South African households and businesses are using generators to keep the power on amid the country's worsening load shedding crisis. These users need to take extra care.

Back-up power produced by petrol and diesel generators has become popular, especially among businesses, amid Eskom's inability to supply the country with stable electricity. South Africa was plunged into Stage 6 load shedding on Tuesday – set to return on Wednesday evening – because of unexpected breakdowns, routine maintenance, and, more recently, a strike by disgruntled plant workers.

This heightened stage of load shedding has seen South Africans rush to retailers and hardware stores in search of alternative energy products. Candles, paraffin, gas bottles, emergency lights, and rechargeable lanterns are some of the essentials for home use, but businesses with higher energy demands turn to more powerful solutions.

These solutions include Uninterrupted Power Supply (UPS) products, solar panels, and invertors. Electric generators are favoured because they don't need time to charge, producing power as long as they're fuelled, don't rely on the availability of sunlight, as is the case with solar power, and are strong enough to power a number of critical appliances that businesses rely on to operate.

Generators do have drawbacks. For starters, they're loud. The price of fuel, at record-high levels, adds to the running costs, as does regular maintenance.

Operating generators, which convert fuel into power through combustion, also requires a higher degree of vigilance compared to other alternative energy solutions.

Here are critical instructions for the safe use of generators at home or at a business, according to the American Red Cross and Centres for Disease Control and Prevention (CDC).

Carbon monoxide is a colourless, odourless, toxic gas emitted by burning fuels. The worldwide cumulative incidence and mortality of carbon monoxide poisoning are currently estimated at 137 cases and 4.6 deaths per million, respectively.

Electric generators, by burning petrol or diesel, emit carbon monoxide. That's why it's critical that generators are never used in an enclosed, or even partially enclosed, space, like a home, garage, or basement. Opening windows or doors to ventilate the enclosed area is not sufficient and may not prevent carbon monoxide from building up.

Additionally, generators should not be used near windows, doors, or vents, even when outside. The CDC recommends placing the portable generator in an open area at least six metres from any window, door, or vent.

Portable generators should never be used in wet weather. Rain seeping into the generator's outlets or engine could result in electrocution or even an explosion. Some generators, with their own enclosures, can be safely operated in rainy weather, but only if explicitly stated by the manufacturer.

Appliances in need of electricity during a power outage should be plugged directly into the generator. Generators should never be used to power an entire home or business through a back-feed, which is the practice of connecting to an electrical outlet with a modified extension cord that has two male pronged plug ends.

Back-feeding energises the entire circuit via the outlet and creates a dangerous fire hazard. Because this practice pumps electricity back into the grid, it presents a serious shock hazard for utility workers operating in the area, too.

Fuel is used to power the generator, which in turn produces electricity. Because of its flammable nature, this fuel needs to be stored in an approved safety can, outside of living areas, and away from fuel-burning appliances like the generator itself.

Refuelling should only be done when the generator has had time to cool down. Fuel spilt onto a hot engine can ignite.