SEOUL, March 1 (Reuters) - South Korea tightened rules

on carrying lithium batteries on planes from Saturday,

highlighting a growing risk to flights worldwide from the

batteries used in cellphones and e-cigarettes which can

malfunction to produce smoke, fire or extreme heat.

Last year three incidents a fortnight of overheating lithium

batteries on planes were recorded globally by the U.S. Federal

Aviation Administration, compared to just under one a week in

2018.

Aviation has long recognised the increasingly used batteries

as a safety concern, and rules are periodically tightened in

response to accidents.

From Saturday, passengers on South Korean airlines should

keep power banks and e-cigarettes on their person and not in

overhead cabin bins. Devices should not be charged on board, and

battery quantity and strength limits will be enforced.

Passengers will be permitted to carry up to five

100-watt-hour portable batteries, while batteries over

160-watt-hours won't be allowed on board. The batteries will

also need to be stored in clear plastic bags, according to the

transport ministry.

South Korean travellers flying out of Incheon

International Airport, the country's largest airport, told

Reuters on Saturday that they were "relieved" by the new rules.

"I feel safe since we have new guidelines that can

protect us. I was also advised to carry (these batteries) with

me when I'm on board, that makes me feel relieved that we can

find out immediately when something happens," said 37-year-old

Kim Jae-woung.

Korean authorities said the measures were in response to

public anxiety about fires after an Air Busan plane

was consumed in flames in January while waiting to take off.

Investigators have not yet determined the cause of the fire,

but a preliminary investigation statement on Thursday said it

started in a cabin overhead locker after boarding.

All 170 passengers and six crew were evacuated before the

aircraft was destroyed. The fire was detected around 20 minutes

after the delayed flight had originally been scheduled to

depart.

"Existing cabin crew firefighting procedures have been

demonstrated to be effective for all (lithium battery) incidents

which have occurred in-flight. However if such an incident

occurs while on the ground, the safest option is to evacuate the

aircraft," a spokesperson for the International Air Transport

Association said.

Cabin crew are trained to put out flames with extinguishers,

cool the battery with liquid, and isolate the device in fire

containment pouches or boxes.

HUNDREDS ON EACH PLANE

Lithium metal and lithium-ion batteries are types of

non-rechargeable and rechargeable batteries found in devices

such as laptops, mobile phones, tablets, watches, power banks

and electronic cigarettes.

Passengers on a full flight could be carrying hundreds

between them.

Manufacturing faults or damage, such as a phone being

crushed in the gap between plane seats or exposed to extreme

temperatures, can cause them to short circuit and rapidly

overheat.

Heat, smoke and fire can result, and they can even explode

in a "high-energy expulsion of extremely hot gel and parts of

the device acting as shrapnel", the Flight Safety Foundation

says.

In 2016, U.N. aviation agency ICAO banned passenger planes

from carrying lithium batteries as cargo. This followed fatal

crashes of a UPS freighter in Dubai in 2010, and an

Asiana Airlines cargo plane in South Korea in 2011,

after intense fires broke out in holds carrying such batteries.

Current aviation standards say power banks and personal

electronic devices should travel in the cabin, not in checked

luggage, so any malfunction can be tackled.

A December 2024 research report by the European Union

Aviation Safety Agency (EASA) found that "non-compliant lithium

batteries persistently travel in hold baggage", and that hold

baggage screening need to be improved.

The industry is exploring new detection methods, including

the use of scent detection dogs.