Small gas canisters for portable stoves and outdoor camping can cause serious accidents if used inappropriately or when they deteriorate over time, warned a quai-government institute for industrial products ahead of Disaster Prevention Day on Monday.

According to the National Institute of Technology and Evaluation’s (NITE) statement on Thursday, a total of 204 accidents involving the use of gas canisters — which can be lifesavers in times of natural disasters — were reported between 2020 and 2024. These accidents caused five deaths and 67 injuries.

Of 157 cases that were closely studied by NITE, the most common cause of accidents was a faulty product, which accounted for 92 incidents, followed by misuse, at 29 cases. In seven cases, canister deterioration over time was identified as the cause of accidents.

In many of the cases, gas that leaked from the canisters caught fire.

To prevent such cases, NITE urged users to check expiration dates — typically 10 years from the manufacturing date. Users are also urged to verify that canisters are properly connected to stoves during use to ensure there is no gas leakage. It said gas canisters should be stored in places where the temperatures do not exceed 40 degrees Celsius.

NITE said there were also 21 reported accidents between 2020 and 2024 related to the use of portable power generators, most of them carbon monoxide poisoning as a result of indoor usage.

Of the 17 cases it investigated, 12 occurred as a result of mishandling. Accidents involving portable generators tend to have multiple victims. In the five years through 2024, six deaths were tied to mishandling of portable generators.

To prevent such accidents, NITE said such generators should only be operated outdoors where there is good ventilation.

In disaster-prone Japan, both gas canisters and portable generators can be useful to have on hand as they enable people to cook food or use heaters during cold seasons as well as allow the use of electrical appliances.

NITE said it is important for people to not just purchase these tools but also learn how to use them properly to prevent accidents.

Users should also keep themselves updated in the event that certain products are being recalled due to defects or because they have become outdated, it said.