HMRC has announced that supplies of certain types of Personal Protection Equipment (PPE) will be zero rated for a short period. It does not matter whether VAT was paid on the purchase of the PPE, a supply of qualifying PPE taking place between 1 May 2020 and 31 July 2020 is zero rated.
Qualifying PPE includes:
Disposable plastic aprons
Disposable fluid-resistant gowns
Filtering face piece respirators
Eye and face protection
For more details see https://www.gov.uk/government/publications/revenue-and-customs-brief-4-2020-temporary-vat-zero-rating-of-personal-protective-equipment-ppe/revenue-and-customs-brief-4-2020-temporary-vat-zero-rating-of-personal-protective-equipment-ppe
Note that in some circumstances PPE can be imported free of import VAT, see https://www.gov.uk/guidance/pay-no-import-duty-and-vat-on-medical-supplies-equipment-and-protective-garments-covid-19?utm_source=52409243-3ef0-47c4-9c33-77bd38562ddb&utm_medium=email&utm_campaign=govuk-notifications&utm_content=immediate