The WHO said it was collaborating with both the manufacturer and regulatory authority in South Africa to investigate the Benylin paediatric syrup, and had information on the source of the ingredients used. Kenvue has previously said it tested its ingredients before manufacture.
The agency said the possibility that the syrup was counterfeit was also "under consideration as part of investigations".
Earlier this week the WHO sent out a separate alert on five batches of contaminated cough syrup ingredients found in Pakistan that appeared to have been falsely labelled as Dow Chemical products.
It was the first alert the WHO has sent on excipients - elements of a medicine other than the active pharmaceutical ingredient - rather than finished products, the agency confirmed on Friday.
The batches of propylene glycol were contaminated with ethylene glycol.
"It was critical for WHO to also alert manufacturers that may have been procuring this material to exercise more caution," a WHO spokesperson said by email.
Propylene glycol is not an ingredient in Benylin paediatric syrup, a Kenvue spokesperson said on Friday.
