Last reviewed 31 October 2012

This article by Gill Pagliuca reviews some of the more common classification and labelling issues that subscribers will have encountered, or may encounter as they reclassify their mixture over the next few years, or as they receive products from their suppliers which have been relabelled according to the new classification regime.


The Classification, Labelling and Packaging of Substances and Mixtures Regulation (EC) No. 1272/2008 (CLP) has now been in force for over three years, and although the transitional arrangements do not expire until June 2015, it can no longer be considered completely new. Much experience has been obtained now in implementing its provisions, and this has brought to light many practical issues in both classification and labelling.

Classification issues

Discrepancies between CLP and CHIP (DPD) classifications

A concern that users often raise is that the CLP classification shown for a product is different to the classification under the CHIP regulations. There may be several reasons for this.

  • The classification criteria may be different bringing more products into scope of the regulations, or in some cases dropping them out of scope.

  • When reclassifying to CLP new data may have been identified which affects the classification under both CLP and CHIP.

  • The classification hasn’t changed, but the way it is described may be different, giving the impression that it has changed.

Some of the more common reasons that a classification may differ are discussed further in this article. REACH does require that SDS authors include details of revisions to the SDS in section 16, but this rarely indicates why a classification has changed. Including suitable information would be helpful for users so that they can react appropriately to any changes. However, if a user is unsure as to why the classification differs, then the best thing is always to ask the supplier.

Discrepancies where the hazard classification criteria have changed

Inevitably, the introduction of CLP has resulted in some changes in the scope of substances and mixtures that are classified as hazardous and labelled accordingly, although the European Commission did its best to minimise this when introducing CLP by not taking up some of the optional categories for classification that are included in the GHS.

Mixtures containing corrosive or irritant component substances, and mixtures containing substances classified as hazardous to reproduction, are likely to be particularly affected, due to reductions in the thresholds for these types of substances used when calculating the classifications of mixtures. Of particular concern to users will be mixtures which were not classified as hazardous at all under CHIP, but which are now classified as hazardous. Table 1 shows which mixtures are most likely to be affected.

Table 1

Not classified under DPD (CHIP)

Possible classification under CLP


Mixtures containing 1–5% of R34

Skin irritant Category 2

Mixtures containing less than 5% of R34 were not classified under DPD (CHIP). However, under CLP a much lower generic concentration limit of 1% applies, resulting in the mixture being classified as irritant.

Mixtures containing 10–20% of R38 substances

Skin irritant Category 2

Mixtures containing less than 20% of R38 were not classified under DPD (CHIP). However, under CLP a much lower generic concentration limit of 10% applies, resulting in the mixture being classified as irritant.

Mixtures containing 1–3% of R41 or R34 substances

Eye irritant Category 2

Mixtures containing less than 5% of R41 or R34 substances were not classified under DPD (CHIP). However, under CLP a much lower generic concentration limit of 1% applies, resulting in the mixture being classified as irritant (see also next entry).

Mixtures containing 3–5% of R41 or R34 substances

Serious eye damage Category 1

Mixtures containing less than 5% of R41 or R34 substances were not classified under DPD (CHIP) and between 5 and 10% were only classified as irritant. Under CLP much lower generic concentration limits apply, and mixtures containing 3% or more of R41 or R34 substances will be classified as Serious Eye Damage Cat. 1 (corrosive pictogram).

Mixtures containing 10–20% of R36 substances

Eye irritant Category 2

Mixtures containing less than 20% of R36 were not classified under DPD (CHIP). However, under CLP a much lower generic concentration limit of 10% applies, resulting in the mixture being classified as irritant.

Mixtures containing 3–5% of R63 or R62 substances

Reproductive toxicant Category 2

Mixtures containing less than 5% of R63 or R62 were not classified under DPD (CHIP). However, under CLP a lower generic concentration limit of 3% applies, resulting in the mixture being classified.

Mixtures containing 0.3–0.5% of R60 or R61 substances

Reproductive toxicant Category 1A/1B

Mixtures containing less than 0.5% of R60 or R61 were not classified under DPD (CHIP). However, under CLP a lower generic concentration limit of 0.3% applies, resulting in the mixture being classified.

Where mixtures have changed classification due to changes in the way that CLP classifies them, users may feel they need to introduce a whole range of additional risk management measures to reflect this change. This may be particularly the case for mixtures containing 3–5% of a component classified for serious eye damage, which were not classified as hazardous under CHIP, but under CLP will be supplied with a corrosive pictogram on the label. However, bear in mind that although the classification of the mixture has changed, the intrinsic hazard of the mixture has not altered, and if the previously used risk management measures were adequate, there is no reason why they should not continue to be so.

Other areas where increases in the scope of CLP, compared to CHIP, may lead to more products being classified include substances classified for Specific Target Organ Toxicity — Repeated Exposure (STOT RE), which is equivalent to R48 plus one or more of R23, 24, 25 or R20, 21, 22 under CHIP. STOT RE now includes substances demonstrating significant effects at higher doses than under CHIP – in the case of oral exposure doses of up to 100mg/kg/day for oral exposure under CLP, compared to 50mg/kg/day under CHIP, with similar pictures for dermal and inhalation exposures.

More low viscosity hydrocarbons that may present an aspiration hazard will also be classified, with the criteria changing from substances and mixtures with a viscosity of less than 7mm2/sec under CHIP to those with a viscosity of <20mm2/sec under CLP.

For physical hazards, the expectation is that there will not be many significant changes in the number of classified products due to changes in scope of the regulation. A few additional substances and mixtures may be classified as flammable due to the alignment of the flammable liquids criteria with GHS (flash point up to 60°C compared to 55°C) but since the GHS and the transport of dangerous goods regulations are already aligned this is not expected to bring about any surprise changes. The inclusion of hazard classes for gases under pressure, self-heating substances and metal corrosivity are new to supply, but again, as these hazard classes are already part of the transport classification system their inclusion should not result in many surprises for suppliers but may for end users who may not have seen the outer packaging of fully regulated products or who saw them in a limited quantity package.

Metal corrosivity

Metal corrosion is a new hazard for supply classification under CLP but is not a new concept. Metal corrosivity has been included in the classification criteria for the transport of dangerous goods for many years so classification should have already been considered for this purpose. However, awareness of, and testing for, this property is arguably much lower than it should be, and there are probably many products currently on the market which should be considered corrosive to metals but which have not been properly tested, classified and labelled.

For example, we all know that salt can be corrosive to steel — we can see the effects of the use of road salt on our cars and on steel structures subjected to sea water, and there are many scientific papers devoted to the issue of salt corrosion to steel. Yet the REACH registration dossier for sodium chloride reports “data lacking” as the reason for no classification for this endpoint.

CLP requires that, where there is insufficient information available to conclude on classification for physical properties, then new testing must be carried out. This would then lead to the conclusion that “data lacking” is not an acceptable reason for not concluding the classification of a substance or mixture for its physical hazards under CLP. In the case of salt there is a huge body of literature on its corrosive effects to metal, but it appears as though the registrants have not assessed this property.

Discrepancies between lists — Annex VI and Dangerous Goods List

There have been many discrepancies identified between published lists of classifications including CLP Annex VI and the UN Dangerous Goods List. In particular, a number of papers have been submitted to the UN Sub-Committee of Experts on the Transport of Dangerous Goods on this subject, which can be found on the UN ECE website.

One example of this discrepancy is dichloromethane. In the UN Dangerous Goods List, dichloromethane is classified as Class 6.1, Packing Group III. The substance is listed in CLP Annex VI with a classification for suspected carcinogenicity. In the REACH Registration dossier, the registrant proposes additional classifications for skin and eye irritation and for specific target organ toxicity effects. However, it is not classified for acute toxicity, and the animal toxicity data does not support such a classification.

Unfortunately, due to the passage of time, the original papers from the UN Transport of Dangerous Goods Sub-Committee that would have set out the reasoning behind the classification of dichloromethane for the transport classification are not available. There may have been additional data available to the UN Sub-Committee at the time they agreed their classification, such as practical human experience of exposure to the substance, that was responsible for their decision. Certainly there are reports in the literature of people who have suffered significant or even fatal effects from the accidental inhalation or ingestion of dichloromethane, although these are more often attributed to the narcotic and corrosive effects of the substance.

Looking at these reports and the proposed classification under REACH, dichloromethane clearly has the potential to cause some nasty effects. However, such discrepancies between supposedly harmonised classification systems have the potential to cause confusion amongst all those along the supply chain.

Calcium oxide is another example where inconsistencies between supply and transport classifications may cause concern. Calcium oxide, more commonly known as quick lime, is classified in the Dangerous Goods List as Class 8, Packing Group III. Although not listed in Annex VI, the industry agreed classification for the substance is that the substance causes severe damage to eyes, and is irritating to the skin and to the respiratory tract. It does not meet the criteria for skin corrosivity. The REACH registration dossier for the substance also demonstrates that it does not meet the criteria for corrosivity to metals. Although listed in ADR, the substance has been exempted from this regulation; yet it is still regarded as hazardous for other modes of transport.

To some extent, CLP may lessen user confusion as substances and mixtures deemed to cause serious eye damage will be labelled with the GHS pictogram for corrosivity, rather than the lesser exclamation mark which is equivalent to the St Andrews Cross symbol used under CHIP.

There are many more examples of substances where there are significant differences in the classification between different lists. Efforts to understand why these discrepancies exist have focused on the likelihood that different data sets were used to derive the classifications, and also that different classification criteria may have been in place at the time that the classification was agreed. Unfortunately, resource limitations mean that there is unlikely to be any systematic effort to resolve these issues. Instead, it is most likely that it will be left to industry to make the case for the entries in each list that most concern them, and then to persuade the relevant authorities to push each case at the appropriate committees.

Specific Concentration Limits

Specific Concentration Limits (SCLs) are a concept specific to the EU and have been carried through to CLP from the Dangerous Substances Directive (DSD). SCLs are used when calculating the likely hazard of a mixture and are assigned to substances when there is good evidence that the contribution of the substance to the hazard of a mixture will be significantly greater (or smaller) than would be indicated if the generic concentration limits for the endpoint in question were used for determining the hazard classification. SCLs are given in Annex VI, and may also now be set by REACH registrants and CLP notifiers when they submit their classifications to ECHA.

Because SCLs are an EU concept and are not used in the GHS or by other countries that have implemented the GHS, there is no advice on their use in the GHS and therefore the regulatory text for CLP, on how to use these limits when assessing the hazard of a mixture. Instead guidance and formulae for assessing the mixture toxicity when an SCL has been assigned can be found in the guidance on the application of the CLP classification criteria. These are very similar to the old CHIP/DPD formulae.

As SCLs are only used in the EU, then mixtures containing a substance to which an SCL has been assigned may be classified differently in other countries that have implemented the GHS, such as the USA or Japan, where the generic concentration limits have been applied. This may cause problems for suppliers shipping outside the EU, or for importers who may need to re-assess mixture classifications even where these have been carried out using the standard GHS concentration limits.

CLP is a hazard-based classification scheme, not risk-based

A question that is often asked by suppliers is, “I have a product classified as toxic by inhalation, but inhalation is not possible/not likely, do I have to classify it for this effect?”

Suppliers often try to reduce the hazards of the products they supply, eg by putting a powder that is toxic by inhalation into a wet slurry or paste to reduce the likelihood of inhalation. This is an excellent risk management measure. However, it should be recognised that the intrinsic hazard of the product remains the same. The toxicity has not gone away, but the likelihood of exposure by inhalation has been reduced. If information about the inhalation toxicity hazard was omitted from the label then there would be nothing to stop the user from deciding, for example, that it might be a good idea to spray the product, which would lead to a high potential for inhalation exposure to particulates of the product. Therefore, the product still needs to be classified and labelled as toxic by inhalation, so that the user understands the full picture.

The exception to this is where it can be conclusively demonstrated through experimental evidence that the hazardous product is in a form where it is not bio-available and therefore classification is not required.

Use of precautionary statements for non-classified products

Some products, although not classified as hazardous, may nevertheless have some Precautionary Statements (or indeed Safety Phrases) applied to the label and listed in the Safety Data Sheet (SDS). This is often the result of the supplier deciding that some safety information is desirable on the label and uses the standard phrases from CLP (or CHIP) since they provide good advice and are easily translated. Neither CLP nor CHIP prevents the use of these phrases, although it may be helpful in avoiding confusion if the supplier makes it clear that they have been voluntarily applied by placing them in the supplementary labelling section in section 2.2, or including a statement on the SDS to the effect that they have been voluntarily applied.

Labelling issues

The label is not the same as the classification

Another area for potential confusion exists where the labelling reported for a product in section 2.2 of the SDS does not match the classification given in section 2.1. This may arise when products are classified as both corrosive to skin (Skin Corr. 1A/1B/1C, H314) and causing severe eye damage (Eye Dam. 1, H318). Because the Hazard Statement H314 Causes severe skin burns and eye damage covers both situations, it is not necessary to also include H318 Causes serious eye damage. A similar situation exists for products classified as category 1 for both acute aquatic toxicity (Aquatic Acute 1, H400) and chronic aquatic toxicity (Aquatic Chronic 1, H410), as H410 Very toxic to aquatic life with long lasting effects covers both situations and makes H400 Very toxic to aquatic life unnecessary.

Another situation is where mixtures are assigned one of the special labelling phrases listed in Annex II, Part 2. These phrases are normally included in the supplementary labelling section of the label, and do not form part of the classification that would be reported in section 2.1 of the SDS.

Small quantities provisions not in CLP

The CHIP Regulations included some very useful provisions for small quantities of hazardous products that allow the supplier to omit hazard labels where the quantity is so small that there is no foreseeable risk under conditions of supply, use and disposal, to persons or the environment. Unfortunately, this concept is not included within the GHS or CLP, and labels must be applied no matter how small the quantity of the product being supplied.

Labelling of very small packages

Labelling can be very difficult in the case of very small samples or R&D chemicals which may be supplied in quantities of just a few millilitres. For these very small containers there simply is not enough room on the container to include even the reduced label elements allowed for packages smaller than 125 millilitres as set out in CLP Annex I Part 1.5 and still keep the label readable without a magnifying glass.

This issue has been raised at the UN GHS Sub-Committee of Experts, and work is ongoing to agree on practical solutions to this problem. For those interested in following the debate, the papers can be found on the UN ECE website . Since such small containers are usually supplied in intermediate packaging, then the most pragmatic approach is to include as much as possible of the most essential information on the container (name, pictograms) and apply the full label to the larger intermediate packaging layers. While not officially sanctioned by the enforcement authorities, this approach is the one that is being most commonly adopted by industry.

Blank diamonds

Under the CHIP Regulations, it was common practice for many suppliers to use pre-printed label stock with an orange-coloured area over which they printed any necessary hazard symbols. This allowed suppliers to keep printing costs down as they only needed to print in one colour. To use a similar practice under CLP a number of empty red diamonds would need to be pre-printed on the label stock, not all of which may then be required to be used. This has led to much discussion over what to do about blank diamonds. Leaving the diamond blank could cause confusion to the user, as he/she could not be sure that the supplier has not left off relevant pictograms through a printing mistake (although this could equally have happened when labelling to CHIP, without any indication to the fact that data is missing).

ECHA has acknowledged this issue and in its FAQs on CLP, it states that although CLP does not explicitly disallow blank diamonds, CLP does include provisions which require that any information given in addition to the minimum mandatory labelling must not contradict or cast doubt on the mandatory label information. ECHA has therefore recommended that, if pre-printed labels must be used, any unnecessary diamonds should be completely blacked over with a solid overprint to avoid any user misunderstanding. They do not recommend other alternatives that have been suggested, such as printing a # symbol in the diamond, or the words “no symbol assigned”. Such blacked out diamonds are still undesirable, but it is recognised that there may be a period when this solution will be used until more affordable printing technologies become available, particularly for SMEs.

The authors of the new Hazcom 2012 Regulation to implement the GHS in the USA have clearly watched this debate with interest, as the Hazcom 2012 Regulation specifically prohibits the appearance of blank diamonds on labels.

Interface with transport labelling

Another area of confusion for many is the interface between CLP and transport labelling, where a package contains goods classified as hazardous to CLP but which are not considered dangerous for transport. Whether this was required under the previous regulations was a matter of debate, however CLP has clarified the matter. Goods which are classified as hazardous under CLP, but which are not labelled under transport of dangerous goods regulations, will need to carry the CLP labelling on the outer packaging.

This requirement has raised a number of questions. Firstly, are goods carried under Limited Quantity (LQ) or Excepted Quantity (EQ) packaging provisions considered to be “labelled” under transport since the LQ and EQ graphic is referred to as a "mark" in the regulations and not a "label"? Looking at the spirit of the CLP regulation, the intention of this requirement is to alert carriers to the presence of potentially hazardous goods. The LQ or EQ mark fulfills this function. The recent ECHA guidance document on CLP labelling also makes it clear that in this case transport labelling means all applicable labels and marks, and there is no need to apply additional CLP labelling. CLP explicitly allows both CLP and transport labelling to be used, but it is optional. Secondly, if CLP labels are required on outer transport packaging, do they have to meet the transport requirements, such as sea immersion? CLP sets out no such requirements and the same labels as are applied to the inner package may be used. Thirdly, what should you do if you send a package containing a large number of small samples which are all labelled differently? Do you have to apply the labels for every container to the outer packaging? There is no easy answer to this question. Clearly it is not desirable to cover the entire outer surface of the package with a plethora of labels. Whilst the CLP labelling guidance notes the problem, it does not offer a clear solution, but only suggests the rules be applied with care, as several individual labels may not give a coherent picture of the hazards.

Other issues

ORs submitting notifications

When CLP came into force there was much discussion over whether Only Representatives (ORs) could fulfil the obligation to submit notifications on behalf of the group of importers whose registration duties they are assuming. Early opinions from ECHA indicated that this was not a role for the OR unless the OR was also an importer. More recently ECHA has revised this opinion, but has recommended that, since the legal obligation remains with the importer, the OR and the importer document that the OR is submitting the notification on behalf of the importer and that the importer understands that they remain legally responsible for this notification. An exchange of letters between the OR and the importer will therefore be necessary, as it is when the OR takes on the REACH registration obligations for the importer.

CLI issues

ECHA has recently updated the Classification and Labelling Inventory (CLI) and resolved the issue where registered classifications of "not hazardous" did not appear. However, all is still not well with the way that registered classifications are reported. For example, many dossiers contain both an official classification from Annex VI of the CLP Regulation, and a self classification based on the evidence in the dossier which may propose additional classifications for more hazard endpoints or more severe hazard classifications than are included in Annex VI. Other dossiers may contain different classifications for different grades of the substance or different forms. The CLI now reports all these classifications as registered classifications, but any notes added by the registrant to explain the different classifications are not visible in the CLI. It will be necessary for users to view the disseminated dossier to get a clearer picture of which of these classifications is the correct one for them to use.

Communication issues

For users of products labelled to CLP, understanding the new classifications and labels may require some education and training from their suppliers. Although basic guidance materials have been made available, there has not been a widely publicised campaign to help users understand the new classifications and labels, and many of the downstream regulations, such as COSHH, etc that are impacted by the changes have yet to be updated.

As noted above, the changes to the calculation methods for corrosives and irritants will likely result in considerably more products being classified and labelled for these endpoints. Helping customers to understand that the product has not changed, only the labelling, may be necessary. Also, that they do not immediately need to change their COSHH assessments, PPE, etc, if their current measures are providing adequate control.

Another issue that has caused some initial confusion among users is the classification of CMRs (carcinogens, mutagens, reproductive toxins) and mixtures containing them. Although there is no significant change in the scope of CLP for these hazard endpoints, there is some potential for confusion in the way they are described. For each of these endpoints the hazard class is sub-divided into three categories under CHIP — categories 1, 2 and 3. Categories 1 and 2 are the most hazardous, and their use must be strictly controlled. Certain groups are also excluded from using them. In CLP, these hazard endpoints are also sub-divided into three categories — 1A, 1B and 2, which are equivalent to the CHIP categories 1, 2 and 3. In this case, CLP category 2 is equivalent to CHIP category 3. This clearly creates the potential for confusion among downstream users, and suppliers whose products fall into these classifications may need to make sure their customers understand the difference, as many will react upon seeing “category 2” without understanding that the category numbers have been changed.