If a customer asks for a little of your tank mix and hands you an empty glass jar, it is alright for you to give him some as long as you warn him carefully.

The answer is based on safety protocols and regulations surrounding the handling of chemical substances. Providing a customer with any amount of your tank mix, even with a warning, is considered inappropriate and unsafe. Tank mixes often contain pesticides or other hazardous chemicals that could pose serious health risks if they are not handled properly.

It is important to adhere to strict guidelines to prevent accidental exposure or misuse of the product. Both the potential for toxicity and legal responsibilities reinforce the need to never provide any unlabelled or uncontrolled substances to customers. Furthermore, there are likely specific regulations preventing any distribution of pesticides outside of their intended, properly branded containers. Therefore, it is critical to refuse such requests to ensure safety and compliance with the rules governing pest control practices.