(Also known as: methanearsonic acid, calcium salt ; CAMSA; CAMA; calcium hydrogen methanearsonate )
SUMMARY
Calcium acid methanearsonate is an obsolete herbicide that was used for post-emergence weed control mainly on turf. It is highly soluble in water and is expected to be persistent in soil systems. It has a low avian toxicity but moderately toxic to honeybees. It has a low mammalian toxicity if ingested but is a probably neurotoxin.
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.
Environmental fate
Ecotoxicity
Human health
Environmental fate High alert: Persistent; Potential for particle bound transport: High
PAN Bad Actor Chemical; Possible groundwater contaminant
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Class (HRAC MoA class)
Not known
Herbicide Resistance Class (WSSA MoA class)
Not known
Insecticide Resistance Class (IRAC MoA class)
Not applicable
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
-
Physical state
Solid
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
Solaris Group, USA
Example products using this active
Ortho Crabgrass killer
Formulation and application details
Usually formulated as liquid concentrates and ready-to-use solutions
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
860000
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
-
-
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
205.8
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Octanol-water partition coefficient at pH 7, 20 °C
P
6.61 X 10-02
Calculated
-
Log P
-1.18
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
-
-
-
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)
269
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Persistent
DT₅₀ (lab at 20 °C)
269
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Persistent
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Best available data
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)
37
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Slightly mobile
Koc (mL g⁻¹)
1680
Notes and range
Best available data
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
1.88
Calculated
Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
7.11 X 10-02
Calculated
-
Note
-
Potential for particle bound transport index
High
Calculated
-
Potential for loss via drain flow
Slightly mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
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
?Possibly, status not identified
Reproduction / development effects
Acetyl cholinesterase inhibitor
Neurotoxicant
?Possibly, status not identified
XNo, known not to cause a problem
✓Yes, known to cause a problem
Respiratory tract irritant
Skin irritant
Skin sensitiser
✓Yes, known to cause a problem
✓Yes, known to cause a problem
No data found
Eye irritant
Phototoxicant
✓Yes, known to cause a problem
No data found
General human health issues
Highly toxic Liver, kidney, renal and cardiovascular system toxicant May cause anemia, leucopenia and thrombocytopenia May damage muscular coordination
Handling issues
Property
Value and interpretation
General
When heated to decomposition it emits toxic fumes of Arsenic Fire extinguishing agents include dry powder, water, sand, carbon dioxide and foam.
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
Environmental fate
Ecotoxicity
Warning:
