What Is Japan’s PRTR Law? Why Companies Need to Track Where Chemicals Go

JAPAN CHEMICAL REGULATION

Managing chemicals requires more than knowing whether a substance is hazardous.

Companies also need to understand who handles a chemical, how much is handled, how much is released into the air, water or other parts of the environment, how much leaves a facility as waste or through other transfer routes, and what information must be communicated to the next company handling that chemical.

To make these chemical flows visible across society, Japan enacted the Chemical Management Promotion Law in 1999.

Its formal English name is the Act on the Assessment of Releases of Specified Chemical Substances in the Environment and the Promotion of Management Improvement.

At the heart of the law are two systems: PRTR and SDS.

As of 2026, the law covers 515 Class I Designated Chemical Substances and 134 Class II Designated Chemical Substances. But with other Japanese chemical laws already in place, including the Chemical Substances Control Law and the Industrial Safety and Health Act, why is the PRTR Law necessary?

BASIC CONCEPT

1. What Is the PRTR Law? — It Is Not a Law That Simply “Bans” Chemicals

The name of the PRTR Law can sometimes create the impression that it is legislation designed to prohibit specific chemicals.

Its basic concept, however, is different.

The law is intended to promote improvements in the voluntary management of hazardous chemical substances by businesses and to prevent environmental problems before they occur.

Two major systems support this objective.

BACKGROUND

2. Why Was the PRTR System Needed?

Various laws governing chemical management existed long before the introduction of PRTR.

They addressed specific issues such as industrial wastewater, emissions to air, poisonous and deleterious substances, and worker safety.

However, there are practical limits to a system in which government authorities establish individual emission standards and directly control every one of the many chemical substances used throughout society.

This became an important principle.

Against the background of international initiatives including Agenda 21, adopted at the 1992 United Nations Conference on Environment and Development—the Earth Summit—the concept of identifying and publicly disclosing chemical releases spread internationally through PRTR systems.

Japan enacted the PRTR Law in 1999, creating a framework under which businesses themselves identify releases and transfers, while the government compiles and publishes the data so that chemical management can be improved across society.

PRTR

3. Understanding PRTR — The Difference Between “Releases” and “Transfers”

One of the most important concepts in understanding PRTR is the distinction between a release and a transfer.

For example, suppose a company sends waste liquid containing a designated chemical substance to an external waste treatment company.

The chemical has not been discharged directly from the factory into a river. But it has not simply disappeared from the factory either.

PRTR distinguishes between chemicals that are released into the environment and chemicals that are transferred elsewhere.

This is why PRTR is a Pollutant Release and Transfer Register, rather than merely a reporting system for environmental emissions.

SUBSTANCES

4. Which Chemical Substances Are Covered by PRTR?

As of 2026, the core substances covered by Japan’s PRTR system are the 515 Class I Designated Chemical Substances.

Class I Designated Chemical Substances are designated based on factors including hazards to human health or ecosystems and whether they are widely present in the environment or may become widely present in the future.

Among them, Specific Class I Designated Chemical Substances include substances recognized as presenting particularly significant hazards, including certain carcinogenic, mutagenic and reproductive toxic effects. Stricter reporting thresholds apply than for ordinary Class I substances.

REPORTING

5. Does Handling a Designated Substance Automatically Require PRTR Reporting?

No. Simply using even a small amount of a Class I Designated Chemical Substance does not automatically mean that a PRTR report must be filed.

As a general rule, reporting requirements apply in cases such as where the company operates in a covered business sector, has 21 or more regular employees across the business, and handles 1 tonne or more per year of a Class I Designated Chemical Substance at an individual facility.

For Specific Class I Designated Chemical Substances, the annual handling threshold is 0.5 tonnes or more. Certain facilities are also subject to requirements irrespective of the quantity handled.

The appropriate sequence is:

Substance → Concentration in the Product → Business Sector → Company Size → Annual Quantity Handled → Facility Requirements

MATERIAL BALANCE

6. “Quantity Used” Is Not the Same as “Quantity Released”

Another common misunderstanding under PRTR concerns the relationship between the annual quantity handled and the quantity released.

For example, even if a facility uses 10 tonnes of a chemical substance in a year, this does not mean that all 10 tonnes are released into the environment.

PRTR is not simply a system for reporting the amount of chemicals purchased.

It is also a framework for understanding the material balance of chemical substances.

TESTING & ANALYSIS

7. Does PRTR Reporting Require Everything to Be Measured?

The term PRTR may create the impression that every release must be determined through laboratory analysis.

That is not necessarily the case.

Release and transfer quantities can be calculated using various approaches, including mass balance calculations, actual measurement data, emission factors and physicochemical properties.

Analysis becomes important, however, where processes are complex, where concentrations in wastewater, exhaust gas or waste need to be determined, or where calculations alone cannot provide sufficient accuracy.

SDS

8. The Other Pillar — What Is an SDS?

The other major pillar of Japan’s PRTR Law is the SDS system.

SDS stands for Safety Data Sheet.

An SDS is a document used to systematically communicate information about a chemical product, including:

SDS REGULATIONS

9. Why Do the PRTR Law, Industrial Safety and Health Act and Poisonous and Deleterious Substances Control Act All Require SDSs?

In chemical management practice in Japan, three major laws are closely associated with SDS requirements: the PRTR Law, the Industrial Safety and Health Act, and the Poisonous and Deleterious Substances Control Act.

These are often collectively referred to in Japan as the “three SDS laws.”

In practice, a single SDS is commonly prepared to address requirements under multiple laws.

However, the substances covered and the scope of the obligations under these laws are not completely identical.

SDS SCOPE

10. Who Is Subject to SDS Requirements Under the PRTR Law?

PRTR reporting and SDS requirements differ in terms of which businesses are covered.

Under the SDS provisions of the PRTR Law, businesses that transfer or supply Class I or Class II Designated Chemical Substances, or covered products containing those substances at or above specified concentrations, to other businesses are subject to the relevant requirements.

Unlike the PRTR reporting system, the SDS system does not restrict applicability by business sector.

EXEMPTIONS

11. Is an SDS Required for Every Product?

No. Under the PRTR Law, certain products may fall outside the scope of the SDS requirements.

However, it is not appropriate to conclude simply that “a solid product is exempt.”

Products that may generate dust or other forms of exposure through processes such as cutting, grinding or melting may potentially fall within the scope of the requirements.

Whether an SDS is required therefore needs to be assessed not only from the substance name, but also from the concentration, product form, method of use or processing, and manner of distribution.

GHS & SDS

12. GHS and SDS Are Not the Same Thing

GHS stands for the Globally Harmonized System of Classification and Labelling of Chemicals.

It is an internationally harmonized framework for classifying chemical hazards and communicating that information through tools such as labels and SDSs.

Treating these three concepts as if they were the same makes the overall regulatory framework more difficult to understand.

CSCL VS PRTR LAW

13. How Is the Chemical Substances Control Law Different From the PRTR Law?

Japan’s Chemical Substances Control Law and PRTR Law are sometimes confused because of their similar Japanese names. Their roles, however, are quite different.

The two laws are not competing systems.

They support chemical management in Japan from different perspectives.

REGULATORY UPDATE

14. The List of Designated Substances Was Significantly Revised in 2023

The substances covered by the PRTR Law are not fixed permanently.

They are reviewed in light of factors such as new knowledge concerning hazards, detection in the environment, release volumes, and manufacturing and import volumes.

The relevant Cabinet Order was amended in 2021 and entered into force on April 1, 2023. For PRTR reporting, the revised list of designated substances began to apply to quantities identified for fiscal year 2023.

LATEST DATA

15. What the 2026 PRTR Data Shows

In February 2026, Japan’s Ministry of Economy, Trade and Industry and Ministry of the Environment published PRTR data for fiscal year 2024.

What matters is not simply that the combined figure exceeds 400,000 tonnes.

The significance of the PRTR system is that it enables society to continuously understand which substances are being released or transferred, in which regions, from which industries, and in what quantities.

MANAGEMENT

16. PRTR Is Not Simply a System for “Finding Violations”

The term PRTR may create the impression that the system is primarily about reporting emission quantities to government authorities.

But that alone does not capture its full purpose.

For example, if releases increase compared with the previous year, that can provide an opportunity to examine whether there were changes in production volume, manufacturing processes, recovery rates or raw materials.

PRTR is therefore both a reporting system for government authorities and a management tool that enables companies to understand the flow of chemicals within their own operations.

SUPPLY CHAIN

17. PRTR and SDS Are Connected Across the Supply Chain

At first glance, PRTR and SDS may appear to be separate systems.

In actual corporate practice, however, they are closely connected.

Starting with the SDS received from a raw-material supplier, a company identifies the types and concentrations of designated chemical substances.

It then organizes information on annual usage, manufacturing processes, products, air emissions, wastewater, waste and transfers to sewerage systems.

Where necessary, measurement and analysis are performed, and release and transfer quantities are calculated.

PRACTICAL CHECK

18. What Should Companies Check in Practice?

When considering compliance with the PRTR Law, companies do not need to begin by asking, “Do we need testing?”

The important point is that the presence of a designated substance does not automatically mean that testing should be performed.

Companies first need to determine what information must be identified, whether that information can be obtained from existing documentation or calculations, and which information, if any, can only be determined through measurement.

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