Report of Review Panel Meetings on

Preventive Measures for Worker Exposure to
Chemical Substances Posing Unknown Risks to
Human Health(Nanomaterials)

November 20081

Table of Contents
Part 1

Foreword

Part 2

Applications, Production Volume, and Nature of Nanomaterials

Part 3

Perspective and Scope for Considering Exposure Preventive Measures

Part 4

Results of Considerations Associated with Exposure Preventive Measures

Part 5Afterword

2

Part 1 Foreword
1 Background“Nano” in “nanomaterials” denotes one-billionth (10-9) and “one nanometer” isequivalent to one-thousandth of a micrometer. A nanomaterial is a material with nano-scaledimensions. It is well known that nanomaterials possess unique chemical and physicalproperties when the compositional structure size decreases. This raises expectations of
new materials having more excellent properties than existing materials. As a result, many
international researches and developments on nanomaterials have been actively
undertaken. Engineered nanomaterials have been produced as carbon black, silica,
titanium oxides, and zinc oxides, and so on. The materials already have been applied forvarious purposes, for example, tires, silicone rubbers, cosmetics, and pharmaceuticals,
and so on. In recent years, research and development, mainly on carbon nanotubes, havebeen actively pursued; therefore, in the future, more new nanomaterials are expected to befurther developed and used for a wide range of applications.
Meanwhile, although many studies on the health effects of nanomaterials have been
conducted around the world, the necessary degree of knowledge has not been gatheredyet. Recently, some academic papers reported that nanomaterial caused adverse effects tomice under certain conditions, but there has been no report that those nanomaterials may
cause adverse effects to human health.
As the production and application of nanomaterials expands, workers engaged in their
manufacturing and handling are expected to increase rapidly in the near future. From theview of proactively preventing the health impairment of such workers, the Ministry of Health,Labour and Welfare(MHLW) has issued interim preventive measures against exposure tonanomaterials in workplaces on February 7th of 2008, as a “Notification on Present
Preventive Measures for the Prevention of Exposure at Workplaces Manufacturing and
Handling

Nanomaterials”

based

on

an

internationally,

well-known

basic

concept, ”precautionary approach”, and the MHLW is promoting extensive dissemination of
the Notification.
In order to increase the efficiency of countermeasures for the control of nanomaterials,
a more specific management approach based on the status of workplaces should bepresented and also, the current situation of and future challenges on exposure preventive
measures need to be considered. This time, review panel meetings entitled ” Review Panelon Preventive Measures for Worker Exposure to Chemical Substances Posing Unknown
Risks” (Panel Chair: Shoji Fukushima, Director of Japan Bioassay Research Center, Japan3

Industrial Safety and Health Association (JISHA)) were held with participation of academic
experts where they discussed preventive measures against exposure to nanomaterials. As
a result of these meetings, this report was released.

4

2 Attendee List of “Review Panel on Preventive Measures for Worker Exposure to
Chemical Substances Posing Unknown Risks” (dispensed with Mr./Mrs.)
Kazuyuki Omae

Prof. of Department of Preventive Medicine and Public Health,
School of Medicine, Keio University

Yasutaka Ogawa

Manager of Department of Research Planning and Coordination,
Japan National Institute of Occupational Safety and HealthJNIOSH

Masayoshi Karasawa

Licensed Occupational Health Consultant

Yoshihito Konishi

Managerof

Investigation&

Research

Department,

Japan

Association of Working Environment (JAWE)
Fumiaki Shono

General Manager of Chemical Management Department/Vice
Secretary-General of REACH Task Force, Japanese Chemical
Industry Association (JCIA)

Shigeru Tanaka

Prof. of School of Human Life Sciences, Department of Food &Nutrition of the Faculty of Human Life, Jumonji University

Toshio Nagoya

Prof. of Waseda University Faculty of Science and Engineering○ Shoji Fukushima

Director of Japan Bioassay Research Center, JISHA(Special Attendees Related to the Field of Nanotechnology)
Jun Ogawa

Member of Standardization & Social Implications Committee,
Nanotechnology Business Creation Initiative (NBCI)

Masashi Gamo

Head of Risk Management Strategy Team, Research Center for
Chemical Risk Management, Advanced Institute of Science andTechnology (AIST)

Jun Kanno

Head of Division of Toxicology, Biological Safety Research Center,
National Institute of Health Sciences (NIHS)

Shigeki Koda

Senior Research Fellow of Hazard Evaluation and Epidemiology
Research Group, JNIOSH

Ayako Takata

Lecturer of Department of Preventive Medicine, St. Marianna
University School of Medicine

Toshihiko Myojo

Associate Prof. of Department of Environmental Health Engineering,
University of Occupational and Environmental Health, Institute ofIndustrial Ecological Sciences○：Panel Chair
5* The above affiliation and titles of attendees were provided at the time when the firstreview panel meeting was held.
3 Chronology of Review Panel Meetings
The 1st Meeting (March 3rd, 2008 (Mon))・ Holding of Review Panel Meetings
・ Nanomaterials
・ Past Efforts Taken by the MHLW, etc.
・ Future Plan for the Subsequent Review Panel Meetings
The 2nd Meeting (April 4th, 2008 (Fri))・ Scope of Nanomaterials
・ Status on the Development of Nanomaterials
・ Development of Measurement Technology for Nanomaterials
The 3rd Meeting (May 2nd, 2008 (Fri))・ Health Effects Caused by Nanomaterials
The 4th Meeting (May 30th, 2008 (Fri))・

Current Status and Countermeasures of Occupational Hygiene in Handling
Nanomaterials; Results of a Questionnaire Survey to Related Enterprises

・ Response to Notifications
・ Future Agenda
The 5th Meeting (July 9th, 2008 (Wed))
・ Preventive Measures for Avoiding Exposure to Nanomaterials
The 6th Meeting (July 30th, 2008 (Wed))
・ Preventive Measures for Avoiding Exposure to Nanomaterials
The 7th Meeting (August 28th, 2008 (Thur))・ Preventive Measures for Avoiding Exposure to Nanomaterials
The 8th Meeting (Oct. 1st, 2008 (Wed))
6

・ (Proposed) Reports
The 9th Meeting (Oct. 31st, 2008 (Fri))・ (Proposed) Reports
Part2

Applications, Production Volume and Nature of Nanomaterials

1 Applications and Production Volume of Nanomaterials in Japan
According to the MHLW-sponsored research conducted in 2007, applications andproduction volume of nanomaterials are as shown in Table 1 and Table 2, respectively.
This research was performed among 21 types of nanomaterials, some of which are
already in practical use, others of which are at an advanced development stage.
For particle diameters, carbon-based nanomaterials are the smallest, diameter offullerene particles was 1nm or smaller, and that of single-walled carbon nanotube(SWCNT) was roughly 1nm.
Theapplications

of

most

nanomaterials

includehome

appliancesandelectrical/electronic products, cosmetics, or paint and inks. When looking at the results by
category, silica, silver, silver ion deposited onto inorganic microparticles (silica, alumina,etc), titanium oxides, nanoclay, and zinc oxides are used in various fields (See Table 1).
For production volumes (i.e., usage), carbon black, silica, titanium oxides, and zincoxides account for the major part of the total (See Table 2).
The usage status of major nanomaterials is summarized in the following paragraphs.
(1) Carbon BlackThe domestic usage in 2006 is 1 million tons. Carbon black is usually used by mixing
into rubbers or resins, and/or by adding to solvents. 80% of the total usage is used for tires,
15% is for other rubber products and 5% is used for coloring such as inks or paints.
Advantages in use include reinforcement of rubbers, enhancement in electrical conductivity
and colorability of rubbers/resins, and improvement of tinting strength as a pigment.
(2) Silica (crystalline and amorphous)
The domestic usage in 2006 is approximately 13,500 tons. Silica is used in silicone
rubber, FRP, and paints. Advantages in use include improvement in strength and theenhancement of insulation properties and water resistance.
(3) Titanium Oxide (rutile-type and anatase-type)7

Titanium oxide exists in different crystal structure, “rutile and anatase type”. The rutile
crystaline has larger production volume. The domestic usage in 2006 is approximately
1,250 tons. Titanium oxide is used in cosmetics, toners, and car paints. Advantages in use
include ultraviolet protection, charge adjustment, and photocatalytic action.
(4) Zinc Oxide
The domestic usage in 2006 is approximately 480 tons. Zinc oxide is mainly used forcosmetics. Advantages in use include ultraviolet protection over a wide range of
wavelength and enhancement in transparency.
(5) SWCNTThe domestic usage in 2006 is approximately 100 kilograms. Although SWCNT is usedby mixing with resins and/or ceramics, its useful application is currently being researchedand developed. Advantages in use include reduction in weight and assignment ofelectrical conductivity.
(6) Multi-walled Carbon Nanotube (MWCNT)The domestic usage in 2006 is approximately 60 tons. MWCNT is used forsemiconductor trays. Advantages in use include assignment of electrical conductivity,
improvement in strength, and electromagnetic shielding properties.
(7) Fullerene
The domestic usage in 2006 is approximately 2 tons. Fullerenes are widely used forsporting goods. Advantages in use include the enhancement of repulsion, reduction inweight, and improvement in strength.
(8) Dendrimer
Dendrimer is a dendritic macromolecule with a structure symmetrically branched out
from its center, which consists of the center portion (core) and the peripheral side chains(dendron). It has been elucidated that the core surrounded by dendrons resides in anenvironment isolated from the outside, which results in the unique luminescence behavior
and reactivities of dendrimers. Currently, Dendrimer is expected as a new functional
material as a new functional material.
The domestic usage in 2006 is approximately 50 tons for papermaking and several tons
for cosmetic use, showing that consumption for papermaking outweighs that for other8

purposes. One of the applications of dendrimers for papermaking is a paper coating agent.
Advantages in use include rheology (flow characteristics) control for papermaking andwater/oil repellency for cosmetics’ application.
(These data are sourced from Toray Research Center, Inc. (TRC)/Toray Corporate
Business Research, Inc. (TBR), and partially revised)

Fullerene
SWCNT
MWCNT
SilverSilver + Inorganic
Microparticles
Steel
Carbon Black
Titanium Oxide
Alumina
Cerium Oxide
Zinc Oxide
SilicaPolystyrene
Dendrimer
Nanoclay

U

{

U
U

{
U

{

{
{

{

U
{

{U

{
{
{
{
U
{
{
{
{U
{

{

Quantum Dot

{

{

{

{
{

{

Carbon Nanofiber
Pigment
Microparticles
Acrylic
Microparticles
Liposome
Platinum
Nanocolloid

{

U
{U
{
{U
{
{
{U
{
{U
{
U
{
{
U
{

Other
Paper-making

Paints & Inks

Home Appliances &Electrical/Electronic
Products

Household &Sporting Goods

Fiber

Cosmetics

Food & Packages

Pharmaceuticals,
etc.

Table 1. Nanomaterial’s Applications Classified by Type{U Catalyst
{
{
{U
U
{
{
{U
{

{U

{ Tires{{{{ Agrochemicals
U Propellers forWind Generators

{
{
{

U

{

{

{

{

U

Nickel{U

U{ Catalyst

U{ Reagents forLaboratories{

Note) Signs {, U, and {U in the above represents as follows:{：current application, U：potential application in the future, {U：predominant application
areas expected in the future

9

SWCNT：Single-walled Carbon Nanotube
MWCNT：Multi-walled Carbon Nanotube
Liposome：has a spherical shell structure composed of lipid bilayer membrane. Although
the size depends upon production methods and/or conditions, the diameter ranges
approximately from 20nm to 100nm. Liposome has a basic structure of bio membranes,
which triggers the research and development for its application to drug delivery system,
biosensors, etc.
Quantum dot：An virtual molecule obtained from the coupling of two “artificial atoms” thatare artificially formed through a semiconductor microprocessing technology. Quantum dots
are expected to be applied to quantum computers, which can provide ultrafast calculations.
Some study considers whether its fluorochrome can be used as a label in bodytissues/cells.
(The above information was provided by Toray Research Center, Inc. (TRC)/Toray
Corporate Business Research, Inc. (TBR), and partially revised)10Table 2. Annual Japanese Usage and Particle Diameters of Major Nanomaterials (Overall
Overhead View)
Usage

Carbon Black: 1 million tons

Silica : 13,500 tons

Titanium Oxide: 1,250 tons
1000
tons
Explanation of Arrows: Customized to a size of 100nm or smaller: Roughly adjusted in a range indicated by this arrow: Submicron particles may exist

500
tons

Zinc Oxide : 480 tons

100
tons
NWCNT: 60tons
Dendrimer: 50 tons

Fullerene: 2 tons
1
ton
SWCNT: 0.1 tons

Particle Diameter

11

(The above information was provided by Toray Research Center, Inc. (TRC)/Toray
Corporate Business Research, Inc. (TBR), and partially revised)
2 Nature of Nanomaterials(1) Properties of Nanomaterials
Many properties of materials (such as electric, optical, and/or magnetic properties)
depend on the electron states in the material. For nanomaterials, the reduction of thestructure size induces alterations in the state of their electrons, which creates unique
phenomenon that cannot be observed in ordinary macroscale materials.
Most nanomaterials have higher chemical reactivities due to their relatively large
surface area.

The specific surface area (surface area per unit mass) of particle becomeslarger by reducing the size of it; this means the surface where chemical reaction occurs
becomes larger.
In many cases, nanoscale particles have high strength because the size reduction of amaterial leads to the decrease defects in the material. For example, SWCNT isapproximately five to twenty times stronger than steel wires and has about a twenty times
higher elastic module than that of steel wires. For metal materials, it is known that thesmaller the diameter of the crystal particle, the higher the hardness of the material.
The electrical property of nanomaterials is as follows. When a voltage is applied tomacroscale matter, the electrical current is proportional to the voltage and changes
continuously. However, as the size of matter approaches the nanoscale range, electricalcurrent values become discrete.
The magnetic property is as follows. A ordinary-use magnet is composed of anassembly of small magnetic domains. However, when the magnet is scaled down tonanometer size, the nanomaterial, itself, corresponds to one magnetic domain and exhibits
very high retention.
The optical property is as follows. A material showing metallic luster can give off colors,
when the size of the material is decreased to nanoscale. These colors will vary dependingon the size of nanomaterials.
(2) Health effects of Nanomaterials
In vitro test results are reported that some nanomaterial show cytotoxic suppression
and or cytostatic properties.
Meanwhile, in vivo test results show that under specific conditions, exposure to some12

nanomaterial induces an inflammation response in the lungs, etc. of mice and rats. Also,
recent studies indicate that the instillation of MWCNT into the peritoneal cavity of mice andinto the scrotal cavity of rats induced peritoneal mesotheliomas. However, with regard to
inhalation through the respiratory tract, which is considered as main exposure route inworkplaces, long-term exposure tests with small laboratory animals have not yet been
conducted. Furthermore, there has been no report whether MWCNT may give rise to
adverse effects on human health.
As mentioned above, the use of nanomaterials, excluding some types, has been rapidly
growing; while many studies about health effects of nanomaterials have been moving
forward simultaneously. However, their mechanisms still remain to be fully elucidated.

13

Part3

Perspective and Scope for Considering Exposure Preventive Measures

1 Current Status of Legal Regulations and Safety Measures
Nanomaterials are present as nano sized particles or nano sized fibrous matter. They
usually have a powdery appearance. For some nanomaterials, such as carbon blacks
and/or titanium oxides, manufacturing and handling of them may correspond to “operations
in a dusty environment”. In that case, the employers have to enforce facilitical measures,
workingmanagement,

andoccupational

healthmanagement

based

on

the

Pneumoconiosis Law, the Industrial Safety and Health Law (ISHL), the Enforcement
Ordinance of the Pneumoconiosis Law, the Ordinance on Prevention of Hazards Due toDust, and other related regulations. These legislative regulations will be applied to the casenot because the matter corresponds to nanomaterials but because both the relevantmaterial and its manufacturing and handling correspond to the “operations in a dusty
environment” specified in the legislative regulations.
Additionally, a provision specified in Article 28-2 of the ISHL entitled, “Investigation, etc.
to be Carried Out by Employer” states that: “The employer shall endeavor to investigate thedanger or harm, etc. due to raw materials, gases, vapors, dust, etc. and to take necessary
measures for preventing dangers or health impairment to workers, in addition to taking themeasures provided for by the provisions pursuant to this Act or the orders based on the
results of the said investigations.” Therefore, it is essential that any employer who isengaged in, for example, manufacturing, handling, or importing/exporting nanomaterials
must conduct research on the dangers and harmful effects of nanomaterials based on theabove provision and take necessary measures based on the research results.
In recent years, the research and development of and the applications of nanomaterials
have been in progress. Therefore, it is expected that, from now on, the number of workers
who are engaged in manufacturing and handling nanomaterials will increase. Meanwhile,
although the actual exposure status and adverse health effects of nanomaterials on
humans are not still completely elucidated, experiments with small laboratory animals
suggest potential health effects of nanomaterials. Thus, from the view point of“precautionary approach”, the MHLW issued, as a notification from the Director General ofLabour Standards Bureau, LSB Notifications No. 0207003 and No. 0207004,
entitled ”Notification on Present Preventive Measures for the Prevention of Exposure at
Workplaces Manufacturing and Handling Nanomaterials” (hereinafter referred to as“Notification”) and has been urging employers of the relevant workplaces to implement
appropriate exposure preventive measures.
14

2 Scope of Considering
Although the above-mentioned Director’s Notification has been issued as an interim
measure from the MHLW, in order to increase the efficiency of countermeasures for thecontrol of nanomaterials, a more specific management approach should be presented andfurther, the current situation and future challenges on exposure preventive measures need
to be considered. Therefore, this review panel decided to consider the following subjects:(1) Scope of nanomaterials to be targeted for the preventive measures;(2) Interim exposure preventive measures associated with nanomaterials; and(3) Future occupational health and safety problems associated with nanomaterials.
3 Perspectives for Considering Preventive Measures(1) Because there are no exposure control values for nanomaterials such as allowable
concentration, it is impossible to adopt the conventional methodology of management
practices for nanomaterials that is performed based on the exposure level andconcentration of a substance. Therefore, for preventive measures, we have determined
to take a recently, worldwide well-known approach, so-called “precautionary
approach”1.
(2) In considering measures for nanomaterial exposure, we decided to seek the best
feasible solution by taking into consideration overseas trends, the latest scientificknowledge, the status of control practices taken in workplaces, and the progress of
relevant technology, etc.
(3) In general, nanomaterials exist in powder form under ordinary conditions and exhibit
particular electrical, chemical, and physical properties that arise from their size reduction to1

Precautionary Approach

The basic concept of the preventive approach is as specified in Principle 15 of Rio Declaration on
Environment and Development (The United Nations Conference on Environment and Development held in1992) stating “･･･, the precautionary approach shall be widely applied by States according to theircapabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shallnot be used as a reason for postponing cast-effective measures to prevent environmental degradation.”
In addition, the 2002 Johannesburg Summit agreed upon the goal of achieving sound chemicals
management based on an international commitment, “By 2020, chemicals should be used and producedin ways that lead to minimization of adverse effects on humans and the environment”. As a measure forachieving this commitment, SAICM (Strategic Approach to International Chemicals Management process),which was adopted in 2006, recommends the adoption of the precautionary approach.

15

the nano-scale range. Moreover, at present, the harmful effects of each nanomaterial still
remain unclear. Therefore, we decided to consider interim preventive measures against
exposure to nanomaterials, not based on each type of nanomaterials but on the wholegroup of nanomaterials.
Part 4

Results of Considerations Associated with Exposure Preventive Measures

1 Basic Points(1) Scope of Nanomaterials to be Targeted for Exposure Preventive Measures
In the Notification, targeted nanomaterials are defined as “solid state materials
manufactured using chemical elements and so on as a raw material”. The Notification limits
the target scope of nanomaterials exclusively to manmade materials. Other than
engineered nanomaterials, various nano-sized particles occur in nature. Currently, any
occupational health concerns do not arise from these nanoparticles; therefore, it can besaid that nano-size particles present in nature fall beyond the target range. Additionally,
although there still remains the possibility that nano-sized materials may occur
unexpectedly during ordinary processes such as a manufacturing process, at present, no
occupational health concerns arise from such nano-sized materials. Therefore, it can beagain said that they fall beyond the target range.
The Notification defines only the upper size limit of nanomaterials. In most of othercountries, the lower size limit is usually defined as 1nm, but unless the lower limit is defined,even an atom will be targeted. Therefore, it would be appropriate that the present definition
should be restated as follows: ”nano-objects2 with at least one of three dimensions ofapproximately 1nm － 100nm and a nano-structured material composed of suchnano-objects (including objects containing nano-scale structure and aggregate ofnano-objects)”
Additionally, in the Notification, the aggregation of nano-objects is also targeted forpreventive measures. Results of in vitro tests showed that aggregated nano-structured
materials cannot be easily separated; in other tests for fullerenes, it was reported that, once
they enter into the body, nano-structured materials are subjected to strong biologicaleffects, including effects by macrophages and biological redox effects, and are likely to be
separated. Even if the size of an aggregated nano-structured material is beyond 100nm
and if the size of nano-objects is less than 100nm, it is proper for the aggregated2

Descriptions are provided according to the definition of ISO/TC229 TS27687 Nanotechnologies－
Terminology and definitions for nano-objects－nanoparticles, nanofibre and nanoplate. Nano-objects
include three types: nanoparticles; nanofibre; and nanoplate. However, Japanese translation of theseterms remains tentative.

16

nano-structured material to be involved in the target range.
(2) Workers to be Targeted for Exposure Preventive Measures
The workers with the chance of exposure to nanomaterials are those who are engaged
in manufacturing or handling nanomaterials or formulations containing nanomaterials(including repairs and inspections of equipment or instruments as well as manufacturingand handling for scientific purposes, etc.) in a workplace and those who are engaged insupervising these operations in the same workplace. Therefore, here it is appropriate toredefine the definition as ”the scope of workers include those(including supervisors) who
are engaged in manufacturing or handling nanomaterials or formulations containing
nanomaterials in a workplace”.
In handling products in which nanomaterials are used, only when the nanomaterials areembedded in the products or otherwise, they exist in a stable state and cannot be expected
to break free, it may be considered that there is little chance of exposure to those
nanomaterials. However, for instance, when these products are disposed of, the possibility
cannot be denied that nanomaterials may be released from inside the product, causing
occupational exposure for workers who are engaged in the disposal operations. Therefore,
it is appropriate that the scope of workers should include not only workers who are
engaged in manufacturing and handling nanomaterials, but also workers who are engaged
in disposing of and recycling products containing nanomaterials.
(3) Exposure Routes of Nanomaterials
Possible exposure routes of nanomaterials can be considered as follows:aInhalation exposure through the respiratory tract such as lung, etc., which is the mostcommon exposure pathway of suspended particles in working environment;b

Entry into the body from nerve endings in the nasal cavity, which is another exposure

pathway by inhalation;c Entry into the body through skin contactdEntry into the body through the mucous membrane of the eyes; ande

Entry into the body by oral ingestion17

(4) Manufacturing and Handling Operations Associated with Nanomaterials and their
Chance of Exposure
Examples of manufacturing and handling operations associated with nanomaterials
include the following:
・ Production
・ Receiving
・ Weighing
・ Inputting into equipment（such as kneading with resins or inputting of raw materials）
・ Collecting from production/processing equipment, and translocation of containers (suchas translocation of intermediate products)
・ Cleaning and maintenance of equipment/containers・

Other operations (such as disposition and recycling of products containing
nanomaterials)
The possibility cannot be denied that workers engaged in any of these operations may

suffer from exposure to nanomaterials. According to the results of questionnaire research,which was, from September 2007 through to February 2008,

jointly conducted by theJapan National Institute of Occupational Safety and Health (JNIOSH) and the National
Institute of Advanced Industrial Science and Technology (AIST) (hereinafter referred to as“questionnaire results”), more than 50% of occupational health supervisors in workplaces
thought, almost all of working processes, both the possibility of leakage of nanomaterials
into the outside of the workplace during each production process and of worker’s exposure
to nanomaterials, although the percentage in a receiving process is relatively lower than inother processes.
The chance of human exposure to nanomaterials varies depending on the morphology
of nanomaterials, the state of nanomaterials, or operation methods for nanomaterials.
When particles of nanomaterials are being dispersed in liquid and the possibility ofemissions to air (caused by evaporation of liquid) can be reduced, or when nanomaterials
are being embedded in resins, etc. or immobilized in a bulk material, it can be thought that,in handling such nanomaterials, the chance of exposure will be greatly reduced.
Conversely, in handling nanomaterial powders, it can be considered that the chance of
exposure is significantly increased.
2 Items to Consider and the Results of Considerations (Associated with Each Measures)
By referring to the following measures, workplaces should strive to reduce exposure tonanomaterials on the basis of their actual conditions in terms of materials, processes, and18

transaction volume.
Enough basic data is not yet available to consider exposure prevention measures.
Under such disadvantages, using currently available data and knowledge, the following
separate measures have been provided which should be taken by relevant workplaces.
Therefore, if workplaces have some referential knowledge for preventive measures to betaken and further if, based on such knowledge, it is possible to take effective measures forpreventing exposure from the view of a precautionary approach, such workplaces may taketheir own response in spite of these measures shown below.
(1) Working Environment Managementa)

Assessment on the Measurement of Exposure Conditions (Exposure Assessment)
In order to understand the conditions of nanomaterials released into the working

environment or to confirm the efficiency of preventive measures against exposure to thenanomaterials, a quantitative analysis of nanomaterials in the working environment isnecessary. However, the measurement method of nano-sized particles has not been
established.
Measurement instruments used for nano sized particles include SMPS (Scanning
Mobility Particle Sizer), ELPI (Electrical low pressure impactor) , these devices canmeasure concentration by particle size or other low pressure impactors, CPC(Condensation Particle Counter), which can be used for measuring the total number ofparticles, DC (Diffusion Charger-based Surface-Area Monitor), which can measure the total
surface area of particles, or electron microscopes, which are used for the morphologicalobservation of collected particles.
Most of measurement instruments for nano-sized particles are usually large in size andexpensive. Therefore, in Europe and the United States, these instruments are not used formeasuring personal exposure which is the ordinary manner of working environment
assessment in those countries; oversea technical papers demonstrate that themeasurement of particles has been executed by sampling air from the working
environment. SMPS is expensive and does not have enough durability for measurementsthat are to be performed in the working environment. Recently, for CPC and DC, theirsmall-sized equipment is available, which can be brought into a workplace, but the
durability is unknown. When the durability of a measurement instrument is low, such
instruments will require frequent maintenance as a result of the measurement operation,
which is likely to become an obstacle for implementing measurements. Also, because therespective measuring device has limitations in performance, in some cases, only a single
19device may be insufficient.
The problem in measuring nano-sized particles is that various nano-sized particles exist
in workplaces. For example, in a workplace into which the external air flows, nano-sized
dust in the atmosphere may affect on the measurement results. Therefore, in such a case,
it is impossible to discern whether measurement values (including the number, weight, andsurface area of particles) are associated with the targeted nanomaterials. For the purposeof identifying nanomaterials, analysis of component needs to be made.
In the context of actual management of the working environment, it can be thought thatthe following four items need to be implemented: survey on raw materials; measurement ofa working environment; measurement of personal exposure; and more detailed survey on
nano-sized particles. Investigation of raw materials will require information provided by the
manufacturer, such as electron micrographs, particle size, and specific surface area.
With regard to the working environment management in workplaces, for the present, itis necessary to conduct the measurement of working environment as well as investigationof raw materials and to try to improve the working environment. If the conditions of theworking environment such as the location of or operations corresponding to a nano-sizedparticle emission source can be identified, these findings can serve as a reference inselecting a control measures and selecting/using protective equipment. For themeasurement of nano-sized particles, SMPS, CPC (as a relative densitometer), DC, andother small, portable measurement device should be selected and used depending on thecircumstances. If these devices are difficult to be used, a dust meter that can measureordinary size particles, i.e., particle counters should be used. Generally, in a working
environment, dust particles with a broad particle-size distribution exist, which are
generated from the same source. Therefore, even with a device that is not designed formeasuring nano-sized particles, the results of measurement in such working environment
are somewhat effective for the control of nanomaterials. Some of these measuring devices
are capable of automatically recording the concentration change over time, which may helpto evaluate correlation between working operations and concentration changes.
In addition, more detailed research on nano-sized particles will require the use of－TEM(transmission electron microscope), SEM (scanning electron microscope), SMPS, ELPI,
etc.
b

Location to be equipped with Enclosure needed
Definitions of terms for equipment and machinery are as follows. Any machinery used in

one of manufacturing processes for nanomaterials, is called “production equipment”. A
series of production equipment is called “production facility”. Also, a working facility
20

associated with manufacturing, as well as the production facility, is called “facilities”. A
structure in which facilities are located called “building”.
As an exposure preventive measure, except for cases where there is no possibility of
exposure to nanomaterials, for example, a nanomaterial is embedded into solid materials
such as resins or

is suspended in liquids (in a liquid case, measures for droplets arenecessary), in principle, manufacturing devices that emit nanomaterials must be enclosed.
Also, except in cases where there is no chance of exposure, in principle, enclosure,unmanning, and automation (hereinafter referred to as “enclosure, etc.”) must be applied to
all processed that involve direct handling of nanomaterials by workers－such as accepting
deliveries of raw materials; weighing raw materials and products; feeding into
manufacturing/processing

devices(including

mixingprocess);collecting

frommanufacturing/processing devices; repacking into containers,etc.; cleaning, inspections,and repairing of manufacturing/processing devices; and cleaning of containers－in order toprevent workers from exposure to nanomaterials. In particular, mixing of nanomaterial
powder with liquids or resins is highly likely to result in exposure to nanomaterials;
therefore, either enclosing, etc. or operations in a glove box must be adopted.
Moreover, even in the disposal of wastes or in recycling operations, when exposure tonanomaterials is possible, in principle, necessary measures (such as enclosure, etc.) must
be taken.
Additionally, when enclosure, etc. is difficult to be taken, a local exhaust ventilation
system, etc. (including push-pull type ventilation system: the rest stays the same) is
necessary to be installed to deal with this situation.
c Location to be Equipped with Local Exhaust Ventilation System
In a location where devices manufacturing and handling nanomaterials cannot have asealed structure, a local exhaust ventilation system, etc. must be installed to prevent
dispersion of nanomaterials. The following specific processes are included in theprocesses of manufacturing and handling nanomaterials and expected to fail to achieve
enclosing or automation; therefore, they must be equipped with a local exhaust ventilation
system, etc. These processes are:・ The following processes conducted at workplaces manufacturing nanomaterials where
dry nanomaterials need to be directly handled by workers;－ Processes of collecting synthesized nanomaterials (except for continuous and/or
automated processes)－Processes of weighing, packing, and packaging of produced nanomaterials
21

・ The following processes are conducted at workplaces handling nanomaterials in order toprocess and treat received, dry nanomaterials (including unpacking of containers andinputting into devices)－Unpacking process (a process and operations of unpacking shipper-packed containers
containing nanomaterials so as to facilitate the later feeding process)－ Dividing and weighing process (a process weighing and taking of a portion of
nanomaterials for the next feeding process)－Feeding process (a process of inputting nanomaterials into a hopper, etc.)
Even when the operation is to be performed with sealed production equipment or within
an enclosed system, access openings for maintenance and inspection must be equippedwith a local exhaust ventilation system, etc. or glovebags need to be used for suchoperation.
A booth-type hood is preferable for local exhaust ventilation systems. In a case where
the size of the production equipment is large, the installation of a push-pull type ventilation
system may be preferable for the convenience of workers.
In addition, after a local exhaust ventilation system, etc. is installed, it is critical toensure that the periodic maintenance checks are performed.
dMethod of Dust Removal from Exhaust Air
The outlet of a local exhaust ventilation system, etc. needs to be directly open to

outside air. In that case, to prevent emission of nanomaterials along with exhaust air, a
local exhaust ventilation system, etc. need to be equipped with high performance filters thatare capable of collecting such nanomaterials.
In selecting filters to be used, in consideration of the aggregation nature ofnanomaterials, the following points need to be investigated to select an appropriate filter
capable of collecting targeted nanomaterials. These points are: the diameter ofnanomaterial particles; the status of aggregation of nanomaterials; dust-catching
performance of filters, etc.
When such an investigation is not to be conducted, a HEPA filter or the equivalent
performance filter needs to be installed for exhaust filtration.
Performance of HEPA filters may vary depending on the diameter and aggregation
nature of a nanomaterial; however, the dust-catching efficiency of HEPA filters is thought tobe satisfactory for ordinary nanomaterials.
Also, prior to using HEPA filters, it should be noted that, regardless of the highperformance, these filters have a high pressure loss and they are disposable. Therefore,
22when using HEPA filters in large-scale facility, it is necessary to raise the performance ofelectric generators/exhaust fans and to perform the replacement of HEPA filters inoperations that may increase dust generation. In that case, it is important that prefilters are
installed in front of the HEPA filter to reduce filter load and the frequency of replacement of
HEPA filters.
Also, when a targeted substance can be adequately collected, use of electric dust
collectors might be selected.
(2) Working ManagementaContents of Operation Rules
In order to ensure that working operations can be properly performed to prevent theoccurrence of exposure to nanomaterials, it is essential that working specifications on
handling of nanomaterials must be prepared and adequate instructions must be given toworkers to allow them to follow the content of the specifications. Such working
specifications must contain information on the harmful effects of nanomaterials to behandled as well as information and other findings associated with the working environment.
bCleaning Method of Floors etc.
When cleaning floors and work benches in a workplace, the use of conventional

vacuum cleaners and brooms may end up causing further dispersion of nanomaterials into
the air. Therefore, it is required that cleaning operations should be performed by suctioning
nanomaterials vacuum cleaners with a HEPA filter or, when this is difficult or unsuitable tobe performed, by wiping with wet cloths. In this case, it may be effective to add moisture toaccumulated nanomaterials firstly and to wipe off them; however, in a case ofwater-shedding powder, introducing water may disperse the powder. Therefore, cleaning
operations need to be conducted in consideration of both the status of the workplace andproperties of the nanomaterial. In addition, cloths used in wiping must be placed into animpervious and hard-to tear bag and disposed in a proper way.
c

Prevention of Contamination in the Nanomaterial Workplaces and the Outside

Environment
Facilities that manufacture, process, and/or handle nanomaterials must be segregatedfrom the outside environment and also, a decontamination area in between to prevent
nanomaterials from being transferred outside of workplaces on work clothing.
In addition, unauthorized persons must be kept away from facilities manufacturing,processing, and/or handling nanomaterials.
23

d

When to Use RPE (Respiratory Protective Equipment)
Except in cases where there is no possibility of exposure to nanomaterials, when

workers are engaged in the manufacturing and handling nanomaterials, effective RPE
must be used by such workers. In implementing exposure preventive measures, enclosureof facilities, installation of a local exhaust ventilation system, and other facilitical measures
should be prioritized. If appropriate, depending on the circumstances (such as faciliticalmeasures), workers must select the most effective RPE.
In that case, in consideration of use in irregular or emergency situations, the required
number of appropriate RPE used for preventing inhalation of nanomaterials must be
stocked and kept clean and available.
e

Performance Requirement for RPE and Precautions for Use
Effective RPE to be used by workers must be as follows: air-supply respirators such as

supplied air-respirator; dust masks with a particle collection efficiency of 99.9% or higher,
or face piece-, face shield- or hood-type PAPR (powered air-purifying respirator) with aparticle collection efficiency of 99.9% or higher that is in compliance with JIS T8157.
Among these respirators, dust masks to be used must have national certification. In
selecting dust masks to be used, in consideration of the aggregation nature ofnanomaterials, the following points need to be investigated to select an appropriate dust
mask capable of collecting targeted nanomaterials. These points include: the diameter ofnanomaterial particles; the status of the aggregation of nanomaterials; dust-catching
performance of dust masks, etc.
Selections of RPE are given in the Appendix. In addition, RPE must be selected foreach workplace, for example, a workplace that requires explosion-proof measures, aworkplace that is in uncomfortable hot environment, or a narrow workplace, etc.
In selecting dust masks, after checking the adequacy of fit between a face piece andworker’s face, a face piece in good condition must be selected. Adequacy-of-fit tests need
to be performed every time the face piece is worn. In addition to that, maintenance,
inspection, cleaning, and appropriate storage of RPE are indispensable.
fRequirements for Protective Gloves and Precautions for Use
Where hand skin contact with nanomaterials is possible, protective gloves need to be

used. Protective gloves to be used must be made of appropriate materials to prevent
adherence of nanomaterials to the skin. Preferably, in order to maintain effective and clean
conditions, protective gloves should be disposable but it is not the case only if clean
24conditions can be maintained by washing, etc. Also, if used protective gloves are disposedof, such gloves must be put into appropriate bags to be disposed of adequately.
When protective gloves are put on or taken off, if skin contact with nanomaterials is
unavoidable or highly possible, it is necessary to wash hands with soap or wipe off the skinwith a cleansing cream.
g

When to Use Goggle-type Protection Glasses
If eye contact with powder, spills, etc., of nanomaterials may occurs, it is necessary to

use goggle-type protection glasses.
h

Use of Work Clothes and Precautions for Use
When nanomaterials are possibly adhere on work clothes, exclusive protective clothingneeds to be put on. Preferably, protective clothing should be made of unwoven cloth;
effective and clean conditions must be maintained by washing, etc.
Also, if protective clothing on which nanomaterials are deposited needs to be taken
outside of the facility, such protective clothing must be put into, for example, impermeable,
hard-to-tear bags to prevent the spread of exposure outside the facility.
i

Keeping of Operation Records
Operation records can serve as an information source to understand and improve thecurrent status of exposure preventive measures. Therefore, it is very significant to store
operation records on the manufacturing and handling of nanomaterials. Operation records
must be prepared that indicate by whom, when, and how the operation was performed andalso be retained for an extended period of time.
(3) Healthcare
Currently, little is known about the adverse effects of nanomaterials on human health.
Healthcare is the basics of occupational health management. Employers must implement
regular health examinations and recognize the present health conditions of the relevant
workers.
(4) Occupational Safety and Health Education
In order to increase the efficiency of preventive measures against exposure tonanomaterials, it is critical to ensure that workers engaged in the related operations should
understand the physical and chemical properties of nanomaterials, potential adverse
health effects, control measures for the working environment, the use of PPE (personal25

protective equipment), etc., and also should abide by manuals such as operational
procedures.
In particular, for RPE, it is important to select appropriate RPE fit for the conditions of
the working environment and/or the duty of the operation. Additionally, in order to reduceleakage between the face piece of RPE and wearer’s face, it is essential to ensure
continued adequacy of fit. Therefore, the related workers must be given detailed
instructions concerning the following: proper selection of RPE; a method on how to put on
the RPE; the method of leakage rate measurement based on the adequacy of fit between
face piece of respirators and face; method for checking adequacy of fit; and storage andmanagement of RPE.
(5) Response to Waste Disposal
Among wastes generated from workplaces manufacturing and handling nanomaterials,
those posing risks of nanomaterial dispersion must be placed into impermeable,
hard-to-tear bags and properly disposed of to prevent the dispersion of suchnanomaterials.
In a workplace where waste disposal is mainly undertaken or where recycling can be
implemented, after consideration of the possibility of nanomaterial dispersion in theworking environment and if there is any possibility of exposure, adequate measures(including facilitical measures, etc.) must be taken to prevent the workers from exposure tonanomaterials.
In addition, the treatment of nanomaterials needs to be performed in a manner or
condition fitting their nature and properties. Carbon nanotubes, for example, are found tobe pyrolytically decomposed at a temperature range from 750 °C to 850°C.
(6) Response to irregular Operations (repair of facilities, etc.)
Potential exposure to nanomaterials may increase during irregular operations such as
maintenance checks and/or refurbishment of production equipment that has been alreadyused for manufacturing or processing nanomaterials, and the cleaning of production
equipment or workplaces. Therefore, facilitical measures, such as local exhaust ventilation
systems, etc. must be taken at first. If the measures are extremely difficult to be taken, PPE(personal protective equipment) such as RPE must be used to prevent exposure tonanomaterials.
Additionally, operation records in non-stationary operations need to be prepared andretained for an extended period of time.

26

(7) OthersaMeasures of Preventing Fire and Explosion
As the size of a material approaches nanoscale, the specific surface area becomeslarger and the minimum ignition energy becomes smaller, which can make a relatively inert
material easily combustible. Dispersion of nanomaterials into the air may induce greaterrisks of explosion and fire than that of non-nanomaterials with the same components.
For preventive measures against explosion and fire caused by nanomaterials, the levelof useful knowledge still remains unsatisfactory. The reduction of dust concentration,
prevention of static charge generation, the reduction of oxygen concentration, etc. would
be considered as general measures.

These measures are necessary to be taken

depending on the property of nanomaterials to be used, facility manufacturing and handling
nanomaterials, related processes, contents of operations, etc.
b

Response to Emergency Situations
For responses to emergency situations, it is important to establish criteria for

determining emergency situations and to develop appropriate measures. For example,
after criteria for small spill and/or large spill are specified, when such a situation takes place,warnings need to be provided to peripheral workers that an emergency has occurred. Also,in that case, some operational procedures must be established to prevent workers fromexposure to the leaked nanomaterials.
Additionally, first aid measures to be taken in case of exposure are as follows:
Dust removal must be done in a clean-air environment;
If eye contact occurs, wash eyes thoroughly with water;
If inhaled, gargle or rinse mouth; andIf swallowed, (if possible) spit it out and then, gargle or rinse mouth
3 Further Advanced Study and Challenges to be Addressed(1) Study on Possible Health Effects of Nanomaterials
For the potential health effects of nanomaterials, many research institutes in Japan andother countries as well as OECD and other international institutions are currently engaged
in the elucidation of the mechanism, but, the useful scientific knowledge still remains
insufficient. In particular, the long-term effects of nanomaterial inhalation (which is thought
to be the primary exposure route in workplaces) on respiratory tracts and other organs
have not been yet clarified. Therefore, along with international cooperation, long-term
exposure tests with small laboratory animals and other necessary tests must be conducted
to gather useful information on the harmful effects of nanomaterials. These tests will mainly
27

focus on inhalation toxicity, which is assumed to be the actual route of exposure among
workers, and dermal toxicity. However, due to the abundance of different types ofnanomaterials to be studied, it is also important to promote research and development on
convenient, hazard screening tests.
In addition, when conducting risk assessments to extrapolate from test results to humanhealth effects, it is necessary to consider previously obtained data on other fibrous and/or
particle materials.
Other than by the collection of information on harmful effects using laboratory animals,
effects of nanomaterials on humans may be given by surveillance and analysis of the
medical check-up results of workers engaged in manufacturing and handling of suchnanomaterials. Therefore, if necessary, it is critical to establish a structure for effectively
surveying and analyzing not only the medical records but also the work operation recordsof relevant workers, etc.
(2) Establishment of Occupational Exposure Limit Standards
In order to implement working environment management, occupational exposure limit
standards must to be clarified. Therefore, it is important for the national government tosurely follow up on the results of foreign and domestic research on the potential harmful
effects of nanomaterials.
(3) Study on Engineering Measures for Preventing Exposure to NanomaterialsaStudy on Behaviors of Nanomaterials in the Working Environment
Although nanomaterials are known to be present in aggregated form, and studies on

their behaviors are underway, little is known about the following matter in actual
manufacturing and handling processes, that is size of nanomaterials aggregated andsuspended in the working environment, size distribution of nanomaterials, concentration of
nanomaterials and so on. Probably, these questions may have different answers
depending on the type of nanomaterials, but clarifying these questions must be necessary
to achieve both accurate measurement analysis and appropriate preventive measures for
exposure to nanomaterials. Therefore, in-depth research must be moved forward throughinternational cooperation. And also, obtained knowledge and information should be sharedacross the world and utilized for similar exposure prevention measures in other countries.
b

Development of Measurement Methods, Measurement Equipment, and Estimation

Technique for Nanomaterials
The most significant challenge for nanomaterial measurement is to develop
28measurement methods and measurement equipment, both of which are easy to implement
in workplaces. Relevant authorities including private organizations should actively advancethe development of highly durable, user-friendly small equipment that can be easily
brought into operation sites.
Even if the development of such equipment succeeds, considering the fact that there
still remain many obstacles for ordinary workplaces to measure nanomaterials, it could be
important to develop, instead of actually measuring the concentration of nanomaterials, apractical methodology to estimate such concentrations in order to put forward exposure
preventive measures.
c Engineering Measures for Preventing Dispersion and Exposure
As a preventive measure against exposure to nanomaterials that is associated with the
manufacturing and handling of them, a local exhaust ventilation system, etc. plays animportant role. Therefore, it is necessary to collect and organize practical information on
the effectiveness of general exhaust ventilation systems as well as information on theeffectiveness of other type ventilation systems in terms of the correlation between their
type/performance and actual conditions of intended use in workplaces. Such informationand findings need to be provided by each workplace in a timely and accessible manner.
dCollection of Information on the Performance of Dust Removal Devices
For filters and dust removal devices used for the removal of exhaust air from local

exhaust ventilation systems, etc., more advanced studies seem to be required. Among thevarious types of filters, the performance of HEPA filters has been relatively elucidated. It isthought that nanomaterials can be captured with this HEPA filter, but the detailed
knowledge about nanomaterials on type- and size-basis still remains unsatisfactory. The
shortage of data on other type filters and dust removal devices is more pronounced.
Nanomaterials vary in size and in electrical properties depending on the type and also, theyoften exist in aggregate form. Until collection of nanomaterials can be achieved using filters
etc., there still remains many unknowns. Thus, for the purpose of easily selecting effective
dust removal devices, it is necessary to gather and organize empirical knowledge forelucidating a dust removal device on the basis of the type and state of nanomaterials. Suchknowledge and findings need to be provided by each workplace in a timely and accessible
manner.
ePrevalence of Effective RPE
Currently, development of filters for dust masks has been underway. Preferably, in the29

future, necessary knowledge should be further gathered and also, more detailed
information should be continue to be provided about the collection efficiency of a filter thatis expected to be appropriate for each operation.
Also, the leakage rate of dust masks in wearing RPE might differ between
nanomaterials and micro/macro-sized dust particles. Therefore, leakage rates fornanomaterials will need to be elucidated.
In this context, standard requirements to be met should be considered for respirators
exclusively used for nanomaterials.
(4) Improvement of Structures for Transmitting Information to be Provided inTransferring/Providing Nanomaterials
In order to take preventive measures for exposure to nanomaterials in a relevant
workplace, such a workplace must clearly understand what it is handling in relation tonanomaterials. To that end, it is indispensable to transmit and share information among
relevant workplaces. Based on Article 57-2 of the ISHL, for some types of nanomaterials
and formulations containing such nanomaterials, when they are transferred or provided,
the shipment must be accompanied with a document stating the name, ingredients, etc. ofthe substance (MSDS). In this provision, however, not only information to be provided is
not specific to nanomaterials, but also other type nanomaterials are not obliged to deliver
the MSDS.
Among nanomaterials, with regard to a substance for which MSDS must be provided, it
can be considered that, when the substance exists in nanoscale, the fact and precautions
for handling should be reflected in its MSDS to transmit the relevant information. Similarly,
even in a case where such an MSDS does not have to be provided, informationtransmission must be required. For nanomaterials, as well as voluntary countermeasuresby manufactures, reliable information transmission models (including the reflection of
information into MSDS) must be further developed.
(5) Considerations of Handling Nanomaterials Associated with Research into Chemical
Substance Hazards
According to the ISHL, when a newly developed nanomaterial is composed of novel
matter with nanoscale dimensions that cannot fit into any category of existing chemicals,such a nanomaterial must be notified as a new chemical substance and subject to theimplementation of a health hazard survey under Article 57-3 of the Law. But, information
submitted for the existing chemical notification system is not specific to nanomaterials.
In contrast, when newly developed nanomaterials are composed of existing chemical
30

substance(s), under the current ISHL, such nanomaterials are, regardless of theirnanoscale size, classified as “existing chemicals” and also, fail to fall within the category of
notifiable substances. This is because the ISHL classification does not focus on the shapeand size of a chemical substance.
However, it is well known that matter reduced to the nanoscale can exhibit uniqueproperties compared to what they have on a micro/macroscale. In addition, there remains apossibility that nanomaterials may show different aspects of adverse health effects than
micro- and macro-materials do. Apparently, current approaches for handling of
nanomaterials need more consideration. In this context, we must understand how muchscientific knowledge has been accumulated and take note of the progress of discussions
among international institutions and keep up with regulatory trends on chemical substancemanagement specified by other domestic regulations. With the exception of nanomaterials
that have been already developed and currently manufactured and handled, when a novel
nanomaterial is supposed to be developed in the future as a new chemical substance,
and/or when a nanoscale material is expected to be newly developed from existingchemical substance(s), any of such cases must be separately considered on how to handle
them under the ISHL.
(6) Collection and Provision of Information on Nanomaterials
Information gathering should focus on not only information provided from research anddevelopment on nanomaterials and research on the potential health effects ofnanomaterials, but also various types of information provided from relevant workplaces, so
as to allow such information to be utilized for preventive measures.
In addition, as provided for by Article28-2 of the ISHL, for nanomaterials as well as forother materials, employers must endeavor to investigate the danger or harm, etc. and takenecessary measures based on the results of investigations. In order for this to be properly
observed, the national government needs to strive to collect the best examples and publicly
announce their findings to ensure extensive dissemination of the provision.
Although related information on nanomaterials has been already provided on thewebsite of JNIOSH (National Institute of Occupational Safety and Health, Japan), it isessential that further improvement of the functionality and contents of JNIOSH’s website
should be accomplished to ensure that their website becomes more accessible and helpful
to users.
Other than information dissemination over the Internet, it is also important to provide
information by utilizing leaflets, public relation magazines issued by relevant organizations,and a variety of other ways.
31

(7) Collaboration with the Relevant Ministries
As for collaboration with the relevant ministries, the Cabinet Office plays a central role inexchanging and sharing of information among the related ministries and agencies. In the
future as well as at present, in collaboration with the relevant ministries and the relatedorganizations, the government needs to continue promoting experiments and research on
nanomaterials and sharing the useful related information.
Part 5Afterword

Nanomaterials posing unknown risks to human health, including their properties, still do
not reveal themselves. In this report, despite the lack of detailed knowledge about
nanomaterials, by considering them from the viewpoint of a so called “precautionary
approach” and organizing present knowledge on the applications, production volume, andnature of nanomaterials, these exposure preventive measures have been provided, which
was considered to be the most appropriate solution at present.
As interim preventive measures against labour accidents associated with nanomaterials,
solutions considered here should be applied to actual situations in workplaces. In addition
to that, it is important that, with the understanding of actual measures taken in workplaces
and of the current status of the workplaces, international support and cooperation should
be a driving force not only to promote further investigations and R&D on matters that havenot been yet elucidated and/or that have made less progress in technical development but
also to reflect the obtained results in the present measures.

32

Appendix:

Method for the Selection of Respiratory Protection Equipment

When using respiratory protection equipment (RPE), it is necessary to select RPE with
an appropriate protection factor (PF) corresponding to the level of occupational safetymeasures at the facility or with assigned protection factors (APF). PF is a value that
represents the protection performance of RPE and can be defined by the following
equation:
PF= Co/Ci

PF： Protection Factor
Co ： Dust concentration outside facepiece, etc.
Ci ： Dust concentration inside facepiece, etc.

The above equation shows－the higher the PF, the less likely dust particles would leakinto the respirator－ such RPE can be considered to have a low potential for worker
exposure. If it is impossible to make measurement of the PF in workplaces, assigned
protection factors (APF) provided by the respective competent authority should be used.
APF is a representative value of multiple protection factors measured within a laboratory.
APF is also a minimum expected value that would be obtained when trained wearers
put on properly functioning RPE correctly. Table 1 shows assigned protection factors thathave been publicly announced by the US and Japanese competent authorities.
When selecting RPE, in a case where, at industrial production sites, adequate faciliticalmeasures cannot be taken on the basis of occupational health engineering and further,
exposure to high concentration of nanomaterials can be expected, RPE with a higher APF
should be selected. When it is possible to take appropriate measures such as theenclosing, automation, and remote-handling of production processes, RPE with a smaller
APF can be selected. Also, when it is not possible to perform enclosure, etc. of production
processes but possible to install local exhaust ventilation system, etc., this case falls in
between the previous two cases and thus, RPE with an intermediate level of APF should
be selected. When selecting RPE to be used for testing and research institutes, in a casewhere adequate facilitical measures cannot be taken on the basis of occupational healthengineering and further, exposure to high concentration of nanomaterials can be expected,
RPE with a higher APF should be selected. When it is possible to take measures(enclosure, etc.) and/or to install a local exhaust ventilation system, etc., RPE with smaller
APF should be selected to respond to this event. Based on these concepts, information on
the selection of RPE for common workplaces manufacturing/handling nanomaterials andtesting/research institutes is provided, for reference purpose, in Fig.1 and Fig. 2 and in33

Table 2.
In preparing these Figures and Table, the following matters were taken into
consideration:
・If the results of working environment measurement, etc. cannot confirm whether there areno potential risk for worker exposure, even when handling nanomaterials in an enclosed
system, it was determined that RPE should be put on.
・Recent literature indicate that, in some filter media used for RPE, a particle diameter ofaround 50nm results in lowering the collection efficiency of the filter media, and that evenN95 (NIOSH standard：collection efficiency of 95% or higher) or S2 (National Standard for
Dust Respirator Certification Test：collection efficiency of 95% or higher) filter media did fallshort of the standard value of 95% in collection efficiency. Therefore, as filter media for dust
masks, this document adopts filter media with a collection efficiency of 99.9% or higher, as
specified in the previous notification (as of February 7th, 2008).
Meanwhile, these Table and Figures have been prepared based on currently available
information and scientific knowledge. Therefore, the selection criteria for nanomaterials will
have to be reviewed at all future stages where we can characterize: what hazards
nanomaterials pose; what level the environmental concentration and/or worker exposure
concentration of nanomaterials is present; and how much the collection efficiency changes
depending on the particle diameter of filter media used for dust masks.

34

Fig. 1 RPE Selection Chart for
Common Workplaces Manufacturing or Handling Nanomaterials
Works forhandling nanomaterials

Specialized operations, particularly where
facilitical measures cannot be taken on the basisof occupational health engineering and further,high concentration exposure can be expected[Example of Works]• Equipment cleaning operation• Collecting & recycling products• Others• Enclosure, automation & remotecontrolling of manufacturing processes• Use of nanomaterials in liquid form

YESNO
Installation of a local exhaust ventilation or
push-pull type ventilation system

YES
Level at which Little Exposure can be Expected[ Selection of RPE ]– standards in selection & specific examples –Select RPE with a level of APF of 10 (the following RPE)
or with a higher protection performance• Replaceable, half-face type dust mask (national test
passing products: particle collection efficiency of 99.9% orhigher)• Disposable dust mask (national test passing products:
particle collection efficiency of 99.9% or higher)NO

Level at which Low Exposure can be Expected

Level at which Exposure can be Expected[ Selection of RPE ]– standards in selection & specific examples –Select RPE with a level of APF of 50 (the following RPE)
or with a higher protection performance• half facepiece, fan-assisted air-purifying respirator(particle collection efficiency :99.9% or higher)• Supplied-air respirator (half-face, continuous flow typeairline mask or hose mask with electric blowers)• Replaceable, full-face type dust mask (national test
passing products: particle collection efficiency of 99.9% orhigher )[ Selection of RPE ]– standards in selection & specific examples –Select RPE with a level of APF ranging from 100 to 1,000• Full facepiece and hood type fan-assisted
air-purifying respirator (particle collection efficiency :99.9%
or higher)• Supplied-air respirator (full face type and hood type,continuous flow airline mask or hose mask with electric
blowers)
Select RPE with a level of APF 1,000• Pressure demand-type airline mask

However, if:• Oxygen concentration of lower than 18%(works that may suffer from lack of oxygen)

Select supplied-air respirators (Both dust mask and fan-assisted air-purifying respirator are unsuitable for this case)• Works under the conditions of coexistence oforganic solvents and hazardous gases

Select supplied-air respirators or chemical cartridge respirators with dust proof-filters (particle collection efficiency: 99.9% or higher)(Fan-assisted air-purifying respirators are unsuitable for this case)• Department performing works necessary forthe use of explosion-proof RPE

Select supplied air respirators or dust masks (Fan-assisted air-purifying respirators are unsuitable for this case)35

Fig. 2 RPE Selection Chart for
Testing and Research Institutes
Works forhandling nanomaterials
Specialized operations, particularly where
facilitical measures cannot be taken on the basisof occupational health engineering and further,high concentration exposure can be expected[Example of Works]• Equipment cleaning operation• Others• Enclosure, automation & remotecontrolling of manufacturing processes• Use of nanomaterials in liquid form

NO

YES

Installation of a local exhaust ventilation or
push-pull type ventilation system

YES

NO

Level at which Little Exposure can be Expected

Level at which Exposure can be Expected[ Selection of RPE ] – standards in selection & specific examples –Select RPE with a level of APF of 10 (the following RPE) or with a higher protection
performance• Replaceable, half-face type dust mask (national test passing products: particle
collection efficiency of 99.9% or higher)• Disposable dust mask (national test passing products: particle collection
efficiency of 99.9% or higher)[ Selection of RPE ] – standards in selection & specific examples –Select RPE with a level of APF of 50 (the following RPE) or with a higher protection performance• half facepiece, fan-assisted air-purifying respirator (particle collection efficiency :99.9% orhigher)• Supplied-air respirator (half-face, continuous flow type airline mask or hose mask with electric
blowers)• Replaceable, full-face type dust mask (national test passing products: particle collection
efficiency of 99.9% or higher )Select RPE with a level of APF ranging from 100 to 1,000• Full facepiece and hood type fan-assisted air-purifying respirator (particle collection
efficiency :99.9% or higher)• Supplied-air respirator (full face type and hood type, continuous flow airline mask or hosemask with electric blowers)
Select RPE with a level of APF 1,000• Pressure demand-type airline mask

However, if:• Oxygen concentration of lower than 18%(works that may suffer from lack of oxygen)

Select supplied-air respirators (Both dust mask and fan-assisted air-purifying respirator are unsuitable for this case)• Works under the conditions of coexistence oforganic solvents and hazardous gases

Select supplied-air respirators or chemical cartridge respirators with dust proof-filters (particle collection efficiency: 99.9% or higher)(Fan-assisted air-purifying respirators are unsuitable for this case)• Department performing works necessary forthe use of explosion-proof RPE

Select supplied air respirators or dust masks (Fan-assisted air-purifying respirators are unsuitable for this case)36

Table 1 :Assigned Protection Factor (APF) for Respiratory Protective Equipment (RPE)
OSHA 29
CFR
1910.134(2006)

NIOSH
Decision
Logic(2004)

ANSI
Z88.2
e
(1992)

Disposable type

10

10

10

5

Half face type mask

10

10

10

10

50

10

100

50d
d

Type of Respirators

Air-purifying
Respirator (APR)

Full face type

With
N/P/R 100 filter
Without
N/P/R 100 filter

ANSI
JIS T8150:(Draftf
2006
revision)g3 - 104 - 50g

50

50

100

50

Half face type

50

50

50

50

4 - 50

Full face type

1000

50

1000b

1000

4 - 100

Helmet/hood

25/1000a

25

1000b

1000

4 - 25

25

25

25

25

4 - 25

Half face type

10

10

10

----

10

Full face type

50

50

100

----

50

Half face type

50

50

50

250

50

Full face type

1000

50

1000

1000

100

Helmet/hood

25/1000a

25

1000

1000

25

Loose-fitting
facepiece

25

25

25

25

25

Half face type

50

1000

50

250

50

Full face type

1000

2000

1000

1000

1000

Pressure demand, combination supplied-air/SCBA
full-face respirator

----

10000

----

----

1000

Half face type

10

----

10

----

10

Full face type

50

50

100

----

50

Helmet/hood

50

----

----

----

―

Full face type

10000

10000

10000c10000c5000

Helmet/hood

10000

----

----

10000c―

Fan-assisted
Air-purifying
Respirator

Loose-fitting facepiece

Demand type

Supplied-air
Respirator

Continuous
flow typePressure
demand typeSelf-Contained
Compressed Air
Breathing
Apparatus (SCBA)

Demand typePressure
demand type
a

b
c
d

e
f
g

The employer must retain not only test results for these RPE but also the manufacturer’s certificate indicating thatthe protection factor is 1000 or higher.
HEPA should be used for protection from particles. Where the filter media is not HEPA: APF = 100
Only for planning emergency measures.
When a leakage rate is checked through quantitative fit test (using mask fitting testers), a PF of 50 is adopted, whenthrough qualitative fit tests, the PF is to be regarded as 10.
Declared invalid in 2003
A minimum level of PF that is expected only when the RPE functions normally.
Protection factors for APR can be calculated from the formula,”100/ (Lm + Lf)”, where [Lm (%)] is the leakage rate ofrespiratory inlet covering and [Lf (%)] is the permeation rate of the filter of APR

37

Table 2. Selection of Respiratory Protective Equipment (RPE) in Handling Nanomaterials (Conclusion)

Place of Use

Enclosing, Automation,

Installation of a Local Exhaust

Remote Controlling, andVentilation and Push-pull

Fluidization

Ventilation System

APF of 10 or Higher

APF of 50 or Higher

Without Engineering
Measures

Common Workplaces for
manufacturing and Handling

APF of 100 or Higher

Nanomaterials
Testing and ResearchInstitutes

APF of 10 or Higher

APF of 50 or Higher

However, If:
Working Environment Conditions

Selection of RPE

Workplaces with Oxygen Concentration of Lower than 18%

Supplied-air Respirator

Works under the Conditions of Coexistence of Organic

Supplied-air Respirator or Chemical Cartridge Respirator with

Solvents and Hazardous Gases

Dust-proof Filter

Works Requiring the Use of Explosion-proof RPE

Supplied-air Respirator or Dust Mask

38