Calcium hydroxide is an inorganic salt that has a range of pesticidal functions but these tend not to be agriculturally focused. The substance has a high aqueous solubility but is not volatile and is not considered to be problematic for environmental quality. No significant human health issues have been identified. Although there is a data gap for ecotoxicology data calcium hydroxide is not likely to be a serious issue.
Data alerts
The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.
Insecticide, Herbicide, Fungicide, Other substance
Other bioactivity & uses
Microbiocide
Substance groups
Inorganic compound
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
Non-selective, phytotoxic
CAS RN
1305-62-0
EC number
215-137-3
CIPAC number
None allocated
US EPA chemical code
075601
PubChem CID
6093208
CLP index number
No data found
Molecular mass
74.09
PIN (Preferred Identification Name)
-
IUPAC name
calcium hydroxide
CAS name
calcium hydroxide
Other status information
Approved via EU & UK 'Basic substance' legislation (Article 28 of Regulation (EC) No 1107/2009)
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Class (HRAC MoA class)
None allocated
Herbicide Resistance Class (WSSA MoA class)
None allocated
Insecticide Resistance Class (IRAC MoA class)
Not known
Fungicide Resistance Class (FRAC MOA class)
NC
Examples of recorded resistance
-
Physical state
White solid
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
-
Example products using this active
-
Formulation and application details
-
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
1950
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
590
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
-
-
-
Log P
-
-
-
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
2.24
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data
-
Dissociation constant pKa) at 25 °C
-
-
-
-
Vapour pressure at 20 °C (mPa)
-
-
-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
-
-
-
Volatilisation as max % of applied dose lost
From plant surface
-
-
-
From soil surface
-
-
-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹
-
-
-
Surface tension (mN m⁻¹)
-
-
-
Degradation
Property
Value
Source; quality score; and other information
Interpretation
General biodegradability
-
Soil degradation (days) (aerobic)
DT₅₀ (typical)
0.1
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Non-persistent
DT₅₀ (lab at 20 °C)
0.1
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Non-persistent
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Rapidly disperses in soil
Dissipation rate RL₅₀ (days) on plant matrix
Value
-
-
-
Note
-
Dissipation rate RL₅₀ (days) on and in plant matrix
Value
-
-
-
Note
-
Aqueous photolysis DT₅₀ (days) at pH 7
Value
-
-
-
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
-
-
-
Note
-
Water-sediment DT₅₀ (days)
-
-
-
Water phase only DT₅₀ (days)
-
-
-
Sediment phase only DT₅₀ (days)
-
-
-
Air degradation
As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.
Decay in stored produce DT₅₀
-
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd (mL g⁻¹)
-
-
-
Koc (mL g⁻¹)
-
Notes and range
-
Freundlich
Kf (mL g⁻¹)
-
-
-
Kfoc (mL g⁻¹)
-
1/n
-
Notes and range
-
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
-
-
-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
Cannot be calculated
-
-
Note
-
Potential for particle bound transport index
Low
Calculated
-
Potential for loss via drain flow
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
Low risk
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Low risk
CT₅₀ (days)
Not available
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
7340
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Chronic
-
-
-
Notes
-
Bumblebees (Bombus spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
-
Mason bees (Osmia spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Other bee species (1)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
-
-
-
Mode of exposure
-
Other bee species (2)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
-
-
-
Mode of exposure
-
Beneficial insects (Ladybirds)
-
-
-
Beneficial insects (Lacewings)
-
-
-
Beneficial insects (Parasitic wasps)
-
-
-
Beneficial insects (Predatory mites)
-
-
-
Beneficial insects (Ground beetles)
-
-
-
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
240
F2 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 2 = Unverified data of unknown source
Gambusia affinis
Low
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
-
-
-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)
-
-
-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
-
-
-
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
-
-
-
Mesocosm study data
NOEAEC mg l⁻¹
-
-
-
NOEAEC mg l⁻¹
-
-
-
Marine bivalves
-
-
-
HUMAN HEALTH AND PROTECTION
General
Property
Value
Source; quality score; and other information
Interpretation
Threshold of Toxicological Concern (Cramer Class)
High (class III)
-
-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
7340
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here ) 4 = Verified data
Rat
Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
-
-
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
-
-
-
Other Mammal toxicity endpoints
-
-
-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
None allocated
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
None allocated
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
Dermal penetration studies (%)
-
-
-
Dangerous Substances Directive 76/464
-
-
-
Exposure Routes
Public
-
Occupational
-
MRLs
European
EU MRL pesticide database 
Great Britain
GB MRL Register 
Notes
-
Drinking Water Standards
-
-
-
Drinking Water MAC (μg l⁻¹)
-
-
-
Mammalian dose elimination route and rate
-
-
-
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
XNo, known not to cause a problem
A0 A = Chromosome aberration (EFSA database) 0 = No data
;
B0 B = DNA damage/repair (EFSA database) 0 = No data
;
C0 C = Gene mutation (EFSA database) 0 = No data
;
D0 D = Genome mutation (EFSA database) 0 = No data
;
E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data
No data found
Reproduction / development effects
Acetyl cholinesterase inhibitor
Neurotoxicant
No data found
XNo, known not to cause a problem
XNo, known not to cause a problem
Respiratory tract irritant
Skin irritant
Skin sensitiser
✓Yes, known to cause a problem
✓Yes, known to cause a problem
XNo, known not to cause a problem
Eye irritant
Phototoxicant
 
✓Yes, known to cause a problem
No data found
 
General human health issues
Caustic irritant
Handling issues
Property
Value and interpretation
General
Corrosive Prevent generation of dust IMDG Transport Hazard Class 8
Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242