Report of Market Access Ombudsman Council (May 13, 1994)

4-(1) International Harmonization of Fireproof Property Test for Steel Structures

1. Complainant: Embassy of the United States

2. Ministry concerned: Ministry of Construction

3. Complaint:

Testing for fireproof property, to determine resistance to heat in the event of fire, is carried out on the posts, beams, walls, floors and other principal structural elements of buildings. Testing is done mainly by a heating test, which involves heating samples from the main structural elements in a furnace heated at a specified temperature for a set time and measuring the temperature of the steel, to test the insulating capacity of fireproof coating materials.

The heating test carried out in Japan is based on Construction Ministry Notification No.2999 of 1969.

First, this Notification specifies the allowable temperature range of the steel (in the case of posts and beams, an average steel temperature of 350 °.C or less), but this is lower compared to various foreign standards.

Secondly, the temperature of the steel is determined by measuring the maximum temperature reached, including a rise in temperature after heating is completed, while in other countries the temperature of the steel when heating is completed is taken as the maximum temperature.

Thirdly, unlike other countries, actual temperature measurement, in the case of beams, is done by averaging the temperatures of the points measured by each three areas of the steel (upper flange, web, lower flange), to determine whether the temperature of each portion remains within the allowable range.

Accordingly, this means that in Japan, fireproof coating materials mentioned in this complaint must be at least 1.5 times and occasionally 3 times thicker compared to other countries.

The complainant holds that with regard to the three points mentioned above, Japanese standards and measurement methods should be harmonized with those of other countries, and that Japan should allow the use of materials which have been approved abroad.

4. Results of deliberation:

The ISO is currently coordinating for the establishment of international standards for fireproof property test. In response to the ISO's work in this area, the ministry concerned is currently studying specific policies relating to harmonizing fireproof property testing methods internationally, under "Development of Technology for Rational Testing and Evaluation System for Fire Safety Performance of Building" (FY1993-97), a General Technology Development Project. Once a final international standard is formulated, harmonization should be carried out as soon as possible, regardless of whether the project is still ongoing. And prior to this, testing methods should be harmonized with those of other countries as much as possible, based on the directions of ISO harmonization in mind and barring any safety risks.

Specifically, regarding the first point raised (maximum temperature), because there is a corresponding decrease in the strength of steel when temperature rises during a fire, with the steel becoming unable to bear a load once a certain temperature is reached, the issue is to determine the maximum allowable temperature to obtain the needed standard of strength in accordance with load limit. This needs comprehensive study, from the viewpoint of international harmonization, after a thorough investigation of the relation between allowable maximum temperature and load limit in other countries. Regarding the second and third points (temperature measurement methods), this is basically a matter of how the heating test is practically carried out, and after investigating the reasons for this and the methods used by the ISO and foreign countries, the necessary international harmonization should be implemented soon.

The ministry concerned, on receipt of this complaint, insists that the first point must be examined very carefully, since steel reaching a certain temperature becomes unable to bear a load, leading to building collapse. The ministry will aim at determining the direction of study by the end of June 1994. Regarding the second and third points, the ministry will aim at making a draft improvement plan for the testing methods by the end of August 1994, after confirming safety by necessary experiments in the above-mentioned development of technology. These issues should be logically resolved in this way.

From the viewpoint of harmonizing building standards and certification system with international standards, the ministry concerned supports the introduction of a mutual recognition system and is discussing the matter with foreign related authorities. Including the system mentioned in this complaint, performance evaluation according to foreign certification bodies should be accepted soon, based on results of discussions with foreign counterparts.

Government decision (June 24, 1994)

4-(1) Internatlona1 harmonization of fireproof property test for steel structures

The following measures will be taken to promote international harmonization.

(1) A technical development project will be promoted to internationally harmonize fireproof property testing methods soon after changes in international standards are mode by the ISO.

Fireproof property test is very important in ensuring the safety of stee1 structures, and the above-mentioned project wi11 study directions for international harmonization of testing methods by the end of June 1994.

Regarding part of the testing methods mentioned in this complaint, the necessary experiments will be carried out to check safety and a draft amendment may be prepared after this by the end of August.

(2) We will promote the introduction of a mutual recognition system, including the matter mentioned in this complaint, in the field of building, through discussions with related overseas organizations.

Follow-up (June 5, 1995)

4-(1) International Harmonization of Fireproof Property Test for Steel Structures

(1) Based on the ISO's revision of testing methods, the General Technology Development Project - "Development of Technology for Rational Testing and Evaluation System for Fire Safety Performance of Buildings" will be continued, to harmonize fireproof property testing methods internationally. During studies of this matter, it was decided in June 1994 to introduce the load-bearing heating test, in addition to the heating test which has been carried out so far.

Additionally, based on results of the above Project, parts of the fireproof property testing method (method of measuring average temperatures of the steel, timing of measurement of maximum temperature of the steel) were harmonized with international practices in November 1994.

(2) To support the introduction of a mutual recognition system in the construction industry, including the system mentioned in this complaint, consultations are being carried out with the related foreign authorities. The mutual recognition system will be introduced promptly after an agreement is reached with these authorities.

N.B.

Heating test:

testing to determine whether a maximum specified temperature is exceeded when steel coated with fireproof coating materials is heated in a furnace at a specified temperature for a set time.

Load-bearing heating test:

testing to determine whether the degree of distortion, etc. exceeds specific limits when steel coated with fireproof coating materials is heated in a load-bearing state in a furnace at a specified temperature for a set time.