ILO C155 Explained: 4 Duties for Safer Workplaces

ILO C155 is more than an international declaration about safe work. The Occupational Safety and Health Convention, 1981 (No. 155), adopted by the International Labour Organization on June 22, 1981, connects national policy with what employers, workers, inspectors, and managers must make real at the workplace.

That distinction matters because a standard can exist on paper while the job still depends on improvisation. This explainer translates four duties in ILO C155 into decisions that an EHS manager or operations leader can verify, without treating ratification as proof that controls work in the field.

What is ILO C155?

ILO C155 is the International Labour Organization's Occupational Safety and Health Convention, 1981 (No. 155). It establishes a structure for a coherent national policy on occupational safety, health, and the working environment, while also addressing action required at the enterprise level.

The convention matters to workplace leaders because prevention is not reduced to training or personal caution. It includes the conditions in which work is designed, supervised, inspected, and improved, which makes the document useful as a governance lens even when a company is working under another management standard.

Duty 1: Build a coherent prevention policy

ILO C155 places prevention inside a policy system rather than leaving each site to create isolated rules. A workplace should therefore be able to explain which hazards matter, who owns the controls, how workers participate, and how the organization checks whether its policy changes exposure.

The practical test is not whether the policy contains the right vocabulary. It is whether a shift supervisor can connect a high-risk task to a control owner, an escalation route, and a review date. If those links are missing, the policy is descriptive rather than operational.

Duty 2: Keep the working environment under control

The convention treats the working environment as part of prevention, which means leaders must look beyond individual behavior. Equipment condition, chemical information, workload, access, maintenance, emergency arrangements, and the sequence of work can all change the risk presented by the same task.

Use the hierarchy of controls to test whether the organization is trying to reduce exposure at its source before depending on administrative reminders or PPE. A signed procedure does not prove that the work environment is controlled, because the actual barrier may be absent, bypassed, or impossible to use during the shift.

Duty 3: Give workers a meaningful safety voice

Worker participation is not a ceremonial consultation. It becomes meaningful when employees can identify changed conditions, challenge an unsafe plan, and receive a response that shows what happened to their concern.

A supervisor can test this duty during a pre-job discussion by asking what is different from the last job, which control is hardest to maintain, and what would make the team stop. The answers should influence the plan. Otherwise, participation is being collected without changing the decision.

Duty 4: Make inspection and correction credible

ILO C155 also points to the need for an adequate and appropriate system of inspection. At enterprise level, that principle becomes a question about evidence. Who verifies the control, how are findings prioritized, and what happens when the same weakness returns?

Leaders who already compare management systems can read this duty alongside ISO 45001, ANSI Z10, and ILO-OSH. The useful comparison is not which label looks strongest. It is which system makes ownership, verification, worker involvement, and corrective action visible in daily work.

How is ILO C155 different from ISO 45001?

ILO C155 is an international labour convention that sets principles for national policy and workplace prevention. ISO 45001 is a voluntary management-system standard that organizations use to structure and audit an occupational health and safety system.

They can complement each other, although they answer different questions. ILO C155 asks whether the policy and protection structure exists at the national and enterprise levels. ISO 45001 asks how an organization has arranged its system, processes, responsibilities, and continual improvement.

When should an EHS leader use ILO C155?

Use ILO C155 when a leadership team needs to test whether safety governance reaches the work itself, especially during a policy review, a multi-country program, a management-system comparison, or a discussion about worker participation and inspection.

It is also useful when an organization is mistaking certification for control. Pair the convention with a field review, a clear control owner, and evidence from the worksite. Andreza Araujo's Safety Culture: From Theory to Practice reinforces this practical distinction because culture is visible in repeated decisions, not in the existence of a document.

For the measurement side, compare the governance question with four types of safety indicators, then ask whether the chosen measures show prevention work or only the record of harm after it occurs.

What should a workplace verify first?

Start with one high-risk activity and trace the four duties through it. Identify the governing policy, inspect the working conditions, ask workers where the plan is fragile, and verify whether findings lead to timely correction.

That small review is more useful than a broad declaration of alignment because it shows where the system holds and where the work still relies on luck. ILO C155 becomes valuable when it changes what leaders inspect, who they involve, and what they refuse to leave unresolved.