The Ugly Truth Of PLA Straws : Why Are They Harder to Decompose Than Plastic Straws ?

In recent years, with the rise of global plastic reduction awareness, many businesses and consumers have started switching to PLA straws, which are claimed to be "biodegradable." This type of plant-based straw, made from agricultural waste like cornstarch or sugarcane, sounds eco-friendly and benign and seems to be the ideal solution for plastic pollution. However, did you know that, in many situations, the difficulty of decomposing PLA straws might be higher than that of the traditional plastic straws you imagine, potentially making them another hidden source of pollution ?

Today, we will delve into the "ugly truth" of PLA straws, exposing their decomposition dilemma across various global regions, and explaining why this "eco-friendly" option may not be as good as it seems on the surface.

The Trap of "Biodegradable" : Requires Industrial Composting

To understand the problem with PLA straws, one must first clarify the term "biodegradable." It does not mean, as many imagine, that the product will break down on its own when discarded in the natural environment. The definition of biodegradable plastics according to international standards (such as EU EN 13432 or US ASTM D6400) refers to breaking down in a specific and strict industrial composting environment.
At High temperature(usually requires reaching 58°C or above), high humidity(usually requires reaching over 80%), and under the action of specific microorganisms, where they decompose into carbon dioxide, water, and biomass within a period (usually 90-180 days).

Key Takeaway : This decomposition process is called "Composting." If these precise conditions are lacking, PLA straws cannot decompose effectively.

The Chemical Nature of PLA : "OTHERS" in a Plant-Based Disguise

PLA (Polylactic Acid) Although the raw materials come from renewable agricultural waste, such as cornstarch, sugarcane, or cassava, making it a typical "Bio-based Plastic," these plant sugars are converted into polylactic acid polymer through chemical processes like fermentation and polymerization.

Key Takeaway : Despite the natural raw materials, PLA's molecular structure is already a polymer after polymerization. In many countries worldwide, PLA is usually classified as OTHERS . This means that it does not belong to the six major categories of common plastics like PET, HDPE, PVC, LDPE, PP, and PS, and requires independent handling in recycling classification.

The Practical Challenge : Lack of Industrial Composting

Theoretically, PLA straws should be sent to specialized industrial composting facilities for processing. However, this is precisely the biggest challenge commonly faced across all regions worldwide:

• Facility Scarcity : In many regions worldwide, industrial composting facilities capable of processing PLA straws are extremely scarce and not yet widespread. The waste disposal systems in most cities are still primarily based on incineration and landfilling.
• Collection Difficulty : Even if facilities exist, PLA straws need to be sorted separately from general waste to enter the composting process. But in real life, consumers often find it difficult to correctly identify and sort PLA, leading to it often being mixed into general waste or traditional plastic recycling.

International Regulations and Restrictions : Many Countries Are Saying No to PLA Tableware !

Due to the decomposition and recycling difficulties mentioned above, more and more countries and regions worldwide have begun to seriously address the issue of PLA tableware and are gradually implementing restrictions or bans.
This highlights that PLA is not a foolproof plastic substitute :

• European Union(EU)： Since July 2021, the EU's Single-Use Plastics Directive (SUPD) has banned various single-use plastic products, including plastic cutlery, plates, and straws. Although the directive primarily targeted traditional plastic, its spirit is to promote reusable and truly decomposable alternatives. Many member states have consequently adopted a stricter attitude towards "biodegradable" plastics like PLA, believing that they do not effectively solve the problem of plastic pollution. Furthermore, some EU member states have specifically restricted their scope of use.
• Taiwan： 台灣環保署也已在2023年將 PLA餐具 認定為塑膠免洗餐具，並從當年8月起，在公部門、學校、百貨公司、量販店、超級市場、連鎖便利商店、連鎖速食店、有店面餐飲業等八大場所，不得提供 PLA 材質的杯、碗、盤、碟、餐盒，逐步啟動對 PLA 產品的限制。
• 其他國家/地區： 許多國家、城市或地區也陸續對一次性塑膠（包括某些「生物可分解」塑膠）實施禁令，原因多半是其難以有效回收或分解，且在自然環境中仍會產生塑膠微粒。這表明全球對於「生物可分解」塑膠的實用性與環境效益，正進行更為嚴謹的審視。

比傳統塑膠更難處理的尷尬：回收與分解的雙重困境

當 PLA吸管 無法進入工業堆肥設施，也無法被正確回收時，它的命運往往是：

• 干擾傳統塑膠回收： 如果 PLA吸管 被誤投到傳統塑膠（如PET、PP）的回收管道，由於其化學結構和熔點與傳統塑膠不同，它會成為回收鏈中的雜質，降低回收材料的品質，甚至可能導致整批回收物報廢，造成更大的資源浪費。
• 掩埋場的假分解： 在缺乏高溫、高濕度和特定微生物的垃圾掩埋場中，PLA吸管的分解速度極其緩慢，幾乎與傳統塑膠無異。它會長期存在於環境中，在物理風化作用下，仍然會碎裂成難以察覺的microplastics ，持續對環境造成污染。諷刺的是，它雖然號稱生物可分解，但在實際處理上，反而比有明確回收管道的傳統塑膠更令人頭痛。

重新思考「環保」的定義：尋找真正的塑膠替代品

PLA吸管的案例提醒我們，「生物可分解」的標籤並非萬靈丹。真正的環境永續，需要考量產品的整個生命週期，從原料、生產、使用到最終的處理。

當我們尋求塑膠替代品時，應更注重那些：

• 真正能回歸自然： 在一般自然環境（如土壤、水體）下即可無害分解，不產生塑膠微粒。這類材料通常是未經高度加工的純天然無添加有機質。
• 製程單純： 無須複雜的化學加工或化學添加，降低生產過程的環境足跡與潛在毒性。
• 可重複使用或一次性但無負擔： 鼓勵優先選擇可重複使用的環保餐具；若為一次性需求，則應選擇能真正融入自然循環、不留下痕跡的材料。

For example, 蒲草吸管就是一種符合這些標準的純天然無添加植物吸管。它直接源自天然水生植物，無須複雜加工，使用後也能在自然環境中分解，真正實現「取之於自然，還之於自然」的環保理念，為我們提供了更理想的環保餐具選擇。