It is an open question whether that is really a safe long term limit, as these things do tend to accumulate in the body.
Soylent 1.5 has 21.39g (.021 mg) of cadmium per 500 calorie serving.
So, as per the EPA standard, if that person ate mostly soylent, 4 servings per day (2000 calories), you would have
Note the definition of mg/kg/day is how many mg of something you can consume per kg of body mass. The soylent guy's google spreadsheet reports mg/kg of the toxic substances in the soylent itself, which is irrelevant. This suggests that he doesn't understand what he is talking about. What a surprise.