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Current Trends in Chemical Substance Management
-- MSDS and the Dioxin Problem --

Chemical Substance Investigation Division
Industrial Safety and Health Department
Ministry of Labour

This paper was printed in "SANGYO-TO-HOKEN(industry and health) Vol.52" published by Shigematsu works co.,ltd. in Japanese. JICOSH was allowed by courtesy of Shigematsu works co.,ltd. to use this paper on its web. (translated by JICOSH)


(1) Introduction

Material safety data sheets (MSDS) are documents that list chemical substance names, components, chemical properties, hazards, and cautions on storing and handling. MSDS are issued to the receivers of chemical substances by people who transfer and supply such substances. This information ensures that employers, employees, and other related parties that handle chemical substances will be familiar with the associated hazards. (Refer to the example in Reference 1.)

Based on the purport of the Chemicals Convention (No. 170) that the International Labour Office (ILO) adopted in 1990 along with its accompanying Recommendation No. 177, the Ministry of Labour officially released in 1992 its Guidelines Concerning Indication of Hazards of Chemical Substances as a Ministry of Labour Bulletin providing instruction on the creation and issuing of MSDS.

The Ministry of International Trade and Industry (MITI) and the Ministry of Health and Welfare also provide instruction on the creation and issuing of MSDS, but they do so from different perspectives than that of the Ministry of Labour.

(2) Industrial Safety and Health Law

The Industrial Safety and Health Law has been revised, and matters concerning MSDS have been prescribed anew. The revision was an attempt to further complete chemical substance management measures in addition to past policies. The reason for the revision is that industrial accidents are still occurring in large numbers, and in order to prevent them, it is critical to reliably communicate information including chemical substance hazards in the workplace, and then based on this information, to establish countermeasures for appropriately preventing health problems in the workplace.

The revision mainly dealt with legislating that those who transfer and supply chemical substances that may potentially threaten employee health must issue MSDS to those who receive such chemicals. It also prescribed that the Minister of Labour shall publish guidelines concerning measures that employers must devise in order to prevent threats to employee health from chemical substances and other harmful materials, and that MSDS must be made widely available to employees who handle chemical substances by always having them posted in easily visible locations in the workplace.

Concerning the specific scope of chemical substances and other materials for which MSDS must be issued, items not covered by the manufacturing approval in paragraph 1, provision 56 of the Industrial Safety and Health Law are to be stipulated in a separate government ordinance. Future plans call for selecting chemical substances from among those that are subject to the recommendations of the Japanese Association of Industrial Health and the American Conference of Governmental Industrial Hygienists, Inc. (ACGIH). Note that the enforcement of the law revision is scheduled to begin on April 1, 2000.


2. The Dioxin Problem

(1) Introduction

Dioxin is a general term for the 210 isomers of polychlorinated dibenzodioxin (Figure 1) and polychlorinated dibenzofuran (Figure 2). Dioxins differ from the chemical substances normally manufactured and used in the chemical industry in that they are not created intentionally. Rather, they are generated as by-products when other substances are combined or when waste material is incinerated.

In Japan, mass media reports on the detection of dioxins in the ash and grounds around waste incineration facilities have triggered fears of environmental pollution and health risks associated with such chemicals. In light of such fears, the Ministry of Labour is also studying and researching dioxins at waste incineration facilities and pursuing countermeasures that prevent employee exposure.

The government recognizes that the dioxin problem is an issue that must be dealt with more forcefully through Cabinet meetings for the purpose of protecting the people  health and preserving the environment for the future. Based on this recognition, the government initiated the Extraordinary Cabinet Meeting on Dioxin Countermeasures, and on March 30 of this year, it reached a decision on the Basic Policy on Promoting Dioxin Countermeasures. In this basic policy, the government extols the promotion of measures such as those that reconsider the tolerable daily intake (TDI), along with those that promote measures for reducing the dioxin discharge, improve the inspection system concerning dioxins, and attempt to grasp the actual effects on health and the environment. To support the government, the Ministry of Labour has indicated that it will promote measures for setting up an industrial health management system, as well as measuring working environments, improving working environments, and promoting utilization of the appropriate protective equipment. It also indicated that it will attempt to grasp the health conditions of employees and the actual state of working environments.




 Figure 1: Polychlorinated Dibenzodioxin

 Figure 2: Polychlorinated Dibenzofuran

(2) Health Hazards of Dioxin

There have been reports on dioxin toxicity to humans that have acknowledged the occurrence of chloracne in groups exposed to high concentrations as a result of accidents at agricultural chemical manufacturing plants in Italy and Germany. Other reports have acknowledged through long-term epidemiological studies that frequent increases in cancer occurred in groups exposed to extremely high concentration when compared against groups that were not exposed. Furthermore, dioxin  effects as a substance that disturbs endocrines have been in the spotlight in recent years, but there are many unknown details regarding whether there are any direct effects on human health, and if there are, to what degree. At the present time, only 2, 3, 7, 8-tetrachlorodibenzo-p-dioxins (2, 3, 7, 8-TCDD) have been evaluated by the International Agency for Research on Cancer (IARC) as substances that cause human cancer.

Currently, the World Health Organization (WHO) is advocating a change in the tolerable daily intake (TDI) from the present 10 pg per 1 kg of bodyweight to 1 to 4 pg. As a result, the Ministry of Health and Welfare and the Environment Agency are considering revisions to the TDI in Japan.

(3) Investigative Research at the Ministry of Labour

In 1997, the Ministry of Labour established its Investigative Research Committee on Preventing Health Problems Due to Chemical Substances in the Waste Processing Business through which it is conducting investigative research on dioxins at waste incineration facilitates. Also in 1997, the Ministry measured the dioxin concentrations in working environments, incineration ash, and airborne ash at a general waste incineration facility and at an industrial waste incineration facility. This data was used for the Ministry  Research on Dioxins in Working Environments.

In 1998, the Ministry of Health and Welfare released a report stating that high concentrations of dioxins were detected in the soil after investigating the Toyono-gun Beautification Center. As a result, the Ministry of Labour began emergency studies of the facts behind dioxin exposure and the health status of employees engaged in work at that facility and commissioned the Japan Industrial Safety and Health Association to conduct investigative research.

The Japan Industrial Safety and Health Association conducted investigations through the Investigative Research Committee for the Toyono-gun Beautification Center Dioxin Problem that it had established. This resulted in reports stating that although dioxin concentrations in the blood of employees were higher than those of surrounding residents, no clear relationship was found between dioxin concentrations in the blood and health effects reported by employees and blood test results. The reports also stated that, based on the results of document searches, there was no conclusive evidence that the dioxin concentrations in the blood observed at this time clearly had an effect on employee health.

However, the Ministry of Labour is currently in the process of accumulating new information about the effects of dioxins on humans, and based on this, is planning to continue studies on Toyono-gun Beautification Center employees who had high concentrations of dioxins in their blood and to conduct future studies on other waste incineration facilities.

(4) Exposure Countermeasures at Waste Incineration Facilities

Based on the circumstances covered so far, in July 1998, the Ministry of Labour set forth its Dioxin Countermeasures at Waste Incineration Facilities (Notification No. 18 dated July 21, 1998 from the Safety and Health Department) as a means of preventing employee health problems caused by dioxins. Based on this Notification, the Ministry of Labour is now providing instructions on implementation of countermeasures such as working environment measurements, control measures for ash release, and the use of protective equipment for respiration. Based on the working environment measurements, this notification established 2.5 pg TEQ/m³ as the concentration to which dioxins must be controlled, and it is seeking to carry out measurements according to the B measurements of the working environment measurement standards as well as make evaluations of working environments according to working environment evaluation standards.

Furthermore, in April 1999, the Ministry issued Thoroughly Implementing Dioxin Countermeasures at Waste Incineration Facilities (Notification No. 231 dated April 7, 1999 from the Safety and Health Department), notifying the Labour Standard Bureau Chiefs of all prefectures that they should make requests of waste incineration facility operators and related regional governments. This notification seeks to have related operators set up countermeasures to prevent employee exposure to dioxins at waste incineration facilities as shown in Reference 2.

Basically, improving incinerators so that they produce less dioxin is crucial to preventing employee exposure. However, since exposure can also be prevented by industrial health controls such as the use of effective protective equipment for respiration, we would like to request that related parties thoroughly implement such controls as immediate measures.

Figure 1: Example of Working Environment Evaluation Results

Figure 2: Example of Protective Equipment for Respiration (Dust Respirator)



Primary control zone: Workplace where measured value is less than 2.5 pg TEQ/m³
Secondary control zone: Workplace where measured value between 2.5 and 3.7 pg TEQ/m³
Tertiary control zone: Workplace where measured value exceeds 3.7 pg TEQ/m³ 

Figure 3: Example of Air Mask and Respirator



Air Mask and Work Clothes


Note: Effective protective equipment for respiration requires that equipment performance correspond to the dioxin concentration verified by the results of working environment measurements.

Additional Information

  1. Dioxin is a general term for the 210 isomers of polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF). 

  2. The unit l pg (picogram) refers to 1/1-trillionth of a gram. 

  3. TEQ represents the conversion of the toxicity of 210 kinds of dioxin into the toxicity of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxins (2, 3, 7, 8-TCDD), which have the strongest toxicity. 

  4. The measurement and evaluation of dioxins in working environments should be carried out according to work environment measurement standards and work environment evaluation standards in order to prevent employee health problems. In light of this, it would be best that such measurements and evaluations be carried out by a work environment measurement organization that has been registered under the Working Environment Assessment Law. Please contact the Japan Working Environment Measurement Association (tel. 03-3456-0443) regarding the sampling method and other information. 

  5. Countermeasures against dioxins at waste incineration facilities (Notification No. 18 dated July 21, 1998 from the Safety and Health Department)