A police cordon has been in place on Lipson Road since the early hours of Friday 21 February.
The police are desperately seeking two suspects in connection with the acid attack but have still not provided a description of the suspects.
Police have now confirmed that acid was used during the attack to inflict the injuries.
Plymouth Plus understands that the victim who was targeted is in a serious condition and has been transferred to a specialist burns facility.
DCI Lee Nattrass said:
"We are treating this as a targeted attack and there is no wider threat to the community.
Residents may have seen an increased police presence in Lipson Road as we have continued to investigate the incident. Our enquiries remain ongoing."
Anybody with any information or relevant CCTV or dashcam footage is asked to contact police on 101 or via our website quoting log 69 of 21 February.
