The bill titled SF No 319 introduced in the Minnesota Senate proposes to establish specific penalties for individuals who knowingly mix or replace controlled substances or drugs with fentanyl. The key points of the proposed legislation are:

1. It will be considered a felony crime to deliberately adulterate or alter a controlled substance or drug by adding fentanyl, or to substitute the original substance or drug entirely with one containing fentanyl.

2. Similarly, a felony charge will also apply to those who knowingly replace the controlled substance or drug in any package or container with fentanyl, or swap the entire package or container with one containing fentanyl.

3. However, exemptions are provided for professionals such as manufacturers, practitioners, pharmacists, pharmacy owners, nurses, and others, when they are acting within their professional capacities.

4. Important terms used in the bill like "controlled substance" and "drug" are defined according to specific sections of existing Minnesota statutes.

In essence, the bill is aiming to criminalize the act of tampering with controlled substances or drugs by introducing or substituting them with fentanyl, with exceptions made for professionals carrying out their duties legally.