Hi, I used parve garlic and oil with a parve immersion blender inside of a meat plastic container. Is the immersion blender now fleishig? and does the garlic also render other items fleishig, like a spatula used to get the garlic and oil out of the container?
No, the blender and other utensils will remain pareve.
Although the plastic container is meaty, its taste will only be imparted to the garlic and from there (possibly) to the utensils by means of pressure (like a knife cutting through garlic) or if the garlic is hot.
If nothing is actually hot, the garlic will not become meaty, and neither of course will the utensils.
Even if the garlic becomes meaty, this will not necessarily mean that the blender will become meaty, as we have explained here and other places.