Industry Specifications

CEPN

CEPN Priority Chemical Substances and MRSL: A Response Guide for the Electronics Manufacturing Industry

 

Cleaning agents, degreasers, and other solvents used in the electronics manufacturing process may pose health risks to workers, such as carcinogenicity, reproductive toxicity, and neurotoxicity. The Clean Electronics Production Network (CEPN) has therefore established a list of priority chemical substances as an important reference for the Electronics Manufacturing Restricted Substances List (MRSL), promoting the phased-out or safer alternatives for high-risk process chemicals.

As of 2026, CEPN has announced three rounds of priority chemical substances, totaling 35 substances. Although the related requirements are not government-mandated regulations, they may still be incorporated into supplier management, customer audits, and chemical management processes by brands. Manufacturers, brands, and chemical suppliers should grasp the usage situation within the factory, supplier composition information, and feasibility of alternatives early to reduce worker exposure and supply chain transition risks.

Introduction: New Trends in the Green Transformation of the Electronics Industry

As the electronics manufacturing industry advances toward sustainable development, protecting the health of frontline workers has become the most critical issue for brands and supply chains alike. A key international vision driving this green transformation is the implementation of the "Toward Zero Exposure" initiative, which aims to achieve zero worker exposure to toxic chemicals in manufacturing processes. To realize this vision, the Clean Electronics Production Network (CEPN) brings together international electronics brands, suppliers, labor and environmental organizations, research institutions, and public sector bodies. Some brands have also committed through the TZE program to eliminate and substitute priority chemical substances and disclose their progress. For companies seeking to enter major international markets, CEPN priority chemical substances and related management requirements are increasingly becoming an important reference used by some international brands to evaluate supply chain process chemical management capabilities. Quick Introduction to CEPN

Nature

An industry cooperation initiative and supply chain management framework; not a government-mandated regulation.

Scope of Management

Process chemicals used in electronics manufacturing.

Management Objective

Prioritize the elimination or substitution of highly hazardous substances with safer alternatives.

Key Corporate Actions

Chemical inventorying, data disclosure, substitution, exposure control, and progress verification.

What Is CEPN? Definition and Core Objectives

The Clean Electronics Production Network (CEPN) is a transnational/regional organization with more than 20 stakeholders — including brand companies, supply chain enterprises, NGOs, and government agencies — that jointly participate in its work. Its core function is to identify high-risk chemicals in electronics manufacturing processes that should be prioritized for elimination or substitution, and to compile them into a Manufacturing Restricted Substances List (MRSL). The current focus is on solvents in manufacturing cleaning products, as this is the area of highest worker exposure risk. CEPN has established three rounds of priority chemical substance lists, encompassing 35 substances in total. The screening process for priority chemical substances is as follows:

CEPN Screening Process for Priority Chemical Substances
Image：CEPN Screening Process for Priority Chemical Substances

Priority Chemical Substances List

Round 1: Details on 9 Chemical Substances (Published: December 2019)

Substance Name CAS No. Reference Concentration Limit Common Uses Primary Hazards
1-Bromopropane 106-94-5 <0.1% Cleaning of metals, plastics, electronic components, and optical parts; also potentially used in adhesive sprays. May cause nervous system damage, carcinogenicity, reproductive toxicity, and developmental effects.
Benzene 71-43-2 <0.1% Solvent in adhesives, sealants, paints, coatings, and inks used in electronics final assembly. Possibly carcinogenic; causes nervous system and bone marrow damage.
Dichloromethane (Methylene Chloride) 75-09-2 <0.1% Paint remover; degreasing agent in the electronics manufacturing industry. Animal studies indicate possible liver and lung carcinogenicity; may affect the central nervous system.
Methanol 67-56-1 <1.0% Alcohol-based solvent used in cleaning products or equipment. Absorbed through skin, eyes, lungs, and digestive system; may cause blindness, kidney failure, and other serious health effects.
n-Hexane 110-54-3 <0.1% Degreasing and cleaning solvent; used for mobile screen and PCB cleaning, and flux residue removal. May affect the central nervous system and irritate the skin and respiratory tract; animal studies indicate possible male reproductive toxicity.
N-Methyl-Pyrrolidone (NMP) 872-50-4 <0.1% Cleaning of printed circuit boards and semiconductor components; also used as a photoresist diluent. May cause reproductive and developmental toxicity; may also affect the kidneys, liver, and nervous system.
Tetrachloroethylene 127-18-4 <0.1% Metal surface preparation and electronics equipment cleaning. Possibly carcinogenic; causes liver damage and irritates the eyes, skin, and respiratory system.
Toluene 108-88-3 <0.1% Cleaning solvent; solvent in adhesives, paints, coatings, and inks. May cause central nervous system and reproductive system damage and increase the risk of miscarriage.
Trichloroethylene 79-01-6 <0.1% Vapor degreasing; semiconductor ingot and wafer cleaning. Known carcinogen; may cause liver damage and developmental effects.
Note: N-Methyl-Pyrrolidone (NMP) is subject to a conditional exemption when used for photoresist stripping.

Round 2: Details on 16 Chemical Substances (Published: June 2023)

Substance Name CAS No. Reference Concentration Limit Common Uses Primary Hazards
Cumene 98-82-8 <0.1% Solvent or diluent in lacquers, coatings, adhesives, and inks; also used in cleaning processes. Suspected carcinogen; may cause respiratory tract irritation.
1,2-Dichloroethane 107-06-2 <0.1% Solvent for removing grease, resins, adhesives, and grime. Possibly carcinogenic; inhalation is toxic and may cause respiratory tract irritation.
1,2-Diethylene glycol dimethyl ether 111-96-6 <0.1% Used in the coatings industry, semiconductor wafer photolithography, and in adhesives and sealants. May damage fertility or harm the unborn child.
Dimethylformamide (DMF) 68-12-2 <0.1% Solvent for electronics component production; solvent for epoxy resin catalysts in PCB lamination processes. Possibly carcinogenic; may also damage fertility or harm the unborn child.
2-Ethoxyethanol 110-80-5 <0.1% Industrial solvent for printing inks, dyes, and coatings. May damage fertility or harm the unborn child; inhalation is toxic.
2-Ethoxyethyl acetate 111-15-9 <0.1% Solvent for metal degreasing, semiconductor manufacturing, and applications involving cellulose, resins, and coatings. May damage fertility or harm the unborn child.
Ethylbenzene 100-41-4 <0.1% Solvent or diluent in lacquers, coatings, adhesives, and inks; possibly used in cleaning and adhesive formulations. Suspected carcinogen; prolonged or repeated exposure may damage auditory organs.
2-Methoxyethanol 109-86-4 <0.1% Resin solvent in the electronics industry; also used in dyes and quick-drying lacquers. May damage fertility or harm the unborn child; may also affect the immune system and thymus.
Methyl isobutyl ketone (MIBK) 108-10-1 <0.1% Solvent for coatings, inks, primers, and adhesives in the electronics industry; also used in the semiconductor sector. Suspected carcinogen; may cause drowsiness or dizziness.
Nitromethane 75-52-5 <0.1% Solvent for coatings and inks. Suspected carcinogen; may also damage fertility or harm the unborn child.
Pentachloroethane 76-01-7 <0.1% Metal vapor degreasing and ultrasonic cold cleaning. Suspected carcinogen; prolonged or repeated exposure may cause organ damage.
1,1,1,2-Tetrachloroethane 630-20-6 <0.1% Co-solvent in degreasing processes. Suspected carcinogen; skin contact may be fatal; inhalation is toxic.
1,1,2,2-Tetrachloroethane 79-34-5 <1.0% Historically used for metal cleaning and degreasing, paint removal, and other solvent applications. Skin contact or inhalation may be fatal.
Tetrahydrofurfuryl alcohol (THFA) 97-99-4 <0.1% Solvent for oils, waxes, and resins; also used in cleaning agents and paint removers. May damage fertility or harm the unborn child.
Trichloromethane (Chloroform) 67-66-3 <0.1% Cleaning agent; solvent for rubber, wax, and resins. Suspected carcinogen and reproductive hazard; inhalation is toxic; prolonged or repeated exposure may damage the liver and kidneys.
Xylenes 1330-20-7 <0.1% Solvent for coatings, inks, primers, and adhesives in the electronics industry; also used in semiconductor manufacturing. Suspected carcinogen.

Round 3: Details on 10 Chemical Substances (Published: April 2026)

Substance Name (Chinese & English) CAS No. Reference Concentration Common Uses Main Hazards
1,1-Dichloroethane 75-34-3 <1.0% Chemical manufacturing intermediate, fumigant, and cleaning/degreasing solvent; historically used for degreasing in the electronics industry. Possibly carcinogenic.
1,1-Dichloroethylene 75-35-4 <1.0% Cleaning, degreasing, and extraction solvent. Possibly carcinogenic.
1,2-Dichloropropane 78-87-5 <0.1% Soil fumigant and chemical manufacturing; historically used as a solvent degreaser. Possibly carcinogenic.
N,N-Dimethylacetamide (DMAC) 127-19-5 <0.1% Solvent for polymers and resins; also used in fiber production, coatings, and adhesives.。 May damage fertility or harm the unborn child.
1-Ethylpyrrolidin-2-one (NEP) 2687-91-4 <0.1% Solvent, catalyst, and surfactant. May cause genetic mutations and carcinogenicity.
Hydrotreated light straight run (Petroleum) 64742-49-0 <0.1% Solvent degreaser for metal, plastic, and glass surfaces. May cause genetic mutations and carcinogenicity.
Ligroine (Petroleum naphtha) 8032-32-4 <0.1% Paint solvent, cleaning agent, and degreaser. May cause genetic mutations and carcinogenicity.
2-(2-Methoxyethoxy)ethanol (DEGME) 111-77-3 <0.1% Paints, coatings, and cleaning products. May damage fertility or harm the unborn child.
2-Methoxyethyl acetate 110-49-6 <0.1% Solvent, adhesive/sealant, and stripping agent; also used in semiconductor manufacturing. May damage fertility or harm the unborn child.
1,1,2-Trichloroethane 79-00-5 <1.0% Chemical intermediate and solvent; historically used as a solvent and degreaser in the electronics industry. Possibly carcinogenic.

Which Industries and Processes Will Be Affected?

The CEPN Priority List focuses its restrictions on "process chemicals" rather than solely on residues in finished products. The following industries should pay particular attention to the implications of specific chemicals:

CEPN Screening Process for Priority Chemical Substances
Image：CEPN Screening Process for Priority Chemical Substances

Five Key Corporate Response Strategies

In the face of stringent international regulatory and standards requirements, companies are recommended to adopt a systematic response approach:

  1. Inventory Process Chemicals： Establish a clear list of process chemicals, taking inventory of all cleaning agents, degreasers, and process aids, including product names, suppliers, locations of use, applications, annual usage volumes, and exposure scenarios.
  2. Collect and Verify Ingredient Data：Review Safety Data Sheets (SDS), full material declarations, technical data sheets, and supplier questionnaires.
  3. Screen for Hazardous Substances：Cross-reference against the CEPN Round 1 to Round 3 priority substances, categorizing items as confirmed present, possibly present, data insufficient, or no risk. Also monitor the CEPN "Watch List" to guard against future risks.
  4. Verify, Track, and Continuously Update：When SDS, material declarations, or supplier data are insufficient to complete a risk determination, supplement with ingredient evidence through third-party analytical testing. Combine this with chemical inventories, supply chain document reviews, and process risk assessments to improve the reliability of determinations.
  5. Plan Substitution Strategies：Prioritize elimination or substitution. Until substitution is complete, continue to implement engineering controls, personal protective equipment, and worker communication.

Conclusion and Testing Service Recommendations: Why Choose Professional Testing?

CEPN's "zero exposure" vision is rapidly changing the rules of the game in the electronics industry. Companies should not wait until brand auditors initiate an audit or a compliance gap is discovered before taking action. Proactive management not only protects worker health but also reduces the risk of audit findings, last-minute substitutions, supply disruptions, and reputational damage.

Through professional third-party testing, companies can bridge the gap caused by insufficient supplier SDS information and precisely identify hidden hazardous chemicals in their processes. SGS provides comprehensive testing services, conformity assessments, and training programs for CEPN Round 1 to Round 3 chemical substances, helping companies quickly align with brand customers' requirements:

  • CEPN List and Client MRSL Gap Assessment
  • SDS and Ingredient Data Review
  • High-Risk Substance Screening and Analytical Testing
  • Supply Chain Documentation and Compliance Assessment
  • Substitution and Risk Management Recommendations

Unsure whether your facility's chemicals involve CEPN priority substances? SGS can assist companies through process inventories, document reviews, and analytical verification to identify data gaps and priority improvement items. Contact us today.

*The content on this page is provided for general information and risk management reference purposes only and does not constitute legal advice or a guarantee of conformity with any specific customer requirement. CEPN and TZE content is subject to change; actual determinations should be based on the latest official documents, customer specifications, and applicable regulations.

Reference Source：

Have questions about regulations or testing?
Write them here, and a specialist will reply to you!

Contat Us

Further Reading

  1. SONY發布環境管理物質規範(SS-00259)第二十四版，新版本已在2026年六月強制生效

  2. UK REACH SVHC高關注物質候選清單新增15項物質

  3. 拆解美國PFAS「地方市場禁令趨同」與「聯邦動態申報」的雙軌路徑

  4. 《資源循環推動法》三讀通過：電子電器產業邁向全生命週期管理新時代

  5. 法國《Thierry 法案》全面上路，承襲歐盟三層級門檻力阻 PFAS 污染
Taipei
Kaohsiung
e電園
SGS RSTS Cloud

Terms of Service

Privacy

Cookies Policy

Sitemap

Site Search

SGS TW 安心資訊平台 SGS管理學院

© 2019~2026 SGS TAIWAN All Rights Reserved | Designed by SGS Taiwan WebTeam