GHS hazard statements
GHS hazard statements are standardized phrases assigned to specific hazard classes and categories within the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), an international framework developed by the United Nations to communicate chemical hazards consistently across borders.[1] Adopted by the UN Economic and Social Council in 2003, the GHS aims to enhance the protection of human health and the environment while facilitating international trade by replacing diverse national systems with uniform criteria for classifying physical, health, and environmental hazards.[2] Hazard statements specifically describe the nature of these hazards in clear, concise language, appearing on product labels and in Section 2 of safety data sheets (SDSs) to alert workers, consumers, and emergency responders to potential risks.[3] Each hazard statement is assigned a unique alphanumeric code beginning with the letter "H" followed by three digits, enabling precise identification and translation into multiple languages without altering meaning.[4] The codes are structured as follows: H200–H299 for physical hazards (e.g., H226: Flammable liquid and vapour), H300–H399 for health hazards (e.g., H301: Toxic if swallowed), and H400–H421 for environmental hazards (e.g., H400: Very toxic to aquatic life).[3] These statements must be included on labels alongside pictograms, signal words ("Danger" or "Warning"), and precautionary statements, with multiple statements combined for readability when a chemical presents several hazards.[1] The system ensures that the severity of hazards is conveyed through category-specific phrasing, such as distinguishing between acute and chronic effects. The GHS, including its hazard statements, is periodically revised by the UN Sub-Committee of Experts on the GHS, with the eleventh edition published in September 2025 incorporating updates like clarified criteria for aerosols, non-animal testing methods, and new provisions for global warming potential hazards.[5] Implementation varies by country—mandatory in the European Union via the CLP Regulation since 2008 and aligned with OSHA's Hazard Communication Standard in the United States since 2012—but the core hazard statements remain harmonized to promote global consistency.[6] This standardization has significantly improved hazard communication, reducing misinterpretation of risks and supporting safer handling of the approximately 350,000 chemicals and mixtures in global commerce.[7]Fundamentals of GHS Hazard Statements
Definition and Purpose
GHS hazard statements are standardized phrases, denoted by H-codes, that describe the nature and, where appropriate, the degree of hazards associated with chemicals. These statements are assigned to specific hazard classes and categories within the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), developed by the United Nations to provide consistent hazard information. They form a core element of hazard communication, appearing on labels and in safety data sheets (SDSs) to convey risks clearly and uniformly.[8] The primary purpose of GHS hazard statements is to facilitate the global harmonization of chemical safety information, replacing disparate national systems with a single framework that enhances protection for human health and the environment. By standardizing descriptions of hazards, they enable multilingual translation and consistent application across borders, supporting workers, consumers, emergency responders, and regulators in understanding and mitigating risks. This system was adopted to address inconsistencies in existing regulations, promoting safer handling, transport, and use of chemicals while minimizing trade barriers caused by varying labeling requirements.[4] The scope of GHS hazard statements encompasses physical, health, and environmental hazards for both substances and mixtures, but excludes provisions specific to the transport of dangerous goods, which are governed separately by UN recommendations. Key benefits include reduced confusion in international commerce through uniform communication, improved emergency response via clear hazard identification, and strengthened regulatory compliance worldwide. These statements complement other GHS elements, such as precautionary statements, to provide comprehensive guidance without overlapping transport regulations.[9]Historical Development and Revisions
The development of the Globally Harmonized System (GHS) of Classification and Labelling of Chemicals originated from international efforts to standardize chemical hazard communication, initiated following Chapter 19 of Agenda 21 adopted at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in 1992.[10] This chapter emphasized the need for harmonized approaches to chemical classification and labelling to protect human health and the environment, leading to the establishment of a coordination mechanism under the Inter-Organization Programme for the Sound Management of Chemicals (IOMC), involving key organizations such as the United Nations (UN), International Labour Organization (ILO), Organisation for Economic Co-operation and Development (OECD), and Food and Agriculture Organization (FAO).[11] The first official version of the GHS was adopted by the UN in December 2002 and published in 2003 as Revision 1 (Rev. 1), which introduced the core framework for hazard statements (H-statements) to provide standardized phrases describing the nature and severity of hazards.[2] Key milestones in the GHS's evolution include its formal endorsement at the World Summit on Sustainable Development in Johannesburg in 2002, which urged global implementation, and subsequent adoptions by the ILO through its conventions on chemical safety and by the OECD in its mutual acceptance of data guidelines.[12] Mandatory implementation began around 2008 in several countries, aligning with the UN's call for widespread adoption to facilitate international trade and reduce discrepancies in national systems.[13] The system is maintained and updated biennially by the UNECE Committee of Experts on the Transport of Dangerous Goods and on the Globally Harmonized System of Classification and Labelling of Chemicals, ensuring ongoing refinement based on scientific advancements and stakeholder input.[14] Subsequent revisions have progressively expanded and clarified the GHS, particularly the hazard statement system. Rev. 3 (2009) incorporated provisions for aerosols, enhancing classification for pressurized products.[15] Rev. 7 (2017) introduced a new hazard class for desensitized explosives, addressing substances that are rendered less sensitive through additives like water or phlegmatizers.[16] Rev. 10 (2023) refined criteria for physical hazards, including updates to desensitized explosives and incorporation of non-animal test methods for health classifications.[17] The most recent, Rev. 11 (adopted in December 2024 and published in September 2025), includes clarified criteria for aerosols and pressurized liquids under physical hazards, introduction of a new hazard class for substances contributing to global warming based on global warming potential (GWP), revisions to environmental endpoints such as ozone-depleting substances, and minor adjustments to H-statements for improved clarity and consistency.[5][18] As of 2025, over 80 countries have adopted the GHS in some form, with varying degrees of alignment to specific revisions, promoting a more unified global approach to chemical safety while allowing flexibility for national priorities.[19]Coding and Organization
Code Structure
GHS hazard statements follow a standardized format consisting of a concise descriptive phrase prefixed by the letter "H" and a three-digit numeric code, such as H250 or H360, to uniquely identify each statement for reference and consistency across global implementations.[20][21] The numbering system is structured to reflect both the type of hazard and its specific classification details: codes in the H200 series denote physical hazards, H300 series indicate health hazards, and H400 series cover environmental hazards, with the initial digit (2, 3, or 4) signaling the broad hazard category.[20][22] The remaining two digits further specify the hazard class and category, where lower category numbers typically represent greater severity—for instance, category 1 hazards often carry more acute risks than category 4, influencing the phrasing and associated signal words like "Danger" for severe cases versus "Warning" for lesser ones.[20][3] Multiple hazard statements can be combined on a single label or safety data sheet when a substance or mixture exhibits several hazards, promoting efficient communication without redundancy, provided the overall label remains legible.[3] Translations of these statements into national languages are required to maintain the exact meaning and intent of the original English phrasing, ensuring uniform hazard awareness worldwide.[5] The eleventh revision of the GHS, published in 2025, introduced refinements to the code structure and phrasing, including standardized language for emerging subcategories within physical hazards such as explosives, to accommodate evolving classifications like those for serial or binary types.[5] These statements are integral to hazard communication requirements, appearing mandatorily on product labels alongside appropriate signal words ("Danger" for high-severity hazards or "Warning" for moderate ones) and corresponding GHS pictograms to visually reinforce the risks.[3][23] In safety data sheets (SDS), hazard statements are detailed in Section 2, "Hazard Identification," where they list all applicable codes and descriptions to inform users, transporters, and emergency responders comprehensively.[23][24]Categorization by Hazard Type
The Globally Harmonized System (GHS) categorizes hazard statements into three primary types—physical, health, and environmental—to systematically communicate risks associated with chemicals. This structure aligns with the inherent properties of substances and mixtures, enabling consistent classification across global supply chains. Hazard statements are grouped under these categories based on standardized criteria that evaluate the nature and severity of potential dangers, ensuring that users can quickly identify and mitigate risks.[25] Physical hazards encompass risks arising from the chemical's physical properties, such as instability, reactivity, or potential to cause physical harm through fire, explosion, or corrosion. These include dangers like flammability, where substances are assessed using metrics such as flash point (the lowest temperature at which vapors ignite) to determine ignitability under normal conditions, and corrosivity to metals, evaluated by reaction rates or mass loss in standardized tests. Reactivity hazards, including self-reactive substances or those emitting flammable gases upon contact with water, are classified based on energy release potential or thermal stability thresholds. Overall, physical hazards cover 17 distinct classes, focusing on properties that could lead to uncontrolled energy release or structural damage.[25][22] Health hazards address adverse effects on human health, either acute (immediate) or chronic (long-term), resulting from exposure via specific routes such as oral ingestion, dermal contact, or inhalation. Examples include acute toxicity, measured by lethality thresholds like LD50 (lethal dose for 50% of test subjects) or LC50 (lethal concentration), and irritation or sensitization, assessed through standardized animal or in vitro tests for skin or eye damage. Chronic effects, such as carcinogenicity or reproductive toxicity, are evaluated using epidemiological data, genotoxicity assays, or exposure duration models. These 10 classes emphasize dose-response relationships and exposure pathways to prioritize protective measures for workers and consumers.[25][22] Environmental hazards focus on detrimental impacts to ecosystems and the broader atmosphere, classifying substances based on their persistence, bioaccumulation, and toxicity to non-target organisms. Key examples include aquatic toxicity, determined by metrics like LC50 or EC50 (effective concentration causing 50% mortality or sublethal effects in fish, daphnia, or algae over defined periods), and ozone depletion potential, now expanded under the renamed "hazardous to the atmospheric system" class. The eleventh revision introduces a new category within the renamed "Hazardous to the atmospheric system" class for substances hazardous due to contributions to global warming, using Global Warming Potential (GWP) values relative to carbon dioxide to gauge climate impacts. Comprising two classes, this category highlights long-term ecological disruptions.[25][26] Across these categories, GHS aligns hazard statements with 29 total hazard classes, where severity is scaled from Category 1 (most severe, indicating highest risk levels) downward to less acute categories based on quantitative thresholds. This hierarchical approach ensures proportional communication of dangers, with Category 1 often requiring the strongest precautionary actions. The eleventh revision (2025) introduces nuances to address overlaps between physical and environmental hazards, such as clarifying classifications for pressurized substances that may contribute to atmospheric effects, promoting integrated risk assessment.[25][22]Standard GHS Hazard Statements
Physical Hazard Statements
Physical hazard statements in the Globally Harmonized System (GHS) encompass the H200–H299 series, which communicate risks arising from the physical properties of chemicals, such as the potential for explosion, fire, or violent reaction under specific conditions. These statements are integral to hazard communication on labels and safety data sheets, enabling users to anticipate and mitigate physical dangers like ignition or pressure buildup. Assigned based on rigorous classification criteria in GHS Chapter 2, they reflect the inherent reactivity or instability of substances and mixtures, determined through standardized laboratory tests that assess factors like ignition sensitivity and propagation potential. The eleventh revised edition of the GHS (Rev. 11, 2025) incorporates refinements to criteria for certain physical hazards, including desensitized explosives (via H210 and H211) and aerosols, while maintaining the core structure of these statements.[25] The statements are organized by physical hazard classes, with severity levels (e.g., categories 1–4) dictating the specific phrasing to indicate the degree of risk. For instance, explosives classification relies on tests such as the BAM fallhammer apparatus to measure impact sensitivity, where lower energy thresholds indicate higher hazard categories and more severe statements. Below is a comprehensive list of standard H200-series statements, grouped by hazard type for clarity.Explosives and Desensitized Explosives (H200–H211)
These statements apply to substances capable of rapid energy release, including unstable explosives and those desensitized with agents like phlegmatizers to reduce sensitivity. Rev. 11 clarifies classification for desensitized explosives, emphasizing risks if the desensitizing agent diminishes.[25][27]| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H200 | Unstable explosive | Explosives, unstable |
| H201 | Explosive; mass explosion hazard | Explosives, Division 1.1 |
| H202 | Explosive; severe projection hazard | Explosives, Division 1.2 |
| H203 | Explosive; fire, blast or projection hazard | Explosives, Division 1.3 |
| H204 | Fire or projection hazard | Explosives, Division 1.4 |
| H205 | May mass explode in fire | Explosives, Division 1.5 |
| H206 | Extreme fire hazard | Explosives, Division 1.6 |
| H208 | Fire hazard; increased risk of explosion if desensitizing agent is reduced | Desensitized explosives, various categories |
| H209 | Explosive; unstable which is sensitive to shock or friction | Desensitized explosives, Type A |
| H210 | Explosive; mass explosion hazard which is sensitive to shock or friction | Desensitized explosives, Category 1 |
| H211 | Explosive; severe projection hazard which is sensitive to shock or friction | Desensitized explosives, Category 2 |
Flammable Gases, Aerosols, Liquids, and Solids (H220–H228)
These cover substances that can ignite easily or sustain combustion, with categories based on flash point, boiling point, and burning rate tests like the closed-cup flash point method. Updates in Rev. 11 enhance consistency for aerosol flammability classification.[25]| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H220 | Extremely flammable gas | Flammable gases, Category 1 |
| H221 | Flammable gas | Flammable gases, Category 2 |
| H222 | Extremely flammable aerosol | Flammable aerosols, Category 1 |
| H223 | Flammable aerosol | Flammable aerosols, Category 2 |
| H224 | Extremely flammable liquid and vapour | Flammable liquids, Category 1 |
| H225 | Highly flammable liquid and vapour | Flammable liquids, Category 2 |
| H226 | Flammable liquid and vapour | Flammable liquids, Category 3 |
| H227 | Combustible liquid | Flammable liquids, Category 4 |
| H228 | Flammable solid | Flammable solids, Categories 1–2 |
Self-Reactive Substances, Organic Peroxides, Pyrophoric, Self-Heating, and Water-Reactive Substances (H240–H261)
Self-reactive and organic peroxides statements address thermal instability, while pyrophoric, self-heating, and water-reactive ones highlight spontaneous ignition or gas evolution risks, evaluated via tests like the UN self-heating test or water reactivity assessments.| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H240 | Heating may cause a fire or explosion | Self-reactives/Organic peroxides, Types A–B |
| H241 | Heating may cause a fire | Self-reactives/Organic peroxides, Types B–C |
| H242 | Heating may cause a fire | Self-reactives/Organic peroxides, Types D–F |
| H250 | Catches fire spontaneously if exposed to air | Pyrophoric liquids/solids, Category 1 |
| H251 | Self-heating; may catch fire | Self-heating substances, Category 1 |
| H252 | Self-heating in large quantities; may catch fire | Self-heating substances, Category 2 |
| H260 | In contact with water releases flammable gases which may ignite spontaneously | Substances which in contact with water emit flammable gases, Category 1 |
| H261 | In contact with water releases flammable gas | Substances which in contact with water emit flammable gases, Categories 2–3 |
Oxidizing Gases, Liquids, and Solids; Gases Under Pressure (H270–H281)
Oxidizers promote combustion, classified by oxygen release potential via tests like the ammonium persulfate test, while pressurized gases statements warn of rupture risks from temperature increases. Rev. 11 provides updated criteria for chemicals under pressure.[25]| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H270 | May cause or intensify fire; oxidizer | Oxidizing gases, Category 1 |
| H271 | May cause fire or explosion; strong oxidizer | Oxidizing liquids/solids, Category 1 |
| H272 | May intensify fire; oxidizer | Oxidizing liquids/solids, Categories 2–3 |
| H280 | Contains gas under pressure; may explode if heated | Gases under pressure, Compressed gas/Liquefied gas |
| H281 | Contains refrigerated gas; may cause cryogenic burns or injury | Gases under pressure, Refrigerated liquefied gas |
Metals (H290)
This statement addresses chemical reactivity with metals, leading to corrosion, based on tests like the steel corrosion rate determination.| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H290 | May be corrosive to metals | Substances and mixtures corrosive to metals, Category 1 |
Health Hazard Statements
Health hazard statements in the Globally Harmonized System (GHS) encompass the H300 to H373 codes, which communicate specific risks to human health from exposure to hazardous chemicals, including immediate and delayed toxic effects. These statements are integral to hazard communication on labels and safety data sheets, enabling users to understand and mitigate risks such as poisoning, irritation, allergic reactions, and chronic damage to genetic material, organs, or reproductive systems.[25] Classification for these health hazards relies on toxicological endpoints derived from animal studies or human data where available. For acute toxicity, categories are assigned based on median lethal dose (LD50) for oral or dermal routes or median lethal concentration (LC50) for inhalation, with lower values indicating higher hazard levels (e.g., Category 1: oral LD50 ≤ 5 mg/kg body weight). Specific target organ toxicity (STOT) classifications use no observed adverse effect levels (NOAEL) from repeated exposure studies, where effects below guidance values trigger higher categories. Other hazards like carcinogenicity, mutagenicity, and reproductive toxicity are categorized using weight-of-evidence approaches from epidemiological, in vivo, or in vitro data, emphasizing mechanisms such as genotoxicity or endocrine disruption.[28] The following table lists all standard GHS health hazard statements (H300–H373), including their codes, full phrases, associated hazard classes, and categories as defined in the system:| Code | Phrase | Hazard Class | Category |
|---|---|---|---|
| H300 | Fatal if swallowed | Acute toxicity (oral) | 1 |
| H301 | Toxic if swallowed | Acute toxicity (oral) | 2 |
| H302 | Harmful if swallowed | Acute toxicity (oral) | 3 |
| H303 | May be harmful if swallowed | Acute toxicity (oral) | 4 |
| H304 | May be fatal if swallowed and enters airways | Aspiration hazard | 1 |
| H305 | May be harmful if swallowed and enters airways | Aspiration hazard | 2 |
| H310 | Fatal in contact with skin | Acute toxicity (dermal) | 1 |
| H311 | Toxic in contact with skin | Acute toxicity (dermal) | 2 |
| H312 | Harmful in contact with skin | Acute toxicity (dermal) | 3 |
| H313 | May be harmful in contact with skin | Acute toxicity (dermal) | 4 |
| H314 | Causes severe skin burns and eye damage | Skin corrosion/irritation; Serious eye damage/eye irritation | 1A, 1B, 1C; 1 |
| H315 | Causes skin irritation | Skin corrosion/irritation | 2 |
| H316 | Causes mild skin irritation | Skin corrosion/irritation | 3 |
| H317 | May cause an allergic skin reaction | Skin sensitisation | 1A, 1B |
| H318 | Causes serious eye damage | Serious eye damage/eye irritation | 1 |
| H319 | Causes serious eye irritation | Serious eye damage/eye irritation | 2 |
| H320 | Causes eye irritation | Serious eye damage/eye irritation | 2B |
| H330 | Fatal if inhaled | Acute toxicity (inhalation) | 1 |
| H331 | Toxic if inhaled | Acute toxicity (inhalation) | 2 |
| H332 | Harmful if inhaled | Acute toxicity (inhalation) | 3 |
| H333 | May be harmful if inhaled | Acute toxicity (inhalation) | 4 |
| H334 | May cause allergy or asthma symptoms or breathing difficulties if inhaled | Respiratory sensitisation | 1 |
| H335 | May cause respiratory irritation | Specific target organ toxicity (single exposure) | 3 (respiratory tract irritation) |
| H336 | May cause drowsiness or dizziness | Specific target organ toxicity (single exposure) | 3 (narcotic effects) |
| H340 | May cause genetic defects [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Germ cell mutagenicity | 1A, 1B |
| H341 | Suspected of causing genetic defects [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Germ cell mutagenicity | 2 |
| H350 | May cause cancer [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Carcinogenicity | 1A, 1B |
| H350i | May cause cancer by inhalation [route of exposure] | Carcinogenicity | 1A, 1B (inhalation specific) |
| H351 | Suspected of causing cancer [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Carcinogenicity | 2 |
| H360 | May damage fertility or the unborn child [state specific effect if known] [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Reproductive toxicity | 1A, 1B |
| H361 | Suspected of damaging fertility or the unborn child [state specific effect if known] [state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard] | Reproductive toxicity | 2 |
| H362 | May cause harm to breast-fed children | Reproductive toxicity (lactation) | - |
| H370 | Causes damage to organs [state all organs affected, if known] [state route of exposure if it is proven that no other routes of exposure cause the hazard] | Specific target organ toxicity (single exposure) | 1 |
| H371 | May cause damage to organs [state all organs affected, if known] [state route of exposure if it is proven that no other routes of exposure cause the hazard] | Specific target organ toxicity (single exposure) | 2 |
| H372 | Causes damage to organs [state all organs affected, if known] through prolonged or repeated exposure [state route of exposure if it is proven that no other routes of exposure cause the hazard] | Specific target organ toxicity (repeated exposure) | 1 |
| H373 | May cause damage to organs [state all organs affected, if known] through prolonged or repeated exposure [state route of exposure if it is proven that no other routes of exposure cause the hazard] | Specific target organ toxicity (repeated exposure) | 2 |
Environmental Hazard Statements
Environmental hazard statements in the Globally Harmonized System (GHS) communicate risks to ecosystems, primarily focusing on aquatic life and the ozone layer, using standardized phrases prefixed with "H4" codes. These statements alert users to the potential for chemicals to cause acute or long-lasting damage to aquatic organisms through toxicity, bioaccumulation, or lack of degradation, as well as broader atmospheric impacts. Classification relies on empirical data from toxicity tests, ensuring consistent global application on labels and safety data sheets.[5] The core of environmental hazards addresses aquatic toxicity, divided into acute (short-term) and chronic (long-term) categories. Acute classification uses median effective or lethal concentrations (EC50 or LC50) from 96-hour fish lethality tests, 48-hour crustacean immobilization tests, or 72/96-hour algal growth inhibition tests. For example, Acute Category 1 requires an EC50/LC50 of ≤1 mg/L, triggering H400 ("Very toxic to aquatic life"), while Category 3 uses >10 to ≤100 mg/L for H402 ("Harmful to aquatic life"). Chronic categories incorporate no-observed-effect concentrations (NOEC or similar), alongside assessments of rapid degradability (e.g., via OECD 301 tests) and bioaccumulation potential measured by bioconcentration factor (BCF) or log Kow. Chronic Category 1, for instance, applies if NOEC ≤0.1 mg/L and the substance is not rapidly degradable or has BCF ≥500, leading to H410 ("Very toxic to aquatic life with long lasting effects"). Severity escalates based on these combined factors, with Category 4 (H413: "May cause long lasting harmful effects to aquatic life") for substances showing potential chronic risks at >10 to ≤100 mg/L without rapid degradation or with BCF ≥30. For mixtures, classification often combines acute and chronic data using additive toxicity models, potentially integrating with physical or health hazards for comprehensive labeling.[29] The following table lists the standard GHS environmental hazard statements for aquatic hazards:| Code | Statement |
|---|---|
| H400 | Very toxic to aquatic life |
| H401 | Toxic to aquatic life |
| H402 | Harmful to aquatic life |
| H410 | Very toxic to aquatic life with long lasting effects |
| H411 | Toxic to aquatic life with long lasting effects |
| H412 | Harmful to aquatic life with long lasting effects |
| H413 | May cause long lasting harmful effects to aquatic life |
| Code | Statement | Hazard Class/Category Example |
|---|---|---|
| H420 | Harms public health and the environment by destroying ozone in the upper atmosphere | Hazardous to the atmospheric system (ozone depletion), Category 1 |
| H421 | Harms public health and the environment by contributing to global warming | Hazardous to the atmospheric system (global warming), Category 1 |
Regional and National Adaptations
European Union
The Classification, Labelling and Packaging (CLP) Regulation (EC) No 1272/2008 implements the United Nations Globally Harmonized System (GHS) of classification and labelling of chemicals within the European Union, establishing uniform criteria for identifying and communicating chemical hazards to protect human health and the environment. Adopted in 2008 and entering into force on 20 January 2009, the regulation progressively replaced earlier EU directives on dangerous substances and preparations, with full mandatory application to mixtures required by 1 June 2015.[31] The CLP is periodically amended to incorporate GHS revisions; recent updates align with earlier editions, with ongoing efforts to integrate elements from Rev. 11 (2025), such as clarified aerosol criteria.[32] The CLP also includes Specific Concentration Limits (SCLs) in its Annex I, which define threshold concentrations in mixtures triggering hazard classification, ensuring precise hazard identification beyond pure GHS building blocks.[31] A key feature of the EU adaptation is the use of supplemental EUH statements, which address hazards not fully covered by standard GHS H-statements and are mandatory where applicable under CLP Article 25. These EUH phrases provide additional precautionary information on labels and safety data sheets, reflecting the EU's emphasis on comprehensive risk communication. Examples include:- EUH001: "Explosive when dry," for substances that become explosive upon drying.[33]
- EUH014: "Reacts violently with water," indicating severe reactivity risks.[33]
- EUH029: "Contact with water liberates toxic gas," for water-reactive substances producing harmful gases.[33]
- EUH066: "Repeated exposure may cause skin dryness or cracking," for mild irritants without full classification.[33]
- EUH071: "Corrosive to the respiratory tract," for respiratory hazards not captured by standard categories.[33]
- EUH208: "Contains [name of sensitising substance]. May produce an allergic reaction," for undeclared allergens in mixtures.[33]
These statements are listed in Annex II of the CLP and must be included on labels when relevant, enhancing user protection.[31]