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EU Classification and labelling of sodium hydroxide (CAS number 1310-73-2)

1. Classification and labelling according to DSD

Sodium hydroxide is listed on Annex I of Directive 67/548/EEC (DSD). The harmonized

classification and labelling according to this Directive is given hereafter.

Classification

Indication of danger: C - corrosive

R-phrase: R35 - causes severe burns

Labelling

Indication of danger: C - corrosive

R-phrase: R35 - causes severe burns

S-phrases:

(S1/2 - keep locked up and out of reach of children)

S26 - in case of contact with eyes, rinse immediately with plenty of water and seek medical

advice

S37/39 - wear suitable gloves and eye/face protection

S45 - in case of accident or if you feel unwell, seek medical advice immediately (show the

label where possible)

Specific concentration limits:

C; R35 (Corrosive; Causes severe burns): C ≥ 5 %

C; R34 (Corrosive; Causes burns): 2 % ≤ C < 5 %

Xi; R36/38 (Irritant; Irritating to eyes and skin): 0,5 % ≤ C < 2 %

2. Classification and labelling according to CLP

Sodium hydroxide is listed on Annex VI of Regulation (EC) No 1272/2008 (CLP). The

harmonized classification and labelling according to this CLP regulation is given hereafter.

Classification

Hazard class and category: Skin corrosive; category 1A

Hazard statement: H314: Causes severe skin burns and eye damage

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Labelling

Signal word: Danger

Hazard Pictogram Codes and Symbols: GHS05: corrosion

Hazard statements: H314: Causes severe skin burns and eye damage

Specific concentration limits

Skin Corr. 1A; H314 (Causes severe skin burns and eye damage): C ≥ 5 %

Skin Corr. 1B; H314 (Causes severe skin burns and eye damage): 2 % ≤ C < 5 %

Skin Irrit. 2; H315 (Causes skin irritation): 0,5 % ≤ C < 2 %

Eye Irrit. 2; H319 (Causes serious eye irritation): 0,5 % ≤ C < 2 %

3. Self classification and labelling according to CLP

Sodium hydroxide is listed on Annex VI of the CLP Regulation and this classification and

labelling is legally binding (obligatory). However, in addition it is proposed to classify the

substance as:

Hazard class and category: Corrosive to metals; category 1

Hazard statement: H290: May be corrosive to metals

Based on this additional classification proposal, the substance has to be labelled with:

Signal word: Warning

Hazard Pictogram Codes and Symbols: GHS05: corrosion

Hazard statements: H290: May be corrosive to metals

Based on the obligatory labelling, mentioned in chapter 2 of this document, and based on

the additional proposed labelling, mentioned in chapter 3 of this document, the following

selection of Precautionary Statements is proposed for the labelling of the substance sodium

hydroxide:

P260: Do not breathe dust/fume/gas/mist/vapours/spray.

P280: Wear protective gloves/protective clothing/eye protection/face protection.

P303 + P361 + P353: IF ON SKIN (or hair): Remove/Take off immediately all

contaminated clothing. Rinse skin with water/shower.

P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes.

Remove contact lenses, if present and easy to do. Continue rinsing.

P310: Immediately call a POISON CENTER or doctor/physician.

The Precautionary Statements mentioned above are proposed for industrial use of the

substance NaOH. Other or additional Precautionary Statements may be more appropriate

for professional and/or consumer use of NaOH.

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4. Commission Regulation No 286/2011

In March 2011 Commission Regulation No 286/2011 was published in the Official Journal

of the EU. This Regulation is amending, for the purposes of its adaptation to technical and

scientific progress, the CLP Regulation (No 1272/2008). It contains amendments

concerning, inter alia, new subcategories for respiratory and skin sensitisation, the revision

of the classification criteria for long-term hazards (chronic toxicity) to the aquatic

environment and a new hazard class for substances and mixtures hazardous to the ozone

layer.

Sodium hydroxide has neither a respiratory nor a skin sensitization potential and therefore

the amendment has no effect on the classification of sodium hydroxide.

Reliable chronic studies with fish, crustaceans and algae (or other aquatic plants) are not

available for sodium hydroxide and these studies are scientifically unjustified. Furthermore

NaOH is rapidly neutralized in the aquatic environment and the substance has no

bioaccumulation potential. For this reason there is no need to classify NaOH for long-term

aquatic hazards based on the criteria of Commission Regulation No 286/2011.

NaOH is not hazardous to the ozone layer.

It can be concluded that the amendments of the CLP Regulation, introduced by

Commission Regulation No 286/2011, have no effect on the classification and labelling of

sodium hydroxide. The correct classification and labelling of NaOH is mentioned in section

3 and 4 of this document.