Looking at the chart you can see, if an oil has any appreciable measure of Omega-3 fatty acids in it, it is rated as an omega-3 oil. Chia seed actually has a little higher ratio of omega-3 than even flax seed.
The safflower, cotton seed and corn seed oils look have similar make up as the sunflower seed oil in the chart. These are major omega-6 oils, or ‘shelf-life’ oils, that food manufacturers use profusely. They are the primary reason why 20% of the population has levels of omega-3s so low that they defy detection.