Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Association

APPENDIXtoGPS pilot study report
Name: Styrene

Showa Highpolymer Co., Ltd.

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Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Association1.

Chemical substance selected and the reasons for selection .............................. 3

2.

Selected uses ........................................................................................................... 33.

Physicochemical description ................................................................................. 3

4.

Exposure to workers ............................................................................................... 4

5.

Exposure to consumers .......................................................................................... 4

6.

Environmental assessment .................................................................................... 67.

Conclusion ............................................................................................................... 7

8.

References ............................................................................................................... 72Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Association

ECETOC TARGETED RISK ASSESSMENT MODEL, Supplement

ECETOC TRA Filefor Styrene

1. Chemical substance selected and the reasons for selection
StyreneThere is public concern.
The substance has been assigned to Group 2B (possible carcinogenic) in theevaluation of carcinogenicity carried out by IARC.
There is a high risk of exposure because styrene is manufactured in large quantities(more than 1000 tons annually) and consumed in large quantities and has therefore
been designated as a high production volume (HPV) chemical by the OECD.

2. Selected uses
Unsaturated polyester resins used as flooring materials (lining) are liquid resins
containing styrene (25 w/w%) as a diluting dispersant and monomer.
Exposure to workers was evaluated during the production of unsaturated polyester
resins. The exposure to consumers was also evaluated, based on the assumptionthat consumers would only come in contact with styrene floors after their construction
had been completed.
Therefore, SU12 (Manufacture of plastics products) was selected as the Sector ofUse.

3. Physicochemical description
Application of a Haz-Map3

Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Association

4. Exposure to workers
Styrene is added for the purpose of dilution and dispersion during the manufacturing
process, after polymerization.
Therefore, PROC5 (blending and denaturation in the batch production of drugs) wasselected as the process category.
During the manufacturing process, it is necessary for the workers to operate for 4 hours
or more per day in an indoor space provided with an adequate ventilation system,
wearing respiratory protective devices that are at least 95% effective.
Rationales:
Reference values for inhalation are as follows;
NOAEL: 94 mg/m3 (*3: US EPA, IRIS Inhalation RfC Summary, 100-42-5_I.B.1.)
UF (uncertainty factor) = 30 (*3)
Thus, the UL (tolerable upper intake level) = NOAEL/UF = 94 mg/m3/30 = 3.1 mg/m3
Reference values for dermal application are as follows;
RfC＝1mg/m3 (*3)
RfC(workers ) =RfC×24hrs./8hrs.×7days/5days)＝ 1×24/8×7/5＝4.2 mg/m3
94 mg/m3 / 70 kg ×20 m3/day / 30 = 0.9 mg/kg/day
Based on the above data, the following results were obtained;

RCRInhalation = 0.35
RCRDermal = 0.076
RCRTotal = 0.25.
Therefore, no serious effects on the health of workers were predicted.

5. Exposure to consumers
Styrene is used as a top-coating material on floors that are fabricated into multilayer forcorrosion-proofing and waterproofing purposes.

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2010.01.22 Japan Chemical Industry Association
Therefore, PC_10 (plasters used for building and construction preparation) was
selected as the product category.
The amount (weight) of use per unit area totals about 50 g if it is assumed that the area
affecting each person is 30 cm square and the layer of paint applied is 500 μm thick.
Although it is not expected that people will walk on this flooring material in bare feet,the lower part of body was selected for consideration for reasons of convenience. The
possible case of fingers touching the floor was considered as oral administration.
Rationales
Reference values for inhalation concerning the exposure to consumers are as follows;
Default minute volume of a worker: MVho = 10 m3/day (*3)
Default minute volume of a consumer engaged in daily activities: MVh = 20 m3/day (*3)
NOAEL (consumers)= NOAEL (workers) × MVho/MVh × 5 days/7 days
= 94 × 10/20 × 5/7 = 34 mg/m3

UF = 30 (*3)
UL = NOAEL /UF = 34 mg/m3 / 30 = 1.1 mg/m3
Reference value for oral exposure to consumers is 0.2 mg/kg/day, based on RfD (*4).
Reference value for dermal exposure to consumers is estimated at 0.2 mg/kg/day (thesame as for oral exposure).
Reference value for the worst-case exposure to consumers is estimated at 0.02
mg/kg/day, assuming that this is 1/10 of the dermal exposure.
Based on the above data:

RCRInhalation = 0.025
RCRDermal = 0.073
RCRTotal = 0.78
These values apply to the conditions described by Scenario-3 (product ingredientfraction by weight = 0.00001 = 10 ppm).
The above values indicate that there are no serious effects on consumers, provided
that the residual concentration of styrene on the floor is 10 ppm or less (in an5

Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Associationequilibrium state in which styrene has been fully polymerized and/or has evaporated
during hardening and drying after the paint has been applied).

6. Environmental assessment
ERC2 was selected as the most appropriate ERC category because this is thecategory used to evaluate the environment in which denaturation of a formulation isperformed in a number of manufacturing plants.
Rationales
Values were extracted from the EU RAR (Vol. 27-2002) (*4) and processed using themethod shown in the part B of the ECHA Information Requirement and ChemicalSafety Assessment (ver. 1.1).
Microorganisms in STPs: 5 mg/L (*4: 3.2.1.2.3 PNEC in microorganisms)
Freshwater aquatic: 0.04 mg/L (*4: 3.2.1.2.1 PNEC in water)
Freshwater sediments: 0.34 mg/kg (*4: 3.2.1.2.2 PNEC for sediment organisms)
Marine water: No data available
Marine sediments: No data available
Terrestrial compartments: 0.255 mg/kg (*4: 3.2.3 PNEC in terrestrial compartments)
Human (via the environment): not considered
Based on the above data,
RCR in STPs = 0.077
RCR for local freshwater = 0.97
RCR for local freshwater sediments = 0.98
RCR for local terrestrial environments = 0.000074
These values apply to Description-6 (tonnage = 90).
In this simulation, no effect on the environment is predicted until production exceeds 90tons.
However, as things stand at present, there seems to be no need to predict risks, even if

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Appendix to GPS Pilot Study Report
2010.01.22 Japan Chemical Industry Association
annual production exceeds 90 tons, provided that all wastewater is fully controlled byadequate effluent treatment facilities.

7. Conclusion
In the risk characterization carried out using ECETOC-TRA, no issues arose regarding
the present status of the work environment or the exposure to workers.

Variousinvestigations were also carried out into the exposure to consumers and possible
effects on the environment, examining a variety of model cases and conditions.
It was found that the various risks could be adequately addressed by the appropriate
selection of facilities and protective devices.
It is concluded that there is no need for market restriction or the qualification andtraining of workers and further education measures for consumers, provided that risk
assessment reports can be disclosed and distributed to the public, together with theMSDS, as necessary.

8. References(*1).

Initial Risk Evaluation of Chemical Substances: Styrene.

National Institute ofTechnology and Evaluation, Japan, August 2007(*2)

Integrated Risk Information System List of IRIS Substances: Styrene(*3)

European Union Risk Assessment Report, Styrene. Part. 1-environment, Final
2002, UK(*4)

European Union Risk Assessment Report, Styrene. Draft edition, June 2008, UK(*5)

Risk Assessment Report on Styrene. Scientific Committee on Health andEnvironmental Risks, May 2006(*6)

Annex XV Transitional Dossier, Styrene UK Competent Authority, November
2008

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