Reviewers set no daily limit
The international expert committee and European reviewers have both looked at malic acid and found no basis for a numerical daily limit. The body already handles a lot of it, from fruit and from its own chemistry.
The international committee found nothing that called for a numerical daily limit, and said intake from permitted food use is far below any level of concern.
Regulator reviewJECFA (Joint FAO/WHO Expert Committee on Food Additives)
European reviewers looked again at malic acid and its salts (E296, E350, E351, E352), kept them approved with no numerical daily limit, and saw no evidence of harm at normal levels.
2013Regulator reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), re-evaluation opinion
Like any food acid, it can wear down teeth
Malic acid adds to how acidic a food or drink is. Teeth that are often bathed in acidic food and drink are linked to worn enamel. This is true of acidic food in general, not malic acid in particular.
Studies that observed people found that often having acidic fizzy drinks and sour sweets, which usually contain malic or citric acid, is linked to worn tooth enamel.
ObservationalCochrane systematic review on erosive tooth wear; multiple dental epidemiology studies