All compostable plastics are biodegradable but not all biodegradable plastics are considered compostable. According to international standards (ie. ASTM D6400, EN 13432), for plastics to be certified as ‘compostable’, they need to disintegrate within 3 months and biodegrade at least 90% within 6 months in an industrial composting facility environment. Once broken down, the material must not leave behind toxic residue.
所有可堆肥塑料都屬於可生物降解類，但並非所有可生物降解嘅塑料都可被堆肥。 根據國際標準，要被認證為「可堆肥」嘅話，塑膠一般需要係6個月內係工業堆肥設施環境中至少90％被生物降解。 分解後不能留下任何有毒殘留物。
Despite the friendly sounding label, compostable plastic will only biodegrade under specific circumstances. For instance, heat is a major factor in the ability for compostable plastic to undergo biodegradation, therefore it’s not suitable for home composting. It is also tricky to recycle - although some recyclers accept compostable plastic for recycling while many consider it a contaminant that compromises the recycling stream. However, in reality, a great share of compostable plastic is neither composted, nor recycled because disposal instructions are often not clearly communicated to end users, and there simply isn’t enough commercial composting infrastructure and programmes (none in Hong Kong🇭🇰!) to collect organic food scraps mixed with the new generation of compostable products.
雖然有個聽落好環保嘅標籤，但可堆肥塑膠只可係特定環境下進行生物降解。 比如熱嘅溫度🌡係影響可堆肥塑料生物降解能力嘅主要因素，所以一般不適合於家庭堆肥。 呢款塑膠回收起來也比較棘手，一D回收商會接受可堆肥塑料，但大部分認為佢物料不同會污染回收源。 然而實際上大部分可堆肥塑料都冇被送去堆肥或回收，因為丟棄說明不太明確，根本冇足夠嘅商業堆肥設施(至少香港冇啦) 嚟收集食物廚餘同新一代嘅可堆肥產品。