In a comprehensive study aimed at supporting Hong Kong’s growing “eco-friendly” lifestyle, the Consumer Council has tested 18 popular travel mugs and portable tumblers. The results, published in the latest issue of CHOICE magazine, highlight a massive disparity in performance regarding temperature retention, leak-proofing, and stability. While consumers increasingly carry reusable vessels for coffee and tea to reduce plastic waste, the Council warns that price and brand do not always guarantee functionality, with several high-end models failing basic spill tests.
Performance Leaders in Temperature Control
The Council’s rigorous testing focused on 18 models sourced from coffee shops, department stores, and online retailers, ranging in price from HK$80 to $425. Following European testing standards, vessels were filled with 95°C water and monitored over six hours. Only two models managed to keep liquids above 60°C: the STANLEY (63.8°C) and the NOC (60.8°C). Notably, the NOC achieved this despite its smaller 354ml capacity, making it a highly efficient choice for those preferring smaller beverages.
Other reputable brands, including Starbucks, ZOJIRUSHI, and WOKY, maintained temperatures above 50°C, a standard considered satisfactory for most commuters. Conversely, plastic-based models performed poorly, with water temperatures dropping to near-room levels (26°C–29°C) after six hours, rendering them ineffective for heat retention.
Safety Risks and Leakage Flaws
Reliability in a bag is a primary concern for “bring-your-own-cup” enthusiasts. The report revealed that 12 of the 18 samples remained completely bone-dry when inverted for one hour, including models from MUJI, 24BOTTLES, and RICOCAFE. However, six prominent brands—including THERMOS, STANLEY, and ZOJIRUSHI—exhibited leakage when held upside down.
The testing team also identified a specific stability issue with the popular STANLEY tumbler. Due to its top-heavy design, narrow base, and heavy handle, the mug proved prone to tipping over when placed on a slight 10-degree incline, regardless of whether it was empty or full.
Capacity Discrepancies and Material Safety
Another critical takeaway involved labeling accuracy. The Council found that 14 models provided less internal volume than advertised. Five brands, including MUJI and DECATHLON, showed a discrepancy of over 10%, failing to meet European standards for “nominal capacity.” In contrast, NOC and Starbucks were among the few providing the exact volume stated on the packaging.
On the safety front, the news was largely positive. While trace amounts of heavy metals such as nickel and chromium were detected in some stainless steel liners during acid-leaching tests, the levels remained well within international safety limits and posed negligible health risks under normal usage.
Guidelines for Safe Daily Use
To assist local foodies and coffee lovers, the Council suggests choosing a vessel based on lifestyle: small stainless steel mugs for short commutes and vacuum-insulated tumblers for long-duration temperature maintenance. Users are cautioned against fillling mugs with carbonated beverages, which can cause pressure build-up, or herbal drinks like red date tea, which can ferment and lead to explosive lid release. Regular deep cleaning of silicone seals is also recommended to prevent bacterial growth and ensure a long-lasting, sustainable hydration experience.