medical attention. To avoid problems, wear protective gloves and safety glasses all the time during electrolysis. Also wear cloths that fully cover your body.
If you use acid or lye for the electrolyte, you MUST protect your eyes with protective goggles and your skin with a full face shield. If you get acid or lye in your eyes you can be blinded! It is best not to use harmful chemicals at all. Remarkable results in electrolytic derusting can be easily achieved with just regular baking soda.
5) Avoid Toxic Gas Danger
There are two cases of toxic gas release during the electrolysis:
1) when TABLE SALT is used to prepare the electrolytic solution, and vapors of Chlorine gas is produced during the process (see details on page 15). Chlorine gas can make you really sick quickly.
2) when STAINLESS STEEL anodes are used, and Hexavalent Chromium gas is released in the mist directly above the electrolytic bath (see details on page 9). Long term inhalation of these fumes increases the risk of lung cancer. If you do not conduct electrolysis daily over a long period, you would not be exposed to levels that should cause immmediate concern.
To avoid toxic gas danger, it is probably best not to use salt at all, and use only a minimum amount of stainless material with adequate vetilation and/or breathing protection. And NEVER put your face directly above the electrolytic container!
6) Prevent Accumulation of Explosive Hydrogen and Oxygen Gases
When electric current flows through the electrolyte, hydrogen gas is evolved at the cathode, and oxygen gas is evolved at the anode(s). When ventilation is absent or inadequate, and hydrogen and oxygen gases are mixed at high concentration levels, a highly flammable and explosive mixture is produced. A single spark between a power clamp and an electrode can produce a violent explosion. The fire of explosion burns at about 4280 °F (2360 °C) and may seriously injure you.
To prevent accumulation of explosive hydrogen and oxygen gases, do the following:
1) Ensure the electrolysis is conducted in a very well ventilated area or better - outdoors, so that the gasses can escape safely.
2) NEVER cover the electrolytic bath with a tight lid, otherwise gas pressure and high concentration levels of gases will build up.
To avoid any risk of explosion, do the following:
1) ALWAYS turn off the power before making adjustments to the setup.
2) Keep ALL potential sources of ignition (flames, cigarettes, torches, etc.) away from the top of the tank and surrounding area.
3) If you have already run an electrolysis session indoors, and need to run another session, do not "crank up" the process - wiggle the cathode to get a spark and establish a good contact (see details on page 22), before you completely ventilate the area.
7) Keep an Electrolysis Setup Undisturbed
Electrolysis should be conducted in a designated place which must meet the following conditions:
1) It must be away from human traffic so that no accidental contact can occur.
2) It has no access by animals, pets, children, or those who do not understand the danger.
3) An outdoors setup should be protected from stray and wild animals, falling branches and leaves, and strong winds.