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EC number: 268-615-9 | CAS number: 68131-33-9 The solution formed by reacting the sodium salts of green liquor with calcium hydroxide.
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Hazard for air
Hazard for terrestrial organisms
Hazard for predators
Additional information
White liquor is registered as a transported isolated intermediate and is manufactured and consumed under strictly controlled conditions during its whole life cycle. The derivation of PNECs is required for the chemical safety assessment (CSA) of substances manufactured/imported/used in quantities from 10 t/y onwards. CSA does not need to be performed for transported isolated intermediates.
The conclusion on classification is based on aquatic acute toxicity data according to Annex VII in the REACH regulation, applied for transported isolated intermediates, where no terrestrial or long-term aquatic toxicity information is required.
No data on sediment or terrestrial toxicity of White liquor was available based on an extensive literature search. White liquor recycles in the pulping process and no spillages occur in normal process conditions. Hence little ecotoxicological studies have been conducted on White liquor. The dry solids/water ratio of the tested sample was 17/83 % by weight.
White liquor was the most toxic to Daphnias (EC50 4.4 mg/l (dwt.) (26 mg/l (substance wet weight)), which drives the classification.
The EC50 value is higher than the limit value for the acute classification Aq. Acute Cat.1 (< 1 mg/l).
The criteria for Chronic Cat. hazard classification requires additional information of (bio)degradability and/or bioaccumulation and/or chronic toxicity. Based on scientific literature information, sulfide (S2-) which is known to be the most toxic constituent of White liquor, is readily oxidised in aquatic environment in abiotic and microbial processes.
Conclusion on classification
White liquor is an aqueous alkaline solution of inorganic cooking chemicals in kraft or soda pulping process. The source materials for White liquor are sodium salts of green liquor and calcium oxide. White liquor is a UVCB substance with variable composition. Therefore the exotoxicological properties are also somewhat variable and dependent on the sulfide content of the mixture.
The aquatic toxicity of a representative White liquor sample were tested in a GLP laboratory during 2009-2010 (the Key studies). No additional data on ecotoxicological endpoints was found through extensive literature searches.
According to the experimental results the ecotoxicological properties of White liquor were:
- Hazardous to the acuatic environment (Acute toxicity to Daphnia magna, EC50 <10 mg/l (dry weight of the substance)
- Not toxic to aquatic algae within the classification limits (Toxicity to Pseudokirchneriella subcapitata, 100 > EC50 > 10 mg/l (dwt)
Additionally, the need for classification according to the CLP rules was evaluated based on the expected maximum concentration of the only identified main ingredient reported in the White liquor typical composition (1.2), which holds a harmonized classification for aquatic hazard (sodium sulfide, EC 215-211-5).
The overall toxicity of White liquor is expected to be decreased relatively rapidly in the aquatic environment in the presence of oxygen (degradation rate of sulfides is comparable to readily biodegradable organic substances). Rapid oxidation of sulfides is predominantly an abiotic process, even if microbes are also capable of effectively oxidizing sulfides to elemental sulphur, sulfites and sulfates. As a conclusion White liquor (as a registered UVCB substance) can be regarded here as a readily (bio)degradable substance in ecotoxicological point of view. Regarding the Aquatic toxicity of white liquor, sulfides are known to be the main driver in promoting aquatic toxicity observed for White liquor. The tested sample contained 10 % sulfides equal to 24.4 % Na2S in dry solids.
Overall conclusion on environmental classification of White Liquor
Sulfide based specific concentration limits have been derived for environmental Classification of White liquor dry solids. The limits have been set on the basis of combination of test results for white liquor, bridging principles applying test result data for Green liquor and applying summation rules of the CLP regulation.
White liquor dry solids is classified to Aquatic Acute 1 category. Classification applies to those substances that contain > 10 % sulfides (S2-) in dry solids.
White liquor does not meet the criteria for classification for any of the Aquatic Chronic categories.
White liquor does not meet the criteria for classification for other hazard classes i.e. hazard to the ozone layer.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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