Q.01

What do hazard statements mean?

A hazard statement is a standard phrase on a chemical's label (and safety data sheet) that tells you what kind of hazard the substance or mixture poses and, where relevant, how severe it is. CLP defines it as "a phrase assigned to a hazard class and category that describes the nature of the hazards of a hazardous substance or mixture, including, where appropriate, the degree of hazard" [1]. Each statement has a code, such as H225 "Highly flammable liquid and vapour" [2].

How they work under EU CLP (Regulation (EC) No 1272/2008, consolidated text)

  • They follow from the classification. The label "shall include the relevant hazard statements in accordance with the classification" of the substance or mixture. Annex I sets out which statement goes with each hazard class and category [3].
  • The wording is fixed. Hazard statements "shall be worded in accordance with Annex III" [3]. Annex III gives the official text in every EU language [4].
  • Harmonised classifications take priority. If a substance has an entry in CLP Annex VI Part 3, the label must use the hazard statements from that entry. Statements for any other classifications the entry doesn't cover are added alongside [3].

What the codes tell you. Annex III sorts the statements into three tables:

  • H2xx, physical hazards: for example H200 "Unstable explosives" and H290 "May be corrosive to metals" [4][5].
  • H3xx, health hazards: for example H300 "Fatal if swallowed" (acute oral toxicity category 1 or 2), H301 "Toxic if swallowed" (category 3) and H302 "Harmful if swallowed" (category 4) [5]. The wording gets weaker as the category gets less severe; that is the "degree of hazard" in the definition.
  • H4xx, environmental hazards: for example H400 "Very toxic to aquatic life" and H410 "Very toxic to aquatic life with long lasting effects" [6].
  • EUH statements: these are EU-specific statements, such as EUH440 "Accumulates in the environment and living organisms including in humans" [4].

Some statements have a placeholder for you to fill in. H350 reads "May cause cancer " [7].

When a product has several classifications. Every hazard statement that results from the classification "shall appear on the label, unless there is evident duplication or redundancy" (Article 27) [8]. Annex III lists where a statement "may be omitted": for example, H400 can be left off if H410 is assigned, and H318 if H314 is assigned. Suppliers may also use the combined statements Annex III provides, for example to show the route of exposure [4].

How they differ from other label elements:

  • Precautionary statements (P-codes) describe recommended measures to minimise or prevent harm from exposure. Hazard statements describe the hazard itself [1].
  • Signal words ("Danger" for the more severe categories, "Warning" for the less severe) show the relative level of severity [1].

Approach: I used the current consolidated text of EU CLP (Articles 2, 21 and 27 and Annex III), plus the Norwegian Environment Agency's list of CLP hazard statements for the H225 and H350 wording. This covers the EU rules only; GB CLP and other GHS-based systems have their own legal texts, which I didn't check here.

Q.02

How are precautionary statements different?

Hazard statements say what the danger is; precautionary statements (P-statements) say what to do about it. CLP defines precautionary statements as phrases describing "recommended measure(s) to minimise or prevent adverse effects resulting from exposure" [1]. Both must go on the label, but they are chosen and limited by different rules.

How precautionary statements are chosen (CLP Article 22)

  • The label "shall include the relevant precautionary statements."
  • They "shall be selected" from the label-element tables in Annex I, Parts 2 to 5.
  • They are selected using the criteria in Annex IV Part 1, "taking into account the hazard statements and the intended or identified use or uses" of the substance or mixture.
  • Their wording must follow Annex IV Part 2 [9].

This is the main difference. The hazard statement follows directly from the classification. The precautionary statements depend on the hazard statements and also on how the product is used. Consumer products, for example, get statements that industrial products may not.

Supplier flexibility (Annex IV) Annex IV sets out a matrix of recommended precautionary statements for each hazard class and category. Its main rules [10]:

  • "All specific elements relating to particular hazard classes shall be used." General statements not linked to a hazard class "shall also be used where relevant."
  • Suppliers are encouraged to combine and consolidate statements to save label space and improve readability.
  • Labels and SDSs "may incorporate minor textual variations", such as synonyms or regional spelling, as long as "the safety advice is not diluted or compromised." Hazard statements have no equivalent allowance: Article 21 requires the Annex III wording [3].
  • Many statements need the supplier to fill something in:
    • Text in [square brackets] is used only in certain circumstances.
    • A slash / means you choose between options.
    • "…" means you add the details. P230 "Keep wetted with …" is one example; the manufacturer or supplier specifies the material.
    • Column 5 of the table gives the conditions for each of these.

How many go on the label (CLP Article 28)

  • Statements that are "clearly redundant or unnecessary given the specific substance, mixture or packaging" "shall be omitted."
  • For products supplied to the general public, one statement on disposal of the product and its packaging "shall appear on the label, unless not required under Article 22." In other cases a disposal statement is not required where disposal clearly presents no hazard to health or the environment.
  • "Not more than six precautionary statements shall appear on the label, unless necessary to reflect the nature and the severity of the hazards" [11].

Hazard statements have no such cap. Every one resulting from the classification must appear unless it is an evident duplicate (Article 27) [8].

How the P-codes are grouped (Annex IV Part 1)

  • P1xx, general: for example P102 "Keep out of reach of children." (consumer products). P103 is omitted where P202 is used [10].
  • P2xx, prevention: for example P201 and P202 for carcinogens, mutagens and reproductive toxicants. P210 "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking." applies to flammable and oxidising classes [12].
  • P3xx, response: for example P301 "IF SWALLOWED:" and P302 "IF ON SKIN:" [13], and P331 "Do NOT induce vomiting." [14].
  • P4xx, storage: for example P402 "Store in a dry place." [15].
Hazard statements (H)Precautionary statements (P)
PurposeDescribe the nature and degree of the hazardRecommend measures to prevent or minimise harm
Driven byClassification onlyHazard statements plus intended or identified use
WordingFixed (Annex III)Annex IV wording, minor variations allowed
Number on labelAll, minus evident duplicationNormally no more than six

Approach: I used the current consolidated text of EU CLP (Articles 2, 21, 22, 27 and 28, and Annex IV). This covers the EU rules only; I didn't check GB CLP or other GHS-based systems.

Q.03

Are the codes the same in Britain and America?

Britain uses the same codes as the EU, but the US doesn't use them at all. GB CLP keeps the EU system: H-codes, P-codes and EUH statements, with the same wording. The US OSHA Hazard Communication Standard lists its hazard and precautionary statements as plain text with no codes. Most of that text is the same GHS wording, though.

Great Britain (GB CLP, the assimilated Regulation (EC) No 1272/2008)

  • Hazard statements: the rules match the EU text. The label "shall include the relevant hazard statements in accordance with the classification", and they "shall be worded in accordance with Annex III". The one structural change is that harmonised classifications come from the GB mandatory classification and labelling list (GB MCL), not EU Annex VI [16].

  • Precautionary statements: these are selected from Annex I, using the Annex IV Part 1 criteria and "taking into account the hazard statements and the intended or identified use", and worded per Annex IV Part 2 [17].

  • Same codes and wording. For example:

    • H224 "Extremely flammable liquid and vapour" and H225 "Highly flammable liquid and vapour" [18]
    • H331 "Toxic if inhaled." [19]
    • P210 "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking." [20]
    • P302 + P352 "IF ON SKIN: Wash with plenty of water/…" [21]

    The GB Annex I tables assign them by code. For flammable liquids, for instance, it's H225 plus P210, P233, P240 and so on [22].

  • EUH statements are kept in GB Annex II under their EUH codes, for example EUH066 "Repeated exposure may cause skin dryness or cracking" and EUH208 "Contains (name of sensitising substance). May produce an allergic reaction" [23][24].

  • Where GB and the EU have split: the current EU CLP text has the newer EU-only statements, such as EUH380 for endocrine disruptors [25] and EUH440 (mentioned in the earlier answer). I couldn't find EUH380 or EUH440 anywhere in the GB CLP text.

United States (OSHA Hazard Communication Standard, 29 CFR 1910.1200)

  • Same concepts. OSHA defines a hazard statement almost word for word as CLP does: "a statement assigned to a hazard class and category that describes the nature of the hazard(s) of a chemical, including, where appropriate, the degree of hazard." A precautionary statement "describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposure to a hazardous chemical, or improper storage or handling" (29 CFR 1910.1200(c)).

  • What the label needs. Shipped containers must carry a product identifier, signal word, hazard statement(s), pictogram(s), precautionary statement(s), and a US name, address and phone number. Items (i) to (v) must follow Appendix C and be "prominently displayed, and in English" (1910.1200(f)(1)-(2)).

  • No codes. The Appendix C.4 tables give each statement as text only. Acute oral toxicity, for example, is "Fatal if swallowed" (categories 1 and 2), "Toxic if swallowed" (category 3) and "Harmful if swallowed" (category 4). The precautionary statements are also text, such as "Do not eat, drink or smoke when using this product." and "Store locked up." (Appendix C). The text is the same as the GHS-based CLP wording, but there's no H or P number next to it.

  • Same drafting conventions as CLP Annex IV:

    • "/" means choose between the phrases.
    • "…" means the supplier adds the details.
    • [square brackets] mean the text is used only in certain circumstances.
    • Italics mark conditions that do not go on the label.
    • Statements may be combined, and minor textual variations are allowed if "the safety advice is not diluted or compromised" (C.2.4.2 to C.2.4.7).
    • Unlike CLP, a statement may also be left off if the supplier "can demonstrate" it is inappropriate (C.2.2.2, C.2.4.9) (Appendix C).

  • Scope differences that change which statements exist:

    • OSHA's hazard classes are physical and health hazards only; its definitions list no environmental class.
    • It uses eight pictograms.
    • It hasn't adopted some GHS categories, such as acute toxicity category 5.
    • It adds "hazard not otherwise classified" (HNOC). HNOC doesn't have to be addressed on the shipped label (1910.1200(c), (f)(1)).

    So the H4xx aquatic statements and the EUH statements have no OSHA counterpart.

EU CLPGB CLPUS OSHA HCS
H/P codesYesYes, same numberingNone in Appendix C; text only
EUH statementsYes, incl. EUH380/EUH440Yes (e.g. EUH066, EUH208); EUH380/EUH440 not foundNo
Harmonised listAnnex VIGB MCL listNone; manufacturer/importer classifies
Environmental hazardsYesYesNot in scope

Approach: I searched the GB CLP text (Articles 21-22, Annexes I-IV) and compared it with the current EU CLP text. The datasets don't hold the US Hazard Communication Standard, so I read 29 CFR 1910.1200 and its Appendix C on OSHA's official site.

Q.04