As an expert in clean beauty and skincare, I can provide you with some insights into the shelf life of tea tree oil. Tea tree oil, derived from the leaves of the Melaleuca alternifolia plant, is known for its antimicrobial and anti-inflammatory properties.

When it comes to the expiration of tea tree oil, it's important to note that essential oils, including tea tree oil, do not have a specific expiration date like food products. However, they can degrade over time, resulting in a decrease in their effectiveness.

The shelf life of tea tree oil can vary depending on several factors, including the quality of the oil and how it is stored. Generally, if stored properly, tea tree oil can last for about 1-2 years. However, it's essential to consider the following guidelines for optimal storage:

1. Store in a cool, dark place: Exposure to heat and light can accelerate the degradation of tea tree oil. It is best to store it in a cool, dark place away from direct sunlight.

2. Keep the bottle tightly sealed: Oxygen can also contribute to the deterioration of tea tree oil. Make sure the bottle is tightly sealed when not in use to minimize exposure to air.

3. Avoid contamination: To prevent contamination, use clean hands or tools when handling the oil. Avoid touching the dropper or bottle opening with your fingers to prevent introducing bacteria.

4. Check for signs of degradation: Over time, tea tree oil may lose its potency and develop a rancid smell. If you notice any unusual odor or changes in color or consistency, it's best to discard it.

Remember, these are general guidelines, and the quality of the tea tree oil and storage conditions can affect its shelf life. If you're unsure about the freshness or efficacy of your tea tree oil, it's always best to replace it to ensure optimal results for your skincare routine.