ISO 45001 or MASE: which health and safety certification to choose?

For a company that wants its command of occupational health and safety recognised, two paths dominate in France: the international standard ISO 45001 and the MASE scheme (Manuel d’Amélioration Sécurité Santé Environnement des Entreprises — the French companies’ safety, health and environment improvement manual). The two overlap heavily in substance; yet they do not tell the same story to the same audiences. Here is what you need to choose knowingly — or to decide to hold both.

Two logics, two origins

ISO 45001 is an international standard published in March 2018 by ISO, succeeding the OHSAS 18001 scheme. It sets the requirements of an OH&S management system following the structure common to the major management standards (clauses 4 to 10): context, leadership and worker participation, risk-based planning, operational control, performance evaluation, continual improvement. Certification is issued by accredited certification bodies (AFNOR Certification, Bureau Veritas, SGS, among others) for a three-year cycle with annual surveillance audits. Our guide to obtaining ISO 45001 certification details each step.

MASE is a French association-run scheme, carried by a network of local associations covering the country. Born in heavy industry, it aims to durably improve safety, health and the environment among contractor companies — those working on the sites of client organisations (chemicals, petrochemicals, energy, heavy industry). Its current reference document is the 2024 version of the manual. The process is specific: after joining, the company deploys its management system then triggers, within 9 to 18 months, an audit carried out by an approved audit firm; a steering committee — where client organisations and companies notably sit — then decides on certification, granted for one or three years depending on the maturity observed.

That is where the philosophies differ: ISO 45001 is a requirements standard audited by an accredited third party, with universal reach; MASE is an improvement scheme steered by a French industrial community, where client organisations themselves take part in governance.

What the two schemes share

On the ground, the overlaps are massive — good news for anyone considering holding both:

• a health and safety policy owned by top management, with objectives and indicators;
• risk assessment as the foundation (in France, anchored in the DUERP, the single occupational-risk assessment document — see our article on ISO 45001 and the DUERP);
• staff involvement: toolbox talks, field reporting, analysis of accidents and near misses;
• the continual improvement loop: audits, action plans, reviews.

This common core is no surprise: research has long shown that these ingredients — management commitment, staff participation, a lessons-learned loop — are what produce results. A study by Fernández-Muñiz and co-authors published in 2009 in Safety Science, conducted on Spanish companies, evidenced a positive relationship between the safety management system and the company’s overall performance, safety included (see the study). The scheme is a vehicle; it is the lived system that protects. The MASE association itself reports markedly lower accident rates among companies applying its approach.

What really sets them apart

Criterion	ISO 45001	MASE
Nature	Certifiable international standard	French association scheme (manual version 2024)
Recognition	Worldwide, all sectors	Very strong with French industrial client organisations
Certifier	Accredited third-party body	Approved audit firm + steering-committee decision
Certificate duration	3-year cycle, annual surveillance	1 or 3 years depending on results
Field	Occupational health and safety	Safety, health and environment
Integration	Native with ISO 9001 / ISO 14001 (common structure)	Own approach, compatible in practice

Two practical differences follow from this table. First, pace: with a MASE certificate granted for one year when maturity is judged insufficient, the company faces a full audit again quickly — demanding, but formative; the ISO cycle, for its part, smooths the effort with annual surveillance audits lighter than the initial one. Second, governance: in the MASE scheme, the decision belongs to a committee where client organisations themselves sit, which explains the pass’s authority on industrial sites; in the ISO world, it belongs to an accredited certification body, which grounds the certificate’s international recognition.

The deciding criterion is almost always your client portfolio. If your clients are the large French industrial sites — chemicals, refining, energy — MASE is frequently the expected entry ticket to work on their premises. If you answer international tenders, work for foreign groups or target an integrated QSE management system, ISO 45001 is the obvious choice. Many industrial-services companies end up holding both, with a single internal system.

Three profiles, three answers

• Contractor working on French chemical or oil sites: MASE first — it is what your clients ask for — while building the system so you can target ISO 45001 later without redoing everything.
• Mid-sized manufacturer with French and export clients: ISO 45001, possibly integrated with ISO 9001/ISO 14001; MASE as a complement if a key client organisation requires it.
• Company already MASE-certified whose international client demands “the ISO standard”: capitalise — your system already covers most of the substance; the gap mostly concerns formalisation along the standard’s clauses and the accredited certification process. The budget to plan for shrinks accordingly.

In every case, the golden rule of holding both is to build one single system: one risk assessment, one action plan, one field animation — and two reporting exercises depending on the scheme being audited. Companies that build two parallel systems pay for the animation twice and harvest inconsistency at both audits.

Take action

To frame your decision, consult both full pages: the ISO 45001 certification and the MASE certification — status, steps, frequently asked questions and a free ebook to structure whichever path you choose.