L-ascorbic acid

L-ascorbic acid	Last updated: 21/05/2026
(Also known as: Vitamin C; ascorbic acid; 3-oxo-1-gulofuranolactone)

Hazard alerts

The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.

PHT: Environmental fate	PHT: Ecotoxicity	PHT: Human health	Highly Hazardous Pesticide
	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate	Human health High alert: Genotoxic

GENERAL INFORMATION

Description

Substance with fungicide and bactericide action against a range of crop diseases

Example pests/issues controlled

Late blight (Phytophthora infestans); Wilts (fusarium spp.); Grey mold (Botrytis spp.)

Example applications

Potatoes; Tomatoes; Ornamentals

Efficacy & activity

Appearance and life cycle

Taxonomic classification

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Withdrawn

GB LERAP status

No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Netherlands

Date EC 1107/2009 inclusion expires

EU Candidate for substitution (CfS)

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

Chemical structure

Isomerism

Ascorbic acid exists as two enantiomers commonly referred to as L-ascorbic acide and D-ascorbic acid. The L-isomer is the more common.

Chemical formula

C₆H₈O₆

Canonical SMILES

C(C(C1C(=C(C(=O)O1)O)O)O)O

Isomeric SMILES

C([C@@H]([C@@H]1C(=C(C(=O)O1)O)O)O)O

International Chemical Identifier key (InChIKey)

CIWBSHSKHKDKBQ-JLAZNSOCSA-N

International Chemical Identifier (InChI)

InChI=1S/C6H8O6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10H,1H2/t2-,5+/m0/s1

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
L-ascorbic acid	-
L-ascorbic acid	-

General status

Biopesticide type

Fungicide; Other substance

Other bioactivity & uses

Bactericide; Biocide

Substance groups

Plant-derived substance

Minimum active substance purity

>990 g kg⁻¹

Known relevant impurities

EU dossier - methanol <3g kg⁻¹; heavy metals 0.01g kg⁻¹

Substance origin

Natural

Mode of action

Systemic, protective, stimulates the natural defence mechanisms and wound healing processes in plants

Substance source

A naturally occurring substance that can be isolated from synergistic vitamin C complexes found in living nutrient sources particularly citrus fruits, tomatoes and tomato juice, and potatoes

Uses

Crop protection

Farming system suitability

CAS RN

50-81-7

EC number

200-066-2

CIPAC number

774

US EPA chemical code

PubChem CID

Molecular mass (Da)

176.1

PIN (Preferred Identification Name)

IUPAC name

(5R)-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one

CAS name

Global Governance status: Listed (✓) under

UK Poisons List Order 1972	Rotterdam Convention	Montreal Protocol
XNo The Poisons List Order 1972	XNo Rotterdam Convention	XNo Montreal Protocol
Stockholm Convention	OSPAR	EU Water Framework Directive
XNo Stockholm Convention	XNo OSPAR	XNo EU Water Framework Directive

Relevant Environmental Water Quality Standards

Forever chemical

Highly Hazardous Pesticide (HHP)

Type I

Type II

Other status information

Some applications may be approevd under the GB Biocide Products Regulations

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Examples of recorded resistance

Physical state

White powder

Commercial

Property

Value

Availability status

Current

Introduction & key dates

18th Centuary, discovered; 2011, introduced as pesticide

Example manufacturers & suppliers of products using this active now or historically

Citrex Europe BV

Example products using this active

Formulation and application details

Usually supplied as a soluble liquid

Commercial production

L-ascorbic acid is produced commercially through a multi-step process that typically begins with glucose derived from corn starch. The most established method is the Reichstein process, which involves the hydrogenation of D-glucose to D-sorbitol, followed by microbial fermentation to L-sorbose. This is then chemically oxidised to form 2-keto-L-gulonic acid (2-KLG), which undergoes cyclization to yield L-ascorbic acid. More recently, a two-step fermentation method has gained popularity. This biotechnological approach bypasses some chemical steps, relying more on engineered microbes to convert sorbitol directly into 2-KLG, streamlining the process.

Impact on climate of production and use

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C at pH 7 (mg l⁻¹)

330000

High

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

Insoluble

Ether

Insoluble

Benzene

Insoluble

Chloroform

50000

Propylene glycol

Melting point (°C)

190

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

190

Flashpoint (°C)

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

1.32 X 10^-02

Calculated

Log P

-1.88

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

2.19 X 10^-02

Low volatility

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

1.16 X 10^-08

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

pH 6.4: max @ 265nm
pH 2: max @ 245nm

Surface tension (mN m⁻¹)

Not surface active

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Soil mineralisation

Aerobic (at 20 °C)

Anaerobic (at 20 °C)

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)

Fast

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

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Known soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

ascorbate-2-sulphate

Human

oxalic acid

Human

dehydroascorbic acid

Human

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

11900

Rat

Low

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

> 250

Gallus domesticus NOEL

Moderate

Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)

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

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

> 1000

Expert judgement

Low

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

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

> 600

24 plant species tested

Seedling emergence ER₅₀ (g ha⁻¹)

> 600

24 plant species tested

Honeybees (Apis spp.)

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

> 4.5

Apis mellifera

Moderate

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

> 15.9

Apis mellifera

Moderate

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) as Mortality LR₅₀ g ha⁻¹, Std lab test

> 0.7

Aphidius rhopalosiphi

Moderate

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹, Std lab test

9.1

Typhlodromus pyri

Moderate

Beneficial insects (Ground beetles) as Mortality LR₅₀ g ha⁻¹, Extended lab study

> 17

Poecilus cupreus

Moderate

Beneficial insects (Butterflies)

Contact

Notes

Oral

Notes

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 2000

Unknown species

Low

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

2000

Oreochromis niloticus

Low

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

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

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

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves – Acute EC₅₀, development (mg l⁻¹)

4.40

Crassostrea gigas

Regulatory Threshold Levels (RTLs)

Note: These RTLs have been calculated using the regulatory approach used in the European Union and based on ecotoxocity values in the PPDB.

Species group

RTL

Notes

Mammals

1190

Worst case of acute and chronic mammals

Birds

Worst case of acute and chronic birds

Soil organisms

100

Worst case of acute and chronic earthworms

Terrestrial plants

120

Worst case of non-target plants vegetative vigour and seedling emergence

Pollinators

0.09

Worst case of contact and oral honeybees

Arthropods

0.35

Worst case of parasitic wasps and predatory mites

Fish

Worst case of temperate acute and chronic fish

Aquatic invertebrates

No data

No data for temperate acute and chronic aquatic invertebrates

Aquatic plants

No data

No data for free-floating plants, rooted plants, acute and chronic algae

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Low (class I)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

11900

Rat

Low

Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)

Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Intravenous LD₅₀ = 518 mg kg⁻¹

Mouse

Subcutaneous LD₅₀ = 10000 mg kg⁻¹

Rat

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

None allocated

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

None allocated

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

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

None allocated

Dermal penetration studies (%)

100

Dangerous Substances Directive 76/464

Exposure Routes

Public

Considered safe

Occupational

Considered safe

Mammalian dose elimination route and rate

Readily absorbed and excreted mainly in the urine in humans and via the lungs in rats and guinea pigs

Health issues

Specific human health issues (hazard-based)

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Excessive consumption may cause diarrhoea and behavioural effects

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H315, H318, H319

WHO Classification

Not listed

UN Number

Not regulated

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

L-ascorbic acid

French

acide ascorbique

German

Danish

Italian

acidum ascorbicum

Spanish

acido ascorbico

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	21/05/2026
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

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