Chapter III.  Performance of Ventilation Systems

(Hood, etc., of Local Exhaust Ventilation Systems)

Article 14.  The hood of a local exhaust ventilation system (the ones stipulated by Chapter II; the same for this Chapter and item (2) of Article 19-2) shall comply with the following provisions.

(1)   Each hood shall be installed for each emission source of organic solvent vapour.

(2)   Hoods of outside mounting type shall be installed as close as possible to the emission source of organic solvent vapour.

(3)   Mode of Function: The hood shall be of a type and size suitable to suck in the vapour of the said organic solvents in connection with the work methods, the status of vapour emission, specific gravity of the vapour and the like.

2.  An employer shall make ducts of the local exhaust ventilation system as short as possible and minimize bending.

(Draft, etc.)

Article 15.  When an air cleaner is mounted on a local exhaust ventilation system, an employer shall install an exhaust fan at the location where cleaned air flows. Whereas, this provision is not applied when sucked vapour of organic solvents does not have a risk of explosion and does not corrode the fan.

2.  The employer shall install an air blower or exhaust fan of a general ventilation system (opening of a duct when the duct is used for the system) as close as possible to the emission source of organic solvent vapour in a general ventilation system (those which are provided for in Chapter II; the same for this Chapter and item (2) of Article 19-2).

(Exhaust Outlet)

Article 15-2.   The employer shall keep the exhaust outlet of local exhaust ventilation systems, push-pull type ventilation systems (here refers to push-pull type ventilation systems installed conforming to the provisions of Chapter II and same applies in this Chapter and Article 19-2 and item (6) of paragraph 1 of Article 33), general ventilation systems and exhaust pipes, etc., specified in sub-paragraph 1 of Article 12, directly open to the atmosphere.

2.  The employer shall keep the exhaust outlet of local exhaust ventilation systems, a push-pull type ventilation systems (restricted to those installed in indoor workshops) or the exhaust pipes, etc., specified in sub-paragraph 1 of Article 12, at a height of 1.5 m or more from the roof. However, this shall not apply where the concentration of the organic solvent discharged from the said outlet is lower than the concentration specified by the Minister of Labour.

(Performance of Local Exhaust Ventilation Systems)

Article 16.  The local exhaust ventilation system shall have a capacity to generate the controlled air velocity specified in the right column of the following table corresponding to the types specified in the left column of the same table.

Remarks  1)  Controlled air velocity in this table shall be defined as the one when all the hoods on the local exhaust ventilation system are set open.

                 2)  Controlled air velocity in this table shall be defined as the air velocity specified below corresponding to the types of the hood:

(a) In the case of the surrounding type hood, the minimum air velocity at the hood opening.

(b) In the case of the outside mounting type hood, the air velocity at the most distant operation point from the hood opening within the range of a hood which is to suck the vapour of organic solvents in the said area.

2.  Notwithstanding the provision of the preceding paragraph, when the local exhaust ventilation system falls under any one of the following categories, such a local exhaust ventilation system shall have a ventilating capacity of generating the controlled air velocity large enough to provide air flow rates equivalent to those of the general ventilation system which vary depending on the classification of the vapor-emitting organic solvents as are designated respectively in Article 17.

(1)   The local exhaust ventilation systems are provided conforming to the provision of paragraph 1 of Article 6.

(2)   The local exhaust ventilation systems are installed in the place where the installation of general ventilation system results in the exemption of the installation of the hermetically sealed container of the organic solvent vapor source or the local exhaust ventilation system because of the provision of paragraph 2 of Article 8, paragraph 1 of Article 9 or Article 11.

(Performance, etc., of Push-Pull Type Ventilation System)

Article 16-2.   The push-pull type ventilation system shall have the construction and exert the performance designated by the Minister of Labour.

(Performance of General Ventilation Systems)

Article 17.  A general ventilation system shall have the capacity for per minute ventilation volumes as computed based on the equations specified in the right column of the following table corresponding to the classification specified in the left column of the same table (when organic solvents of the different classifications are consumed simultaneously, the per minute ventilation volumes computed separately by respective classifications shall be added up).

Remarks:Q and W in this table stand for the following figures:

       Q:   Ventilation volume per minute (unit: m³)

      W:    Weight of organic solvents to be consumed in one working hour (unit: g)

2.  The weight of organic solvents to be consumed in one working hour stipulated in the preceding paragraph shall be as provided for in the following items:

(1)   Work specified in a) and b) of item (6), paragraph 1 of Article 1: Weight of organic solvents evaporated in one working hour.

(2)   Work specified in c) throughf), h), i) or k) of item (6), paragraph 1 of Article 1: Weight obtained by multiplying a figure separately provided by the Minister of Labour by the weight of organic solvents to be consumed in one working hour.

(3)   Work specified in g) or j) of item (6), paragraph1 of Article 1: Weight obtained by multiplying a figure separately provided by the Minister of Labour by the weight of organic solvents applied to or sticking to the materials to be dried or adhered, respectively, in one working hour.

3.  The provisions of the latter part of paragraph 2 of Article 2 shall be applied to the weight of organic solvents to be consumed in one working hour of the work stipulated in the preceding paragraph.

(Operation of Ventilation Systems)

Article 18.  Where a local exhaust ventilation system is installed, the employer shall operate said local exhaust ventilation system in accordance with the models specified in the left column of the table in paragraph 1 of Article 16 at a controlled air velocity equal to or above the controlled air velocity specified respectively in the right column of the same table when workers are engaged in organic solvents work.

2. Notwithstanding the provision of the preceding paragraph, where the said local exhaust ventilation system is covered by any of the provisions of items in paragraph 2 of Article 16, it may be operated at a controlled air velocity equal to or above the controlled air velocity stipulated in the same paragraph >.

3. Where a push-pull type ventilation system is installed, the employer shall operate the said push-pull type ventilation system so as to satisfy the conditions stipulated by the Minister of Labour when workers are engaged in organic solvents work.

4. Where a general ventilation system is installed, the employer shall operate the said general ventilation system in accordance with the classifications stipulated in the left column of the table in paragraph 1 of the preceding Article at a ventilation volume equal to or above the ventilation volume per minute stipulated respectively in the right column of the same table when workers are engaged in organic solvents work.

5. Where a local exhaust system, a push-pull type ventilation system or a general ventilation system is installed, the employer shall take the necessary measures to operate the said system effectively such as installing a baffle to prevent air currents that impede ventilation. 

(Special Measures for Local Exhaust Ventilation Systems)

       Article 18-2. Notwithstanding the provision of paragraph 1 of the preceding Article, where measurements of a workplace relating to the said local exhaust ventilation system under the provision of paragraph 2 of Article 28 and the provision of paragraph 5 of Article 65  of the Industrial Safety and Health Law (called the "Law" below) and an evaluation of the said measurements have been carried out during the said previous eighteen months and where the results of the said evaluation are consistently classified in the first-grade section, the employer may, after taking the following measures, operate the said local exhaust ventilation system at a controlled air velocity less than that stipulated in the right column of the table in paragraph 1 of Article 16 for the models described in the left column of the same table when taking measurements of organic solvent concentration in order to obtain the permission specified in paragraph 1 of the following Article.

1)    Appoint a person to check the following matters from among those with necessary competence to check the said matters and have them check the said matters in advance.

a)    That the controlled air velocity is stable when the said local exhaust ventilation system is operated at the relevant controlled air velocity

b)    That the hood of the said local exhaust ventilation system which is to extract organic solvent vapour is able to extract organic solvent vapour from the most distant operation point from the hood opening within the range of the said hood when the said local exhaust ventilation system is operated at the relevant controlled air velocity.

2)    Workers engaged in organic solvents work in the area of the said local exhaust ventilation system shall be required to use air-supplied respirators or masks to prevent organic solvent poisoning.

             2. When requiring workers to use the air-supplied respirators stipulated under the provision of sub-paragraph 2 of the preceding paragraph, the employer shall take measures to ensure that the said workers do not inhale toxic air.

           Article 18-3. Notwithstanding the provision of paragraph 1 of Article 18, where a local exhaust ventilation system is operated at a controlled air velocity less than that specified in the right column of the table in paragraph 1 of Article 16 for each of the model types specified in the left column of the same table under the provisions of the preceding Article and measurements are taken of organic solvent concentration (applies only to those carried out in normal workplace conditions under the provision of paragraph 2 of Article 65 of the Law and the provision of Article 3 of the Enforcement Order for the style='background:yellow;'>Work Environment Measurement Law (Ministry of Labour Ordinance No. 20 of 1975), the same applies in the following paragraph) in the workplace related to the said local exhaust ventilation system with the results evaluated in accordance with the provision of paragraph 1 of Article 28-2 producing a first-grade section, the said local exhaust ventilation system may be operated at the said controlled air velocity (called "Exceptional Controlled Air Velocity" below) with the permission of the Chief of the competent Labour Standards Inspection Office.

             2. An employer intending to obtain the permission covered in the preceding paragraph shall attach the following documents concerning the application for the local exhaust ventilation system to the Local Exhaust System Exceptional Operation Permit Application Form (Form 2-2) and submit it to the Chief of the competent Labour Standards Inspection Office.

1)    A sketch of the workplace

2)    A written record of the results of measurements taken in the said workplace during the eighteen months prior to the application under the provisions of paragraph 2 of Article 28 and paragraph 5 of Article 65 of the Law and the evaluation of the said results of measurements under the provision of paragraph 1 of Article 18-2 

3)    A written record of the results of measurements of the concentration of organic solvents in the said workplace with the said local exhaust ventilation system operated at the exceptional controlled air velocity and the evaluation of the results of measurement carried out in accordance with the provision of paragraph 1 of Article 28-2.

4)    A written record showing that the notification stipulated under the provision of the main text of paragraph 1 of Article 88 of the Law (including cases where paragraph 2 of the same Article applies) has been carried out

5)    A written record of the results of voluntary inspections stipulated in paragraph 2 of Article 20 carried out during the two years prior to the application

             3. When receiving a submission of an application provided for in the provisions of the preceding paragraph, the Chief of the competent Labour Standards Inspection Office shall notify in writing the said employer without delay when he/she has decided to grant or not grant the permit under paragraph 1.

             4.  An employer in receipt of a permit under paragraph 1 shall notify the Chief of the competent Labour Standards Inspection Office in writing without delay of the matters under each item of paragraph 3 of Article 28 and the matters under each item of paragraph 2 of Article 28-2 when measurements of the workplace to which the permit relates are carried out under the provision of paragraph 2 of Article 28 and evaluation of the results of the said measurements made under the provision of paragraph 1 of Article 28-2.

             5. An employer in receipt of a permit under paragraph 1 shall inform the Chief of the competent Labour Standards Inspection Office in writing without delay when there are any changes to the details recorded on the application form and documents under paragraph 2.

             6. Where the evaluation in paragraph 4 was not in the first-grade section and when it is deemed likely that the evaluation of the results of the measurements of a workplace relating to a permit under paragraph 1 carried out under paragraph 2 of Article 28 will not maintain the first-grade section under paragraph 1 of Article 28-2, the Chief of the competent Labour Standards Inspection Office shall cancel the said permit without delay.