VOC Emission Rate Specification for
Personal Computers and Tablet Devices (Ver. 1)

January 2014

Japan Electronics and Information Technologies
Industries Association

Contents

1. Background and purpose of establishing Specification……………………… 1

2. Scope………………………………………………………………………………… 2

3. Normative references……………………………………………………………… 3

4. Terms and definitions…………………………………………………………… 4

5. Criteria for VOC emission rates………………………………………………… 7

6. Measurement method of chemical emission rate……………………………… 8

7. Commentary……………………………………………………………………… 12

Annexes……………………………………………………………………………… 19

Revision History
September 2005 Issued “VOC Guideline for Personal Computers (Ver. 1).”March 2008

Issued “VOC Guideline for Personal Computers (Ver. 2).”Main revisions○ Revised the measurement method.
・Made sampling timings consistent with international standard ISO/IEC 28360.
・Added Windows Vista to the power-saving mode settings in the Power Options
Properties figure.

March 2011

Issued “VOC Emission Rate Specification for Personal Computers (Ver. 1).”Main revisions○ Changed the document name.
○ Reviewed the scope.
・Specified the display size.
・Added tetradecane as an optional target substanceJanuary 2014

Issued “VOC Emission Rate Specification for Personal Computers andTablet Devices (Ver.1).”
Main revisions○ Revised scope of application.
・Added tablet devices to the range of equipment covered.

1

Background and purpose of establishing Specification

Recently, buildings are more tightly sealed and insulated than ever, causing indoor air pollutants(e.g. chemical substances) from the living environment. This has resulted in “sick house (building)
syndrome”, a situation that occupants suffer from health problems such as headaches and dizziness.
Since the l980s, volatile organic compounds (VOCs) and aldehydes emitted from furniture andbuilding materials have been major issues, and various measures have been researched and developed
to suppress these substances. VOCs emission from other sources, including daily commodities, hasalso been highlighted lately.
In 1997, the 8Ministry of Health, Labor and Welfare (MHLW) established the indoor concentration
criteria for formaldehyde as measures to combat "sick house syndrome” and the Committee on Sick
House Syndrome (Indoor Air Pollution) was established to work on the supplementation andexamination of the indoor concentration criteria.
The Ministry of Education, Culture, Sports, Science and Technology partly revised the Standards ofSchool Environment and Health in 2002, in which formaldehyde and VOCs (toluene, xylene, andp-dichlorobenzene) concentrations were added to the inspection items of the air environment tomaintain and improve sound indoor environment in school classrooms according to the criteria. And it
was made obligatory to ensure that the indoor concentration level should not exceed the indoor criteria
before introducing school equipment, including computers. Therefore, it was made mandatory forschool equipment vendors to submit data about VOCs and aldehydes emission from the equipment
and ensure that the indoor concentration level should not exceed the criteria. The Standards for School
Environment and Health were revised in 2004 again, and currently six substances (ethyl benzene andstyrene have been added) are covered by the regulation. In accordance with the enforcement of the
School Health and Safety Act in 2009, the new Standards for School Environment and Health went
into effect.
In 2004, the Small Chamber Method was standardized in JIS for determining emissions frombuilding materials. Since there was no agreeable method for determining emissions from IT
equipment in Japan, however, companies established their own test methods and criteria to deal withthe situation.
In addition, some reports by the mass media gave the public a false impression that VOCs emission
from PCs alone exceeded the indoor concentration criteria. Since the PC industry needed to eradicate
this false impression, the IT Product Environment Committee organized the VOC Task Force andformulated this guideline in September 2005 to establish a standardized determination method andemission rate criteria, as well as to enlighten the public that the PC industry is making voluntary efforts
to curb VOC and aldehyde emissions from PCs.
Then in September 2007, ISO/IEC 28360 “Determination of Chemical Emission Rates from
Electronic Equipment” was established as an international standard for methods of measuringchemical substance emission rates. This ISO standard applies to copiers, information processing
equipment, and digital home appliances, including PCs and displays. In Japan, JIS C 9913:2008“Measuring method of volatile organic compounds and carbonyl compounds emissions for electronicequipment — Chamber method” consistent with ISO/IEC 28360 is now being drafted.
Under these circumstances, the VOC Task Group of JEITA, taking over the activities of the VOC
Task Force, made the VOCs emission rate determination method in the guideline consistent with
ISO/IEC 28360. Accordingly, JEITA revised this guideline to Ver. 2.
Recently, display screens have been getting larger and larger. However, the display size in thisdocument is specified in view of the installation conditions because it is assumed that 40 machines
are used in a PC laboratory. “VOC Emission Rate Specification for Audio and Visual Equipment”
was issued in 2010, but there was some discrepancy in the target substances due to different use
1

conditions. Thus, JEITA ironed out those differences and reviewed the target substances. Then the
document name was changed from “VOC Guideline for Personal Computers” to “VOC Emission
Rate Specification for Personal Computers (Ver. 1).”
In 2014, tablet devices, which have spread rapidly in the past several years, were added to therange of equipment covered due to their increasing use in the classroom. The specification wasretitled "VOC Emission Rate Specification for Personal Computers and Tablet Devices (Ver. 1)."

2

Scope

。
2.1 Applicable equipments
This document applies to Desktop PCs (including keyboard and mouse), All-in-One PCs(including keyboard and mouse), Laptop PCs, Tablet Devices, and Displays.
Each PC category includes Thin clients. However, those sold as servers and 30-inch or larger
displays are excluded from this document. Also, application to tablet devices is optional, sincetablet devices are battery-powered and some models may be unable to meet testing conditions; forexample, it may not be possible to configure them to operate continuously for the length of timerequired for testing.
2.2 Applicable substancesThis document applies to the seven substances listed in Table 2, which are the six substances
specified in the Standards for School Environment and Health plus acetaldehyde. Tetradecane,which is subject to the criteria for indoor air concentration stipulated by the Ministry of Health,
Labor and Welfare, is an optional substance.
Table 1 Substances to be measured
Substance
TolueneXylenep-Dichlorobenzene
Ethylbenzene
StyreneFormaldehyde
Acetaldehyde

Specified inStandards for School
Environment and Health
Ditto
Ditto
Ditto
Ditto
Ditto
Ordinances, etc.

Remarks
VOC
VOC
VOC
VOC
VOC
Aldehyde (VVOC)
Aldehyde (VVOC)

2.3 Start of application
This document starts to apply from when each company is ready to measure.

2

3

Normative references。
ISO/IEC 28360:2007, Determination of chemical emission rates from electronic equipment
ISO 16000-3:2001, Indoor air – Part 3: Determination of formaldehyde and other carbonylcompounds – Active sampling method (MOD)ISO 16017-1:2000, Indoor, ambient and workplace air - - Sampling and analysis of volatile organic
compounds by sorbent tube/thermal desorption/capillary gas chromatography- - Part 1: Pumped sampling3

4

Terms and definitions

For。
the purpose of this document, the following terms and definitions apply.
(1) VOC
Abbreviation of volatile organic compounds, a generic term for organic compounds withvolatility. In this document, VOCs are defined as volatile organic compounds that are identified
between n-hexane and n-hexadecane when indoor air is gas chromatographed on a non-polar
column.
(2) Aldehydes
Aldehydes are a generic term for organic compounds containing aldehyde groups. In general,they are formed by oxidizing alcohol and susceptible to further oxidization to form a carboxylic
acid. Aldehydes are very useful as a raw material for various reactions because of great reactivity
in the addition of carbonyl group (C = O) and the replacement with carbonyl group α -carbon.
(3) Criteria for indoor air concentration
The criteria for indoor air concentration as a “Guideline for indoor air pollution” establishedby the Committee on Sick House Syndrome (Indoor Air Pollution) of the Ministry of Health,
Labor and Welfare (MHLW). The criteria are not the legal requirement values, but used as atarget of indoor air quality. For more details, refer to the following URL. Annex 2 gives anabstract for reference.
(http://www.mhlw.go.jp/houdou/2002/02/h0208-3.html )(4) Standards of School Environment and Health
The management criteria established by the Ministry of Education, Culture, Sports, Scienceand Technology to conduct proper environmental health tests, follow-up measures and daily
environmental health management based on the School Health Law, and to maintain and improve
school environmental health. These standards specify inspection items, inspection methods,
criteria, and follow-up measures for each living environment (including illumination, noise,
facilities, and equipment) and hygienic environment (including air, water quality, feeding service,
harmful insects, and vermin). Regarding the air environment such as classrooms, there is a
specification on formaldehyde and volatile organic compounds. For more details, refer to thefollowing URL.
(http://www.mext.go.jp/a_menu/kenko/hoken/1292482.htm )(5) EUT
A generic term for Equipment Under Test. Functional and compete, including consumables
and accessories if applicable, ICT or CE equipment, from which chemical emission rates are
determined as specified herein.
(6) Environmental chamber
The container or room used to measure chemical substances such as VOC emitted from EUT in
the air, in which an EUT is placed. In this document, it is used to determine infinitesimal amountsof chemical substances emitted from IT equipment, and features the following performance.
a) To remove air pollutants from the ambient air.
b) To remove VOCs and other substances generated from the living environment.
c) To control the indoor conditions such as air flow rate and temperature.
d) To measure VOCs emission from IT equipment.
(7) Thin clients
Security-oriented terminal used in a business information system. It has a system
configuration in which the capabilities of a client are limited to the minimal functions so thatsources such as application software and files are managed on the server.
As for hardware, some clients have no built-in HDD, with a CF card mounted and the OS on
4the client, which is not writable. Others have no CF card mounted and the OS is loaded on theserver. In either case, the thin client cannot function in isolation.
(8) Room ventilation rate
The number of times per hour (h-1) when the air in a given room volume is exchanged withfresh ambient air through a ventilation fan, etc.
(9) Predicted maximum concentration
Given a constant emission rate from a product, constant room volume, and constant room
ventilation rate, the mean concentration of the atmosphere in the relevant room increases
rapidly with time, then converges to the constant value. This final value (μg/m3) is called thepredicted maximum concentration.
(10) Air volume
The capacity (m3) of a building that requires ventilation, which is obtained with an actual
gross floor area (m2) multiplied by the mean height to the ceiling (m). The actual gross floorarea means a gross floor area (sum total of the floor area of each story) with consideration ofvaulted areas and ceiling height. The mean height to the ceiling means the height to the ceilingwith consideration of the vaulted areas and hanging of the roof.
(11) Chamber air exchange rate
The ratio of the volume of clean air brought into the environmental chamber per hour to thevolume of the chamber itself. This is expressed by frequency of air exchange per hour (h-1).
(12) Emission rate
The mass of each substance [lμg/(h·unit)] emitted from the EUT per unit time.
(13) Relative humidity (rH)
One of the scales to indicate the amount of water vapor in the air (humidity). This scale
indicates the degree of saturation by (e/es)×100 (e: vapor partial pressure, es: saturated vapor
pressure), and is expressed as the percentage of vapor partial pressure to saturated vapor
pressure. In general, “humidity” refers to relative humidity.
(14) Background concentration
The concentration in the chamber with no EUT. Sometimes the air concentration that failed
to be filtered out (e.g. the ambient air concentration due to air pollution, the indoor
concentration due to emission from interior materials, and the residual concentration in thechamber from the previous measurement) may be mixed in the collected air, and may affect themeasurement results. Therefore, the background concentration shall be pre-determined, and thedetermined concentration with the EUT subtracted from this background concentration shall be
adopted as the concentration of emitted substances.
(15) DNPH cartridge
DNPH stands for 2,4-dinitrophenylhydrazine, and a DNPH cartridge is filled an absorbent
impregnated with 2,4-DNPH. By allowing the air to flow through this cartridge, aldehydes canbe collected as hydrazone derivatives.
(16) Carbonyl compounds
Among all the compounds having a carbonyl group (C = O), aldehydes, ketones, andketenes are called carbonyl compounds. Those compounds in which the carbon (C) of the
carbonyl group is joined to atoms other than carbon (C) and hydrogen (H) (e.g. oxygen (O) or
halogen) are not called carbonyl compounds.
R
R
H
C＝O
C＝O
R’
R
Aldehyde group
Ketone group(17) Carbonyl compounds DNPH derivatives

R’

C＝C＝O

Ketene group5

The aldehydes that are derivatized with DNPH compounds. The DNPH-derivative
compounds shall be separated and analyzed in a liquid chromatograph.
(18) High performance liquid chromatograph
The method used for aldehydes analysis. The typical analytes are organics dissolved in asolvent, and this method is commonly used to separate and identify the components ofbiological materials such as amino acids. Each element in the sample injected into the eluant(the mobile phase) sent with the liquid delivery pump is separated mutually while passing
trough the packing material (the stationary phase) in the column (separation tube), and which
is detected and determined with a detector connected to the column outlet. For packing
materials, porous materials such as silica gel, alumina, and polystyrene are used, and an
ultraviolet-visible spectrophotometer or a fluorescence detector or the like is used as adetector.
(19) Tenax tube
A hard glass or stainless steel tube with a 4-mm diameter filled with granular absorbent such
as Tenax-TA, Tenax-GC, and Carbon-Molecular-Sieve. VOCs in air are absorbed andcondensed by driving the air to be measured through this tube. Then, inert gas such as helium
is passed through the tube while heated, so that the absorbed materials are desorbed
quantitatively, and introduced to an analytical equipment such as GC/MS.
(20) Thermal desorption equipment
The equipment by which the heat is rapidly applied to the sample to volatilize, and theabsorbed material is desorbed from the absorbent boundary.
(21) Gas chromatograph mass spectrometer
An analytical equipment combining a gas chromatograph as a separation method and mass
spectrometer as a qualitative and quantitative method for low-boiling organic compounds.
After being heated and volatilized, the sample is resolved into its compounds by a gas
chromatograph and introduced to a high vacuum mass spectrometer. The molecules are ionizedand dissociated simultaneously in the mass spectrometer, thus producing fragment ions. Since
the resultant molecular ions and fragment ions are specific to each molecule, the components
can be qualified and quantified.
(22) ECMA328
Standard for the detection and determination of chemical emission from electronicequipment.

6Criteria for VOC emission rates

5。

5.1 Concept for setting criteria
The criteria by the Ministry of Health, Labor and Welfare are specified as indoor concentrations(µg/m3). However, VOCs emission from PCs has to be determined based on the emission rate per
product. Thus, the emission criteria are defined by using the following formula, expressing "therelationship between the indoor concentration and the emission rate."
Given that V is the room volume (m3), n is the ventilation rate(h-1), SER is the emission rate ofeach substance from one PC per hour (µg/h･unit), u is the number of PCs installed (unit) per room,and that the emission rates from PCs are constant with time, the maximum indoor concentrationthat can be expected, or the predicted maximum concentration Cmx(ug/m3) can be expressed by thefollowing formula.
Emission rate per hour (SER) [μg/(h·unit)] × Number of PCs installed (u) (unit)

Predicted maximum=
concentration (Cmx) (μg/m3)

Room volume (V) (m3) × Ventilation rate (n) (h-1)
Among PC classroom at a school, office, and home where PCs are installed, PC classroom is
expected to have the minimum air volume per product and the maximum concentration of the sevenemitted substances in the atmosphere, judging from the room volume, the ventilation rate, and thenumber of PCs installed Therefore, the condition of an average PC classroom at a school waschosen as a model in this guideline. The specific condition is as following.


Room volume: 180 m3 (based on the Standards for School Environment and Health)
Ventilation rate: 2.2 times/h (based on the Standards for School Environment and Health)Number of PCs installed: 40 (one PC per student)[Reference]
The ventilation rates are specified in the Standards for School Environment and Health asfollows:
Kindergarten/elementary school:
2.2 times/h or more
Junior high school:
3.2 times/h or more
Senior high school, etc.:
4.4 times/h or more
When the above formula is used to calculate the predicted maximum concentration, the emission
criteria are determined assuming that the PCs would contribute to the share of approximately 10%of the Standards of School Environment and Health or the criteria for indoor air concentration by
the Ministry of Health, Labor and Welfare.
5.2 Emission criteria
The emission rate determined in accordance with Section 6 " Measurement method of chemical
emission rate " shall be equal to or below the emission criteria specified in Table 2.

Table 2 Emission criteria (Emission rates from product)*1
7

[Unit: μg/(h·unit)]
Substance
Laptop PC
All-in-One PC
Desktop PC*2
Display*2
Toluene
260
260
130
130
Xylene
870
870
435
435
p-Dichlorobenzene
240
240
120
120
Ethylbenzene
3800
3800
1900
1900
Styrene
220
220
110
110
Tetradecane *3
330
330
165
165
Formaldehyde
100
100
50
50
Acetaldehyde
48
48
24
24
*1: The criteria regulate not the indoor concentration but the emission rate from product determinedbased on this document.
*2: Since a Desktop PC is usually used with a Display, each value was set to 1/2 of that of the
All-in-One PC.
*3: Optional target substance6

Measurement method of chemical emission rate。
This measurement method is provided for the PC based on ISO/IEC 28360.
6.1 Environmental chamber
6.1.1 Specifications
The environmental chamber shall meet the following requirements:a) The chamber shall have an air supply opening to let in controlled air and a vent to exhaust the
air from the chamber and the run parameters (airflow volume, temperature, and humidity)
shall be controllable.
b) The walls, ceiling, floor, and mount of the chamber shall be made of glass or stainless steel.
c) The use of packing materials to fill up the through-hole as in item d) below shall beminimized.
d) The air quality in the chamber shall be kept homogenized as much as possible. Air leakage
shall be minimized except for that through the air supply opening and the vent, and throughthrough-holes if prepared for wiring the EUT control, power supply, and censor cables, andsampling VOCs and aldehydes.
e) The chamber size is recommended to satisfy the following formula:0.01 < VP/VK < 0.25
VP: EUT volume (*1)
VK: Chamber volume(*1) The EUT volume is calculated as a rectangular of the maximum outside dimensions under
the installation conditions of the EUT at measurement as specified in 6.2.2 b).
6.1.2 Air conditioning
The chamber shall be set to and controlled to the following conditions:Operating temperature: 23ºC ±2ºC
Operating relative humidity: 50%±5%
Chamber air exchange rate: 0.5 or l ACH (Check the air exchange rate periodically. Monitor
the volume and the velocity of the airflow supplied into thechamber during measurement.)

86.1.3 Background concentration
The background concentrations in the chamber shall be low enough not to affect the emission
rate determination.
6.2 Determination methods
6.2.1 Preparation
EUT:
Must use the equipment in the unopened, packaging with shipment.
Temperature and humidity record:
Record temperature and humidity in the chamber during measurement
Temperature and humidity measuring point:
Perform the determination either near the vent of or in the chamber, assuming that the
air quality is kept homogenized. Avoid the proximity of the air supply opening.
6.2.2 Determination of chemical emission
Collect samples at each of the following experimental steps. Quantify the substances tocalculate the emission rate of each chemical substance by the formula described later.
a) Background determination
Collect samples in the initial unloaded condition in the chamber (prior to the installation of
the EUT).
b) Installation of EUT and operating status· Bring in and place EUT at the center of the chamber. Handle accessories, if any, as follows:- Desktop PC (*2):
With keyboard and mouse but no display- All-in-One PC (*2):
With keyboard and mouse- Laptop PC (*2):
Without mouse- Display:
Without PC- Tablet Device:
Without cradle(*2) Thin clients can be measured as original models with built-in hard disk, if theycannot function alone.
· For measurement, switch on the EUT. The OS is booted and the desktop screen is displayed(with icons displayed on the screen) to allow application run.
· All the power-saving mode settings in the Power Options Properties dialog box shall be set
to OFF as shown in Fig. 1. Settings for "Battery power" in Laptop PCs do not have to bechanged as they are measured with a power source other than battery power. If the device
has the manufacturer’s own power-saving software installed, keep the above settings on.

9

＜Windows 7＞＜Windows 8＞

Fig. 1 Settings of Power Option Properties (Laptop PC)
Source: Microsoft CorporationThe display screen shall be set to the maximum brightness.
For a Laptop PC or a folding Tablet Device, the display shall be open 90 degrees or
more.

c) Sampling timing
The target substances shall be collected in the chamber at the following timings after
10

EUT is installed in the chamber and put into operation.
Table 3 Sampling timing
Air exchange
rate
0.5 times/h
1 times/h

Sampling timing
6 h later
3 h laterd) Quantification of substance· Analysis of aldehydes
Dissolve and separate DNPH derivatives of carbonyl compounds in the DNPH cartridge byusing acetonitrile and analyze them by using a high performance liquid chromatograph. The
formaldehyde analysis method shall be as specified in ISO16000-3.
· Analysis of VOCs
Attach a Tenax tube to a thermal desorption equipment. Separate VOCs by heating andanalyze them by using a gas chromatograph mass spectrometer. The VOCs analysis method
shall be based on ISO16017-1.
e) Calculation of emission rate
(CB-CB0) × nB × VKSERUB =uCB:

Concentration of each component (μg/m3)

CB0:

Background concentration of each component (μg/m3)

SERUB: Emission rate of each component [μg/(h·unit)]nB:

Air exchange rate (h-1)

VK :Chamber volume (m3)u:Number of PCs installed (units)

11Commentary

7

7.1 Relationship between concentrations in classroom and emission rates
7.1.1 Predicted maximum concentration
The maximum probable concentration, when the emission rates from PCs are constant and theclassroom volume and ventilation rate are set, is calculated as the predicted maximum
concentration.
When the room volume is V (m3), the ventilation rate is n (h-1), the emission rate of a certain
substance from one PC per hour is SERUB [μg/(h/unit)], and the number of PCs installed is u (unit),
the average concentration Ct (μg/m3) of the substance in the room environment after t hour can be
expressed by Formula (1) and its temporal changes can be profiled as in Fig. 2.
Emission rate per hour (SERUB)[μg/(h/unit)] × Number of PCs installed (u) (unit) × t (h)3Ct (μg/m ) =Room volume (V) (m3) + Ventilation rate (n) (h-1) × Room volume (V) (m3) × t (h)SERUB × u
=

t
×

(1)
1+n×t

Concentration (μg/m3)

V

0

5

10

15

20

25

30

Time (h)Fig. 2 Temporal changes of the average concentration in the room atmosphere
If the emission rate is assumed not to change with the passage of time, therefore, the predictedmaximum concentration Cmx (μg/m3) of each component in the seven substances can be calculated
by using Formula (2).
Emission rate per PC SERUB [μg/(h/units)]×Number of PCs installed u (units)

Predicted maximum
concentration Cmx (μg/m3) =(2)
Room volume V (m3) × Ventilation rate n (h-1)
127.1.2 Installation condition to determine the predicted maximum concentration
The room volume, the ventilation rate and the number of PCs installed are necessary to convert
into the density of each room like PC classroom, an office and a house. It is a PC classroom of theschools that an atmosphere concentration becomes greatest by object materials emitting from PCs.
If data is requested from a school or related party, the calculation of the predicted maximum
concentration by using Formula (2) in the PC classroom used the following conditions.
Room volume: 180 m3 (based on the Standards for School Environment and Health)
Ventilation rate: 2.2 times/h(based on the Standards for School Environment and Health)Number of PCs installed: 40 units (one PC per student)

The above conditions are determined by referring to “[Revised version] Standards for School
Environment and Health.” For example, the ventilation rate within a room is defined as follows:
Kindergarten/elementary school: 2.2 times/h or more
Junior high school: 3.2 times/h or more
Senior high school, etc.: 4.4 times/h or more
[Revised version] School Environment and Health Control Manual “Chapter 2 Standards for
School Environment and Health Section 1”（http://www.mext.go.jp/a_menu/kenko/hoken/1292482.htm）
7.1.3 Examples of calculation
Here are examples of calculating the predicted maximum concentration in a room based on thecriteria by using Formula (2)a) Predicted maximum concentration of formaldehyde in a PC classroom
When 40 desktop PCs and 40 displays are installed in a classroom of 180 m3, the predictedmaximum concentration of formaldehyde is as in Fig. 3.

Fig. 3 Calculation of the predicted maximum concentration of formaldehyde in a PC classroom(Desktop PC and Display)b) Predicted maximum concentration when the ventilation rate is changed
When 40 Desktop PCs and 40 displays are installed in a classroom of 180 m3 and the ventilation13

rate is changed, the predicted maximum concentration is as shown in Table 4.
Table 4 Predicted maximum concentration when the ventilation rate is changed[Unit: μg/m3]
MHLW Indoor
Ventilation rate (times/h)
Substance
concentration
2.2
3.2
4.4
criteria
Toluene
260
26.3
18.1
13.1
Xylene
870
87.9
60.4
43.9
p-Dichlorobenzene
240
24.2
16.7
12.1
Ethylbenzene
3800
383.8
263.9
191.9
Styrene
220
22.2
15.3
11.1
Tetradecane *1
330
33.3
22.9
16.7
Formaldehyde
100
10.1
6.9
5.1
Acetaldehyde
48
4.8
3.3
2.4
*1: Optional target substancec) Predicted maximum concentration when the number of PCs and displays installed is changed
When the number of PCs and displays installed in a classroom of 180 m3 is changed, the predictedmaximum concentration is as shown in Table 5. (Ventilation rate: 2.2 times/h)
Table 5 Predicted maximum concentration when the number of PCs installed is changed[Unit: μg/m3]
MHLW Indoor
Number of PCs and displays installed (units)
Substance
concentration
20
30
40
criteria
Toluene
260
13.1
19.7
26.3
Xylene
870
43.9
65.9
87.9
p-Dichlorobenzene
240
12.1
18.2
24.2
Ethylbenzene
3800
191.9
287.9
383.8
Styrene
220
11.1
16.7
22.2
Tetradecane *1
330
16.7
25.0
33.3
Formaldehyde
100
5.1
7.6
10.1
Acetaldehyde
48
2.4
3.6
4.8
*1: Optional target substanced) Predicted maximum concentration when the room size is changed
When 40 PCs and 40 displays are installed in classrooms of different sizes, the predictedmaximum concentration is as shown in Table 6. (Ventilation rate: 2.2 times/h)
Table 6 Predicted maximum concentration when the room volume is changed[Unit: μg/m3]
MHLW Indoor
Classroom volume (m3)
Substance
concentration
180
250
320
criteria
Toluene
260
26.3
18.9
14.8
Xylene
870
87.9
63.3
49.4
p-Dichlorobenzene
240
24.2
17.5
13.6
Ethylbenzene
3800
383.8
276.4
215.9
Styrene
220
22.2
16.0
12.5
Tetradecane *1
330
33.3
24.0
18.8
Formaldehyde
100
10.1
7.3
5.7
Acetaldehyde
48
4.8
3.5
2.7
14

*1: Optional target substancee) Predicted maximum concentration in a six-mat room of a house
When a Desktop PC and a Display are installed in a six-mat room (26m3) of a house as an exampleof PC use at home, the predicted maximum concentration in the room is as shown in Table 7.
(According to the revised Building Standard Law, the ventilation rate was set to 0.5 times/h.)
Table 7 Predicted maximum concentration in a six-mat room of a house[Unit: μg/m3]
Substance
MHLW Indoor concentration
Predicted maximum
criteria
concentration
Toluene260
20.0
Xylene870
66.9
p-Dichlorobenzene
240
18.5
Ethylbenzene
3800
292.3
Styrene220
16.9
Tetradecane *1
330
25.4
Formaldehyde
100
7.7
Acetaldehyde
48
3.7*1: Optional target substanceThe concentrations are based on the assumption of no emission from building materials or furniture.
They are indexes indicating how much emission from the PC will contribute to the concentrations of
the seven substances in a house atmosphere.
7.2 Emission behaviors of VOCs and aldehydes from PC
7.2.1 Deterioration with time of representative emission rates after unpacking
Fig. 4 shows example of deterioration with time of emission rates after unpacking new PC is put
into operation.

Emission rate（mg/(h・unit)）

TolueneStyreneEthylbenzene
Formaldehyde

XyleneAcetaldehyde

1 Day

0

10

20

Time (h)

30

40

50

Fig. 4 Deterioration with time of VOCs and aldehydes emission rates from new PC(Desktop PC and Display)
15

Emission rates from a new PC temporarily increase after the power-on and reach the maximum
values within a few hours, and then decrease with time. (*3)
*3: Measurement data from companies show the similar tendency of attenuation as in Fig. 4, but
the emission rate differs from the products and substances. Fig. 4 shows no values on thevertical axis because the graphs are presented only to show the behaviors and are not based on
typical PC values.
7.2.2 Deterioration with time of representative emission rates
Fig. 5 shows the results of the measurement of the same PC used in 7.2.1. PC was measured
for 10 days and powered-off for 12 days, and then measured again.

Ethylbenzene
Formaldehyde

Emission rate (mg/(h・unit))

TolueneStyreneXyleneAcetaldehyde

PC powered-off (12days)

0

5

10

15

20

Time (Day)

25

30

35

Fig. 5 Deterioration with time of emission rates prior PC powered-off and after PC powered-on
again (Desktop PC and Display)
Once the initial emissions are finished, VOCs and aldehydes emissions from the PC remain loweven when the PC is powered-on again, unlike from a new PC.

16

7.3 Main sources of VOCs and units of high emission rates
7.3.1 Main sources of VOC
Table 8 lists the officially announced main sources of substances.

Substance
Formaldehyde

Table 8 Main sources
SourcePolyacetal resin (POM)

Phenol resin

Toluene and xylene

Ethylbenzene
StyreneUrea resin
Melamine resin
Synthetic resin raw material,
plasticizer raw material (phthalicacids), and coating material solvent
Synthetic resin raw material andstyrene raw material
Styrene resin, SBR rubber, polyester,AS resin, and ABS resin raw material
MS resin

Acetaldehyde
p-Dichlorobenzene

Use
Switches, electronic parts, gears,
cams, keyboard key switches,
display swivels, and othermechanical components
Adhesives and plastic coating
PC boards for power supply
Electrical parts and high-grade
coating

Electromechanical parts, car parts,
office machines, etc.
Electrical and electronic parts, andoffice machine parts
Adhesives
Generally not used for electronicequipment

7.3.2 Units of high emissions based on measurement results(1) Desktop PC
Substances with high emissions on the product level were measured for each unit. Table 9
gives some of the results. This measurement was conducted at a temperature higher than theoperating temperature because its purpose was the relative comparison of emission rates.
Table 9 Emission rate of each unit
Product (1)Product (2)Unit
Tempe Toluen Xylen Styre
Tempe Tolu Xylen Styren

CabinetKeyboard with mouse
FDD+HDD+CD-ROM
Cable (internal andexternal
Motherboard
Power-supply unit
Gas sampling method

rature
ºC
40
40
50
40-50

e

e

ne

○
○
○
○

○
○
○
○

○
○
○
○

75
○
○
△
80
×
×
○
A specimen is put in a Tedlar bag
and dry air is injected for a total of
10L with the specimen (14L if
with the cabinet). After 2-hour
heating by Drying Oven DX400,
air is sampled from the Tedlar bag.

rature
ºC
50
50
50
50

ene

e

○
○
○
-

△
○
○
-

○
○
○
-

50
○
○
○
50
○
○
○
A specimen is put in a resin bag.
After 30-minute heating at 50ºC
in a high-purity nitrogen gas
current, air is sampled from thebag.

(○: Several 10s μg or less/unit △: About 100 μg/unit ×: About 500 μg/unit)

17e(a) On the product level, toluene and xylene are emitted. The analysis of each unit showed highemissions from the power supply and motherboard in Product (1). Product (2), however, did
not show this tendency possibly because the heating temperature was lower than that of
Product (1). In addition, xylene emission from the cabinet was high probably because of thecoating. This emission from the cabinet of Product (1) was extremely small despite its
coating.
(b) Although such styrene materials as PS and ABS are used popularly as PC cabinet materials,
the emissions of ethylbenzene, styrene, p-dichlorobenzene, and acetaldehyde were smallenough to ignore possibly because the cabinet temperature was comparatively low.
Since a large amount of styrene was detected from a specific desktop PC (other than Product(1) and (2)), however, each unit was analyzed. This analysis identified the Styrofoam shock
absorber, power supply, and cable as the sources. By further analysis, styrene from the
Styrofoam was found to be contaminating the power supply and cable.
(c) Although the emission of formaldehyde was concerned because phenol boards are used forthe power supply and FDD, and several grams of polyacetal resin (POM) are used for the
optical disk and FDD, the emission was slight. Although not verified by unit evaluation, theemission may be from the PC board in the power supply that has a large area and generates
heat.
(2) LCD display
On the product level, toluene is strongly emitted from some products and formaldehyde isalso emitted. Although not verified by unit measurement, the emission may be from the power
supply (PC board, etc.).
(3) Laptop PC
Compared with other PCs, the emission of every substance is low, and is even lower than thelimit of measurement. The emission rate depends on the amount and temperature of material
and emission from inside the product, but increases as the temperature becomes higher. Unlike
other PCs, Laptop PC has such advantages that the ventilation efficiency by fan is low and atightly sealed AC adapter and optical disk are used. By unit analysis for reference, emissions oftoluene, xylene, and ethylbenzene from the AC adapter and a slight emission of xylene from thecabinet were detected.
7.4 For a safe and comfortable environment
To realize a safer and more comfortable environment, it is recommended that PCs are used inconsideration of their characteristics given in Section 7.2. For example,
 Unpack and operate PCs for a while in a well-ventilated place prior to installation
 Keep the room well ventilated at the unpacking and at the beginning of PC operation.

18

Annex 1
VOC Classification

The classification method regulated by the World Health Organization (WHO) is being generally
used at present, and that is classified in the boiling point as shown in Table 10 though there is nointernational unified classification of VOC.
Table 10 VOC classifications by the WHO
Boiling point
Classified nameExamples of VOC and boiling point
range
<50ºC
VVOC: Very Volatile Organic Compound
Methane (-161ºC)
Formaldehyde (-21ºC)
Methyl mercaptan (6ºC)
Acetaldehyde (20ºC)
Dichloromethane (40ºC)
50ºC =<<260ºC

VOC: Volatile Organic Compound

260ºC =<
< 400ºC

SVOC:Semi Volatile Organic Compound

400ºC =<

POM:Particulate Organic Matter

Acetic ether (77ºC)
Ethanol (78ºC)
Benzene (80ºC)
Methyl ethyl ketone (80ºC)
Toluene (110ºC)
Trichloroethane (113ºC)
Ethylbenzene (136ºC)
Xylene (140ºC)
Styrene (145ºC)
p-Dichlorobenzene (174ºC)
Limonene (178ºC)
L- nicotine (247ºC)
Tetradecane (253.5ºC)

Chlorpyrifos (290ºC)
Dibuthylphthalate (340ºC)
Bis(2-ethylhexyl)phthalate (384ºC)
Dioctyl phthalate (390ºC)

PCB
Benzopyrene
NOTE: The underlined substances are covered by this specification. Its application to tetradecane is optional.

19Annex 2
MHLW Indoor concentration criteria
Abstract from MHLW press release “Interim Report by the Committee on Sick House Syndrome(Indoor Air Pollution) - Summary on the discussions at the 8th and 9th meetings” at the website of
the Ministry of Health, Labor and Welfare, on Feb. 8, 2002
(http://www.mhlw.go.jp/houdou/2002/02/h0208-3.html)
Table 11 The chemical substances of which MHLW sets the indoor concentration criteria#

Volatile Organic
CompoundIndoor concentration
criteria

Toxicity Index

1

Formaldehyde

100 μg/m3 (0.08 ppm)

Nose, throat irritation inhuman inhalation exposure

2

Acetaldehyde

48 μg/m3 (0.03 ppm)

Influence on nasal olfactory
epithelium in rat respiratory
exposure

3

Toluene260 μg/m3 (0.07 ppm)

4

Xylene870 μg/m3 (0.20 ppm)

5

p-Dichlorobenzene

240 μg/m3 (0.04 ppm)

6Ethylbenzene

3800 μg/m3 (0.88 ppm)

7

Styrene

220 μg/m3 (0.05 ppm)

Chlorpyrifos

1 μg/m3 (0.07 ppb)
For child:
0.1 μg/m3 (0.007 ppb)

8

3

9

Dibuthylphthalate

220 μg/m (0.02 ppm)

10

Tetradecane

330 μg/m3 (0.04 ppm)

11

Bis(2-ethylhexyl)phthalate

120 μg/m3 (7.6 ppb)

12

Diazinon

0.29 μg/m3 (0.02 ppb)

13

Fenobucarb

33 μg/m3 (3.8 ppb)

Total
volatileorganic compound(TVOC)

Tentative: 400 µg/m3(1000 µg/m3 in new
construction)

Influence on neurobehavioral
function and reproductive
developmentinhuman
inhalation exposure
Influence on central nervous
system development of thenewborn in pregnancy rat
inhalation exposure
Influence on liver, kidney,
etc. in beagle oral exposure
Influence on liver and kidney
in mouse and rat inhalation
exposure
Influence on brain and liver in
rat inhalation exposure
Neurodevelopmental
influence on the newborn andmorphological influence on
the brains of newborn babies
in mother rat oral exposure
Influencesuchasconstitutional abnormality on
the genitals of the newborn inmother rat oral exposure
Influence of C8-C16 mixture
on liver in rat oral exposure
Patho-histological influenceon testicular in rat oral
exposure
Influence on plasma anderythrocytecholinesterase
activity in rat inhalation
exposure
Influence on cholinesterase
activity in rat oral exposure
As
low
as
rationallyachievable range based on the
results of the domestic indoor
VOC fact-finding

General Use
Urea, melamine, andphenolpolymers,
adhesives,andantiseptics
Adhesives, antiseptics,
andchemicalsforphotographic
development
Adhesives for interiormaterials, solvents anddiluents for paints
Adhesives for interiormaterials, solvents anddiluents for paints
Insecticides for clothing
and toilet perfumes
Adhesives for interiormaterials, solvents anddiluents for coatings
Styrene polymers

Termite exterminators
Paints,pigments,
adhesives,
processing
agents and plasticizer for
vinyl chloride product
Kerosene and paintsolvents
Plasticizers

Insecticides

Termite exterminators

The criteria of the above-mentioned substances are set based on the toxicity caused by short-term
exposure for formaldehyde, and by long-term exposure for other substances respectively. The
provisional target value of total volatile organic compound (TVOC) is set as low as rationallyachievable range based on the results of a fact-finding of houses in Japan, and is used as an index toindicate the indoor air quality, independently of the criteria of each substance.
20

- All rights reserved VOC Emission Rate Specification for Personal Computers and Tablet Devices(Ver. 1)
Date of issue:
January 2014
Edited and issued by: PC Environment Committee,
Personal Computers Business Committee,
Tablet Devices Environment Committee,
Tablet Devices Business Committee,
Japan Electronics and Information Technology Industries Association