Calcium acid methanearsonate-Pesticide database

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Calcium acid methanearsonate

(Also known as: methanearsonic acid, calcium salt ; CAMSA; CAMA; calcium hydrogen methanearsonate )

Calcium acid methanearsonate is an obsolete herbicdie 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.

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	Ecotoxicity Moderate alert: Bees acute contact ecotoxicity: Moderate Warning: Significant data are missing	Human health High alert: Neurotoxicant

GENERAL INFORMATION

An arsenical herbicide used for post-emergence weed control mainly on turf

Example pests controlled

Crabgrass; Stiltgrass; Barnyardgrass; Goosegrass

Example applications

Turfgrass; Ornamental turf; Turf grown for sod; Golf courses and sports turf; Cotton; Roads and rights-of-way

Efficacy & activity

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

UK regulatory status

UK COPR regulatory status

Date COPR inclusion expires

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Dossier rapporteur/co-rapporteur

Date EC 1107/2009 inclusion expires

EU Candidate for substitution (CfS)

Listed in EU database

Approved for use (✓) under EC 1107/2009 in the following EU Member States

ATAustria	BEBelgium	BGBulgaria	CYCyprus	CZCzech Republic	DEGermany	DKDenmark	EEEstonia	ELGreece

ESSpain	FIFinland	FRFrance	HRCroatia	HUHungary	IEIreland	ITItaly	LTLithuania	LULuxembourg

LVLatvia	MTMalta	NLNetherlands	PLPoland	PTPortugal	RORomania	SESweden	SISlovenia	SKSlovakia

Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries

ISIceland	NONorway

Additional information

Chemical structure

Chemical formula

C₂H₈As₂CaO₆

Canonical SMILES

C[As](=O)([O-])[O-].C[As](=O)([O-])[O-].[Ca+2]

Isomeric SMILES

International Chemical Identifier key (InChIKey)

PKOMXLRKGNITKG-UHFFFAOYSA-J

International Chemical Identifier (InChI)

InChI=1S/2CH5AsO3.Ca/c2*1-2(3,4)5;/h2*1H3,(H2,3,4,5);/q;;+2/p-4

2D structure diagram/image available?

Substance groups

Arsenical herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Interferes with ATP production and cell division

US EPA chemical code

CLP index number

PIN (Preferred Identification Name)

calcium methyl-dioxido-oxo-γ5-arsane

Other status information

PAN Bad Actor Chemical; Possible groundwater contaminant

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Fungicide Resistance Classification (FRAC)

Examples of recorded resistance

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

Source; quality score; and other information

Solubility - In water at 20 °C (mg l⁻¹)

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source

Octanol-water partition coefficient at pH 7, 20 °C

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

Fat solubility of residues

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)

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Surface tension (mN m⁻¹)

Source; quality score; and other information

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source

DT₅₀ (lab at 20 °C)

Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Best available data

Dissipation rate RL₅₀ on plant matrix

Dissipation rate RL₅₀ on and in plant matrix

Aqueous photolysis DT₅₀ (days) at pH 7

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Source; quality score; and other information

Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source

Slightly mobile

Notes and range

Best available data

Notes and range

Source; quality score; and other information

GUS leaching potential index

Transition state

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Potential for particle bound transport index

Potential for loss via drain flow

Slightly mobile

Bio-concentration factor

BCF (l kg⁻¹)

F4 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 )
4 = Verified data

Based on LogP < 3

CT₅₀ (days)

Known metabolites

None

Terrestrial ecotoxicology

Source; quality score; and other information

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

F4 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 )
4 = Verified data

Mammals - Short term dietary NOEL

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

F4 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 )
4 = Verified data

Colinus virginianus

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

F4 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 )
4 = Verified data

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)

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

Source; quality score; and other information

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Fish - Chronic 21 day NOEC (mg l⁻¹)

Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻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

HUMAN HEALTH AND PROTECTION

Source; quality score; and other information

Threshold of Toxicological Concern (Cramer Class)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

F4 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 )
4 = Verified data

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

F4 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 )
4 = Verified data

Mammals - Inhalation LC₅₀ (mg l⁻¹)

F4 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 )
4 = Verified data

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 500 mg kg⁻¹

V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

EU MRL pesticide database

GB MRL Register

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Specific human health issues

Endocrine disruptor

?Possibly, status not identified

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

?Possibly, status not identified

XNo, known not to cause a problem

✓Yes, known to cause a problem

Respiratory tract irritant

Skin sensitiser

✓Yes, known to cause a problem

✓Yes, known to cause a problem

✓Yes, known to cause a problem

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

Value and interpretation

When heated to decomposition it emits toxic fumes of Arsenic
Fire extinguishing agents include dry powder, water, sand, carbon dioxide and foam.

CLP classification 2013

WHO Classification

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

calcium acid methanearsonate

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