Here's the buzz about mosquito repellents

Ayra Wang

Consumers are urged to look at the ingredient label carefully when choosing mosquito repellents as the Consumer Council found that one sample with natural ingredients attracts mosquitoes while those with DEET and picaridin provide the best long-lasting protection.

The consumer watchdog tested 25 mosquito repellents on the market, with prices ranging from HK$18.9 to HK$259 per bottle. It found that eight out of nine formulations containing DEET and picaridin can maintain 80 percent or more protection for four hours after application against both the southern house and yellow fever mosquito.

The most effective repellent was 3M's Ultrathon Insect Repellent Lotion, boasting a DEET concentration of over 30 percent, as no mosquito landed on the tester's forearm after application during the four-hour test.

However, council chief executive Gilly Wong Fung-han said at a press conference yesterday that people should also be aware of possible skin rashes, blisters and irritation after being exposed to a high concentration of DEET.

She also urged people not to apply DEET-based repellents on infants and use low-concentration products for kids as DEET may pose a higher risk to children.

"The Centre for Health Protection of the Department of Health has recommended children use mosquito repellents with 10 percent DEET concentration at most," Wong said.

"Infants under six months should not use products containing DEET unless they are traveling to countries or areas where mosquito-borne diseases are endemic and exposure is likely."

Wong said picaridin irritates skin less than DEET but people still need to be careful not to get it into their eyes.

The performance of formulations with other ingredients, such as IR335, PMD and tomato extract, varied. Two containing wild tomato extract provided only 16 percent and 26 percent repellent efficacy for 30 minutes after application.

Eight claiming to contain natural ingredients provided satisfactory protection against the southern house mosquito while performing poorly against the yellow fever mosquito.

One formulation, Cherub Rubs Scatterbugs, was even found to be attractive to mosquitoes. Its manufacturer has stated the product primarily serves as a safe outdoor moisturizer and only provides a short mosquito repellent effect.

Wong suggested citizens choose mosquito repellents according to their needs and those allergic to certain ingredients should consult their doctor before buying.

Meanwhile, the council also warned parents to avoid baby clothes with long decorative items that are prone to having small parts fall off as they may pose safety risks.

It tested 30 pieces of baby clothing supposedly suitable for babies aged two or below and found 11 models with snaps or buttons that detached during tension tests, which pose a choking hazard if swallowed. The cord design of five models failed to comply with European standards and poses a risk of strangulation.

The council suggested parents wash baby clothes before use to remove allergenic chemicals as one model was detected with 32.3 mg/kg of free formaldehyde, which exceeds safety standards and may irritate babies' skin, and 10 models had brighteners that may cause skin allergies.

ayra.wang@singtaonewscorp.com