Dalapon-sodium	Last updated: 15/01/2023
(Also known as: dalapon; proprop; DPA)

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SUMMARY

Dalapon sodium is a selective herbicide. It is highly soluble in water and volatile. Based on its chemical properties it has a tendency to leach to groundwater. Data suggests it is moderately persistent in soil systems and can be persistent in some water systems. It is relatively non-toxic to mammals and has a low potential for bioaccumulation. Dalapon sodium is a recognised irritant. It has a moderate toxicity to most aquatic organisms and honeybees but is less harmful to birds and earthworms.

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: GUS: High leachability	Ecotoxicity Moderate alert: Daphnia acute ecotoxicity: Moderate; Bees acute unknown ecotoxicity: Moderate	Human health Low alert Warning: Significant data are missing

GENERAL INFORMATION

Description	A herbicide used to control annual and perennial grasses including couch
Example pests controlled	Bluegrass; Crabgrass; Quackgrass; Bermudagrass Johnsssongrass; Cattails; Rushes; Barnyardgrass; Couch
Example applications	Cotton; Fruit including currants, plums, apricots, cherries, citrus; Potatoes; Sugarcane; Carrots; Alfalfa; Asparagus; Flax; Lucerne; Non-crop situations including domestic houses, commerical and industrial sites
Efficacy & activity	-
Availability status	Current
Introduction & key dates	1954, first year of public use

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	Expired
UK LERAP status	No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
Date EC 1107/2009 inclusion expires	Expired
EU Candidate for substitution (CfS)	Not applicable
Listed in EU database	Yes
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

Also used in	Australia

Chemical structure

Isomerism	None
Chemical formula	C₃H₃Cl₂NaO₂
Canonical SMILES	CC(C(=O)[O-])(Cl)Cl.[Na+]
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	PDEFQWNXOUGDJR-UHFFFAOYSA-M
International Chemical Identifier (InChI)	InChI=1S/C3H4Cl2O2.Na/c1-3(4,5)2(6)7;/h1H3,(H,6,7);/q;+1/p-1
2D structure diagram/image available?	Yes

General status

Pesticide type	Herbicide
Substance groups	Organochloride herbicide; Carboxylic acid herbicide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Selective, systemic absorbed through leaves and roots. Inhibition of lipid synthesis.
CAS RN	127-20-8
EC number	204-828-5
CIPAC number	52
US EPA chemical code	028902
PubChem CID	517058
CLP index number	607-162-00-7
Molecular mass	164.95
PIN (Preferred Identification Name)	sodium 2,2-dichloropropanoate
IUPAC name	sodium 2,2-dichloropropionate
CAS name	sodium 2,2-dichloropropionate
Other status information	-
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	Z
Herbicide Resistance Classification (WSSA)	0
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	Pale-coloured powder
Related substances & organisms	dalapon dalapon-calcium dalapon-magnesium

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Shell Dow Chemicals BASF Diamond Shamrock
Example products using this active	Radapon Dowpon basinex Revenge Alatex Ded-Weed
Formulation and application details	Usually supplied as a water-soluble powder

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		629000	K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data	High
Solubility - In organic solvents at 20 °C (mg l⁻¹)		110000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Ethanol	-
		369000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Methanol	-
		3250	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
		20	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Benzene	-
Melting point (°C)		166.5	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Decomposes	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	6.92 X 1000	Calculated	-
	Log P	0.84	K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here ) 4 = Verified data	Low
Fat solubility of residues	Solubility	Likely to be soluble	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
	Data type	Based on chemical group	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
Density (g ml⁻¹)		1.74	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		1.79	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
		Strong acid
Vapour pressure at 20 °C (mPa)		0.017	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low volatility
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)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT₅₀ (typical)	30	W2 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 2 = Unverified data of unknown source	Moderately persistent
	DT₅₀ (lab at 20 °C)	30	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source	Moderately persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Best available data
Dissipation rate RL₅₀ on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ 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	Stable	W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 4 = Verified data	Stable
	Note	Temperature sensitive, slow at 25 °C but quite rapid at 50 °C
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	DW3 DW = Don Wauchope personal database for Pka data: Wauchope, R. D. and Edwards, J. Dissociation constants for pesticide active ingredients: a database and comparison with predicted values. Dataset is no longer available. 3 = Unverified data of known source	Very mobile
	Koc	1
	Notes and range	Other sources: 2.34-151.4 mL g⁻¹ (R3)
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		5.91	Calculated	High leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	2.86 X 1000	Calculated	-
	Note	-
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		-	-	-
Bio-concentration factor	BCF (l kg⁻¹)	2.5	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data	Low potential
	CT₅₀ (days)	Not available		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
dalapon	Major fraction	-	-

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		9330	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	Low
Mammals - Short term dietary NOEL	(mg kg⁻¹)	15	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 year	High
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		5660	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Gallus domesticus	Low
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		1058	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Soil micro-organisms		-	-	-
Collembola	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)	-	-	-
	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)	> 50	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Moderate
	Chronic	-	-	-
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
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		> 100	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Oncorhynchus mykiss	Low
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		6	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source Unknown species	Moderate
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)		20	W2 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 2 = Unverified data of unknown source Unknown species	Low
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-

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)		9330	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
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	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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem No data found Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓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		Possible kidney toxicant

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H315, H318 Environment: H412
WHO Classification	U (Unlikely to present an acute hazard)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	dalapon-sodium
French	dalapon sodium
German	Dalapon natrium
Danish	dalapon natrium
Italian	dalapon sodio
Spanish	dalapon sodio
Greek	-
Polish	dalapon sodowy
Swedish	-
Hungarian	-
Dutch	dalapon natrium
Norwegian	-

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Record last updated:	15/01/2023
Contact:	aeru@herts.ac.uk
Please cite as:	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