VOC Emission Rate Specification for
Personal Computers and Tablet Devices (Ver. 2)

March 2019Japan 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.

April 2019

Issued “VOC Emission Rate Specification for Personal Computers andTablet Devices (Ver. 2).
Main revisions○ Revised concept for setting criteria.
・Conforms with the FY 2018 Revised Manual for School Environmental-Hygiene
Management○ Revised criteria for VOC emission rates
・Adjusted the criteria for xylene

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.
In 1997, the Ministry 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 (MEXT) partly revised theStandards of School Environment and Health in 2002, in which formaldehyde and VOCs (toluene,
xylene, and p-dichlorobenzene) concentrations were added to the inspection items of the air
environment to maintain 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 mademandatory for school equipment vendors to submit data about VOCs and aldehydes emission from theequipment 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 and styrene have been added) are covered by the regulation. In accordance with theenforcement of the School Health and Safety Act in 2009, the new Standards for School Environmentand 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 with the situation.
IT Product Environment Committee organized the VOC Task Force and formulated this guideline
in September 2005 to establish a standardized determination method and emission rate criteria, as wellas to enlighten the public that the PC industry is making voluntary efforts to curb VOC and aldehyde
emissions from PCs.
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 volatileorganic compounds and carbonyl compounds emissions for electronic equipment — Chamber method”
consistent with ISO/IEC 28360 was established.
Under such circumstances, JEITA established industry-wide measurement methods and emissions
criteria then issued its “VOC Guidelines for Personal Computers (Ver. 1)” in September 2005 in aneffort to more widely disseminate information about the current status of its independent initiatives
involving VOCs and aldehydes connected to personal computers. The second version of theseguidelines which contained a revised VOC measurement method that conforms with ISO/IEC 28360,
was released in 2008.
“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 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, wereadded to the range of equipment covered due to their increasing use in the classroom. The specification
was retitled "VOC Emission Rate Specification for Personal Computers and Tablet Devices (Ver. 1)."
A second version was subsequently released to reflect the March 2018 revisions to the Manual for
School Environmental-Hygiene Management as well as the changes to the indoor concentration criteria
made in January 2019.
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

JIS C 9913 Measuring method of volatile organic compounds and carbonyl compounds emissions
for electronic equipment Chamber method
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” established by
the Committee on Sick House Syndrome (Indoor Air Pollution) of the Ministry of Health, Laborand Welfare (MHLW). The criteria are not the legal requirement values, but used as a target ofindoor air quality. For more details, refer to the following URL. Annex 2 gives an abstract forreference.
（ https://www.mhlw.go.jp/content/000470188.pdf ）(4) Standards of School Environment and Health
The management criteria established by MEXT 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 suchas classrooms, there is a specification on formaldehyde and volatile organic compounds.
(5) 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 infinitesimalamounts of 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.
(6) Thin clients
Security-oriented terminal used in a business information system. It has a system configurationin which the capabilities of a client are limited to the minimal functions so that sources 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
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.
(7) 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.
(8) Predicted maximum concentration
4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 the predictedmaximum concentration.
(9) 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.
(10) 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).
(11) Emission rate
The mass of each substance [lμg/(h·unit)] emitted from the EUT per unit time.
(12) 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.
(13) 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 the chamber from theprevious measurement) may be mixed in the collected air, and may affect the measurement
results. Therefore, the background concentration shall be pre-determined, and the determined
concentration with the EUT subtracted from this background concentration shall be adopted as
the concentration of emitted substances.
(14) 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.
(15) Carbonyl compounds
Among all the compounds having a carbonyl group (C = O), aldehydes, ketones, and ketenes
are called carbonyl compounds. Those compounds in which the carbon (C) of the carbonylgroup 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＝C＝O
C＝O
R’
R’
R
Aldehyde group
Ketene group
Ketone group(16) Carbonyl compounds DNPH derivatives
The aldehydes that are derivatized with DNPH compounds. The DNPH-derivative
compounds shall be separated and analyzed in a liquid chromatograph.
(17) 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 eluant5(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 a detector.
(18) 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.
(19) 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.
(20) 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.
(21) Manual for School Environmental-Hygiene Management
A manual published by MEXT explaining the school environmental-hygiene standards in detail.
It describes the basis for selecting each inspection item and target value, how to conduct
inspections, and what follow-up steps should be taken. For more information, refer to thefollowing URL:
（http://www.mext.go.jp/a_menu/kenko/hoken/1292482.htm）

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 concentration thatcan 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 was chosen
as a model in this guideline. The specific condition is as following.


Room volume: 180 m3 from the Manual for School Environmental-Hygiene
Management)
Ventilation rate: 2.4 times/h (from the Manual for School Environmental-Hygiene
Management (Early Elementary School)
Number of PCs installed: 41 (from the Manual for School Environmental-Hygiene
Management; one PC per student)[Reference]
The room ventilation rates introduced in the Manual for School Environmental-Hygiene
Management are as follows:
Kindergarten:
At least 2.1 times/h (1 teacher + 35 students)
Early Elementary School:
At least 2.4 times/h (1 teacher + 40 students)
Late Elementary/Middle School:
At least 3.4 times/h (1 teacher + 40 students)
High School:
At least 4.6 times/h (1 teacher + 40 students)

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 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.

7

Table 2 Emission criteria (Emission rates from product)*1[Unit: μg/(h·unit)]
TabletLaptop PC
All-in-One PC Desktop PC*2
Display*2
260
260
130
130
260
200
200
100
100
200
240
240
120
120
240
3800
3800
1900
1900
3800
220
220
110
110
220
330
330
165
165
330
100
100
50
50
100
48
48
24
24
48
*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 Allin-One PC.
*3: Optional target substance

Substance
TolueneXylenep-Dichlorobenzene
Ethylbenzene
StyreneTetradecane *3
Formaldehyde
Acetaldehyde

6

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 be minimized.
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%8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.)
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 thatthe 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 to calculate
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 cartridgeby using 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)Ct (μg/m3) =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.
While the enlargement of displays have been progressing in recent years, this document assumes
that 41 units will be used within a single PC classroom. Therefore the display size is specified(displays over 30 inches in size are not covered).
Room volume: 180 m3 (from the Manual for School Environmental-Hygiene
Management)
Ventilation rate: 2.4 times/h (from the Manual for School Environmental-Hygiene
Management (Early Elementary School)
Number of PCs installed: 41 (from the Manual for School Environmental-Hygiene
Management; one PC per student)

The above conditions are determined by referring to “Standards for School Environment and
Health.” For example, the ventilation rate within a room is defined as follows:
The room ventilation rates introduced in the Manual for School Environmental-Hygiene
Management are as follows:
Kindergarten:
At least 2.1 times/h (1 teacher + 35 students)
Early Elementary School:
At least 2.4 times/h (1 teacher + 40 students)
Late Elementary/Middle School:
At least 3.4 times/h (1 teacher + 40 students)
High School:
At least 4.6 times/h (1 teacher + 40 students)

School Environment and Health Control Manual “Chapter 2 Standards for School Environmentand 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 when the ventilation rate is changed
When 41 Desktop PCs and 41 displays are installed in a classroom of 180 m3 and the ventilation
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
2.4
3.4
4.6
criteria
Toluene
260
24.7
17.4
12.9
Xylene
200
19.0
13.4
9.9
p-Dichlorobenzene
240
22.8
16.1
11.9
Ethylbenzene
3800
360.6
254.6
188.2
Styrene
220
20.9
14.7
10.9
Tetradecane *1
330
31.3
22.1
16.3
Formaldehyde
100
9.5
6.7
5.0
Acetaldehyde
48
4.6
3.2
2.4
13

*1: Optional target substanceb) 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 5.
(According to the revised Building Standard Law, the ventilation rate was set to 0.5 times/h.)
Table 5 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
Xylene200
15.4
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.
Ethylbenzene

XyleneStyreneFormaldehyde

Acetaldehyde

Emission rate（mg/(h・unit)）

Toluene

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)14

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 poweredon 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.

15

7.3 Main sources of VOCs and units of high emission rates
7.3.1 Main sources of VOC
Table 6 lists the officially announced main sources of substances.

Substance
Formaldehyde

Table 6 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 7 gives
some of the results. This measurement was conducted at a temperature higher than the operating
temperature because its purpose was the relative comparison of emission rates.
Table 7 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 withthe cabinet). After 2-hour heating
by Drying Oven DX400, air issampled 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)

16e(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 fromthe cabinet 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.

17

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 8 though there is nointernational unified classification of VOC.
Table 8 VOC classifications by the WHO
Boiling
Classified nameExamples of VOC and boiling point
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.

18

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 23th meetings” at the website of the
Ministry of Health, Labor and Welfare, on Jan. 17, 2019（https://www.mhlw.go.jp/content/000470188.pdf）
Substances for which criteria have been established
Volatile Organic
CompoundFormaldehyde

Indoor concentration

Toxicity Index

criteria

Nose, throat irritation in humaninhalation exposure
olfactory epithelium in rats as aevision100 μg/m3 (0.08 ppm)

Created on
1997.6.13

48 μg/m3 (0.03 ppm)

Created on
2002.1.22

260 μg/m3 (0.07 ppm)

Created on
2000.6.26

Influence on the nasopharyngeal
Acetaldehyde

Date of
Creation/R

result of respiratory exposure

TolueneInfluenceonfunctionandneurobehavioral
reproductive

development in human inhalation
exposure
Influence on the human central

Xylenenervous system as a result of long-

200 μg/m3 (0.05 ppm)

term occupational exposure
Ethylbenzene
Styrenep-Dichlorobenzene
Tetradecane

Revised on
2019.1.17

Influence on liver and kidney inmouse and rat inhalation exposure
Influence on brain and liver in rat
inhalation exposure
Influence on liver, kidney, etc. inbeagle oral exposure
Influence of C8-C16 mixture on
liver in rat oral exposure
Neurodevelopmental influence on

Chlorpyrifos

Created on
2000.6.26

the newborn and morphologicalinfluence on the brains of newborn

3800 μg/m3 (0.88 ppm)

Created on
2000.12.15

220 μg/m3 (0.05 ppm)

Created on
2000.12.15

240 μg/m3 (0.04 ppm)

Created on
2000.6.26

330 μg/m3 (0.04 ppm)

Created on
2001.7.5

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

Created on
2000.12.15

33 μg/m3 (3.8 ppb)

Created on
2002.1.22

0.29 μg/m3 (0.02 ppb)

Created on
2001.7.5

babies in mother rat oral exposure
Fenobucarb

Influencecholinesterase

activity in rat oral exposure
Influence

Diazinonononplasmaanderythrocyte cholinesterase activity
in rat inhalation exposure
Influence on the reproductive

Dibuthylphthalate

system or developmental toxicity

17 μg/m3 (1.5 ppb)

of rats

Created on
2000.12.15
Revised on
2019.1.17

Bis(2ethylhexyl)

Influence on the male genitalia ofphthalate

rats

19

100 μg/m3 (6.3 ppb)

Created on
2001.7.5

Revised on
2019.1.17
Total volatile organic
compound (TVOC)

As low as rationally achievable
range based on the results of theTentative: 400 µg/m3

Created on
2000.12.15

domestic indoor VOC fact-finding

Note 1: The literature often lists a vapor pressure for Bis(2-ethylhexyl) phthalate of 1.3 × 10-5 Pa (25 ℃)
to 8.6 × 10-4 Pa (20 ℃), which corresponds to a concentration range of 0.12 ppb – 8.5 ppb.
Note 2: These are the lowest values that are reasonably attainable, as determined from the results of onsite VOC surveys of indoor environments in Japan. While the tentative TVOC values can beused for comprehensive approximations of VOCs contained within the air of indoor
environments, they were not selected from a toxicological point of view, therefore someincluded substances may not have worrisome effects on health. Also, the individual VOC criteria
must be treated independently.

20

- All rights reserved VOC Emission Rate Specification for Personal Computers and Tablet Devices(Ver. 2)
Date of issue:
March 2019
Edited and issued by:
PC･Tablet Environment Committee,
PC･Tablet Business Committee,
Japan Electronics and Information Technology Industries Association