Latest News: Our Annual Review is now live. Read the HTA Annual Review 2022

Find out more!
Plant image

OHAS - UK & Internationally Accredited

OHAS standards are specifically designed to meet the needs of the horticulture industry whilst being aligned to international standards. 

Quality Assurance - specific not generic

OHAS is the only certified scheme in the UK solely relevant and dedicated to ornamental horticulture. Unlike other generic quality schemes, OHAS Standards are specifically designed to meet the specialist needs of the industry. They are managed by a dedicated team which means the standards are designed for and react to specific technical and legislative requirements within the horticulture industry.  In the last year, the OHAS Standards were strengthened in relation to plant health initiatives and biosecurity.  

A Certified Scheme which is UK and internationally recognised

The Scheme assesses organisations through annual, independent audits carried out by a UKAS accredited body (NSF Certification Ltd) against internationally recognised criteria.

You can be assured that OHAS certified members meet and operate their businesses at the highest standards required by UK and international marketplaces. They are up to date with the latest legislation and best practice in the horticulture industry and committed to continuous quality improvements across their business.

The OHAS Standards are benchmarked to GLOBALG.A.P International Farm Assurance (IFA) Version 5.2, Flowers and Ornamentals and are regularly reviewed and updated.

The OHAS Grower Standard Version 4.0 (July 2021) has ‘resembling status’ and growers can choose an additional module to give them full GLOBALG.A.P IFA certification equivalence.  From 2023 the intention is that the additional module will be incorporated fully into the Standards meaning all OHAS Certified growers will have full GLOBALG.A.P equivalence certification.

The OHAS Packhouse Standard Version 6.2 (July 2021) is currently within the FSI (Floriculture Sustainability Initiative) basket. It has recently been updated to ensure its content is fully aligned with the OHAS Grower Standard Version 4. This makes it the choice of quality assurance standard for sites which are both growers and packhouses.

Clear Plant Health and Biosecurity Alignment

The ethos of plant health and biosecurity is core to the OHAS Standards, and the Grower Standards are significantly aligned to plant health initiatives.

OHAS is a complete, robust, business management QA type scheme incorporating a wide scope of best practice.  It includes business management, health and safety, plant health, sustainability, the environment, staff management and welfare and much more.

OHAS & Plant Healthy Certification Scheme FAQ


Describing how the Plant Healthy Certification Scheme standards will work with OHAS.

OHAS Certification Partner - NSF Certification

A UKAS accredited certification body who audit the Grower, Packhouse and Growing Media Standards.

Contact NSF to book an audit/inspection at or call 01993 885610.

OHAS Certification Partner - ADAS

An inspection body who inspect against the Continual Development Standard and provide a scored audit with advisory comments that will help businesses to improve their performance each year.

Contact Donna Jacklin to book an inspection at or call +44 (0) 1954 268201.