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EC number: 947-964-7
CAS number: -
Table 1. Classes of compounds
Carboxylic acid esters
They hydrolyse by base-promoted reactions at pH 5-6.
Less hydrolytically reactive than esters. Typical half-lives under environmental conditions – hundreds to thousands of years.
In fresh waters they hydrolyse to the corresponding alcohol. For polyhalogenated alkanes, a 1,2 or 1,1 elimination is the most general elimination reaction.
Hydrolyses occurs by neutral, acid- or base- mediated reactions. Acid and neutral processes generally dominate over the range of environmental pH.
They undergo acid and alkaline hydrolysis to the corresponding amide first, and then to carboxylic acid and ammonia.
They can undergo hydrolysis depending on the substituents on the N atom. When an alkyl substituent is present on the N atom, hydrolysis is much slower.
The hydrolysis reaction is highly pH dependend. The principal cleavage occurs at the sulfonylurea bridge.
Hydrolysis can occur by direct nucleophilic attack at the P atom, without the formation of a pentavalent intermediate.
Does not hydrolyse – no hydrolysable functional group present.
Does not hydrolyse; however, it may undergo other abiotic transformation processes.
Resistant to hydrolysis. Hydroxide or hydronium is required to facilitate hydrolysis. Hydrolysis proceeds through the intermediate amide to the final product, acetic acid.
Undergoes a rapid addition of water across the double bond (Michael addition) to yield 3-hydroxy-1-propanal.
An intermediate in the hydrolysis of acrylonitrile to acrylic acid. At high concentrations of hydroxide, acrylamide polymerizes. The end product of hydrolysis is acrylic acid.
Hydrolyses to acrylic acid through the intermediate acrylamide.
All aldrin chlorine atoms are either protected from nucleophilic attack (bridgehead carbon) or are non-reactive (on the sp2 carbon). Aldrin has been designated the assignment of NLFG.
The sulfite bond in Aramite is very susceptible to hydrolysis. Initial hydrolysis of Aramite proceeds with cleavage of either of two sulfoxide bonds. This initial hydrolysis yields four products, two alcohols and two hydrogen sulfites.
Hydrolysis proceeds through nucleophilic substitution of chlorine by H2O. The halohydrin formed by this displacement is unstable and reacts further to yield benzoic acid.
Hydrolysis occurs through nucleophilic displacement of chlorine by H2O. Hydrolysis is not mediated by hydroxide.
Hydrolysis occurs through nucleophilic displacement of chlorine with H2O. The monochloroether formed by this reaction will undergo a second substitution by H2O to yieldbis(2-hydroxyethyl)ether and intramolecular displacement of chlorine to yield dioxane.
Instable with half-life of minutes.
Hydrolyses by nucleophilic attack of HO-at the ester carbonyl group to give 2-ethylhexyl hydrogen phthalate and 2-ethylhexanol. The monoester will undergo further base-mediated hydrolysis to o-phthalic acid and 2-ethylhexanol.
Hydrolysis occurs initially by proton abstraction followed by formation of the carbene, which reacts with HO-to form carbon monoxide and the mineral acids.
Hydrolysis proceeds through nucleophilic substitution of bromine by H2O to yield methanol and hydrobromic acid.
Butyl benzyl phthalate
Butyl benzyl phthalate is a mixed ester formed by condensation of phthalic acid with two different alcohols. The hydrolysis mechanism is the same as described forbis(2-ethyl-hexyl)phthalate (No. 25) with the two resulting monoesters undergoing further hydrolysis to o-phthalic acid and the corresponding alcohols.
Hydrolysis occurs by nucleophilic attack of HO-. The initial hydrolysis product is carbonyl sulfide, which reacts further with H2O or HO-to give carbon dioxide and hydrogen sulfide.
Hydrolysis occurs by reaction with H2O to yield carbon dioxide and the mineral acid.
Hydrolysis proceeds by nucleophilic substitution of chlorine by HO-to give 2,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methano-1H-indene, which will not be susceptible to further hydrolysis.
Does not hydrolyse to any reasonable extent; however, it may undergo other abiotic transformation processes.
Does not hydrolyze to any reasonable extent; however, it may undergo other abiotic transformation processes.
Hydrolysis is analogous to the phthalate esters and proceeds through nucleophilic attack of HO-at the ester carbonyl. The resulting acid is stable in the ionic form, but the protonated form that would exist at acidic pH values will decarboxylate with concurrent oxidation to yield carbon dioxide andp,p'-dichlorobenzophenone.
Hydrolysis occurs initially by proton abstraction followed by formation of the carbene, which reacts with HO-to form carbon monoxide and the mineral acid.
Chloromethane has a negative boiling point and exists in a gaseous state at room temperature. Its hydrolysis pathway has not been addressed.
Neutral hydrolysis occurs through the formation of the allylic carbonium ion, which reacts with H2O to give 3-hydroxypropene and the mineral acid.
Hydrolyses by nucleophilic attack of H2O resulting in carbon dioxide and ammonia.
Does not hydrolyse to any reasonable extent.
The reaction of DDD occurs by the elimination of chlorine (dehydrochlorination) to give 2,2-bis(4-chlorophenyl)-1-chloroethene (DDMU). This process will occur by reaction with either H2O or HO-.
The reaction ofp.p’-DDT occurs in a manner analogous to DDD. The reaction products resulting from dehydrochlorination are DDE and the mineral acid.
Hydrolyses by nucleophilic attack of H2O and HO-at the carbonyl group resulting in the formation of diisopropylamine andcis- andtrans-2,3-dichloro-2-propene-1-thiol.
1,2-Dibromo-3-chloropropane is subject to both neutral and base-mediated hydrolysis. Neutral hydrolysis occurs initially by nucleophilic displacement of either chlorine or bromine.
Dibromomethane should not hydrolyse to any reasonable extent. QSAR model computations have indicated that the half-life of this halogenated methane is several thousand years.
Does not hydrolyse to any reasonable extent, however, it may undergo other abiotic transformation processes.
Dichlorodifluoromethane has a negative boiling point and exists in a gaseous state at room temperature. Its hydrolysis pathway has not been addressed.
The reaction of 1,1-dichloroethane occurs by both nucleophilic substitution and dehydrochlorination. The reaction products resulting from nucleophilic substitution by H2O and HO-are acetaldehyde and HCl, whereas dehydrochlorination gives vinyl chloride and the mineral acid.
The reaction of 1,2-dichloroethane by H2O and HO-occurs by both nucleophilic substitution and dehydrochlorination. Hydrolysis by nucleophilic substitution will lead to the formation of 2-chloroethanol and HCl, whereas dehydrochlorination results in vinyl chloride and the mineral acid. 2-Chloroethanol will react further producing ethylene oxide, which will hydrolyse by reaction with H2O to yield ethylene glycol.
Hydrolysis of dichloromethane occurs by nucleophilic substitution with H2O (neutral hydrolysis) resulting in the displacement of chlorine with HO-. The resulting chlorohydrin is a transient intermediate that immediately loses chlorine to yield formaldehyde, the final hydrolysis product.
The reaction of 1,2-dichloropropane with H2O or HO-will proceed through competing reaction pathways (nucleophilic substitution and dehydrohalogenation). Nucleophilic substitution will occur at the primary carbon resulting in the formation of 2-chloropropanol. This intermediate will degrade by intramolecular nucleophilic displacement of the chlorine atom by the adjacent hydroxyl group resulting in the formation of propylene oxide. Propylene oxide will undergo predominantly neutral hydrolysis to give 1,2-dihydroxypropane. Base-mediated elimination of chlorine will result in the formation of 1-chloro-l-propene, which will be stable to further hydrolysis.
Hydrolysis will occur by reaction with H2O through nucleophilic substitution resulting in the formation of 3-chloro-2-propene-1-ol.
Hydrolysis will occur through nucleophilic substitution with H2O at the epoxide moiety resulting in the formation of the diol. The diol will be stable to further hydrolysis.
The base-mediated hydrolysis will initially result in formation of the monoester, which will undergo further hydrolysis to o-phthalic acid. The hydrolysis of the monoester will occur at a rate approximately half that of the parent compound.
Hydrolysis may occur through either reaction with H2O (neutral hydrolysis) or reaction with HO (base-mediated hydrolysis).
Hydrolyses by nucleophilic attack of HO-at the ester carbonyl group resulting in methyl hydrogen phthalate and methanol, which can undergo further base-mediated hydrolysis to o-phthalic acid.
The reaction pathway for the hydrolysis of di-n-butyl phthalate is identical to that described previously for dimethyl phthalate (#81).
The reaction pathway for the hydrolysis of di-n-octyl phthalate is identical to that described previously for dimethyl phthalate (#81).
Does not hydrolyse to any reasonable extent; however, they may undergo other abiotic transformation processes.
Neutral hydrolysis can occur at two sites resulting in the formation of phosphorus diesters, which will hydrolyse through the phosphate monoester to eventually give phosphoric acid and hydrogen sulfide. As with dimethoate, base-mediated hydrolysis will occur by nucleophilic attack of HO-at the central phosphorus atom resulting in 2-thioethylethylthioether and O,O-diethylphosphorothioic acid, which will hydrolyse further to phosphoric acid and hydrogen sulfide.
Endosulfan, which is a mixture of thealpha(Endosulfan I) andbeta(Endosulfan II) isomers, will hydrolyse by nucleophilic attack of H2O or HO-at the sulfur atom resulting in the alpha and beta isomers of endosulfan diol. The ratio of thealphato thebetaisomers of endosulfan diol will reflect the ratio of Endosulfan I to Endosulfan II in the parent compound.
Hydrolysis will proceed by nucleophilic attack of H2O at the epoxide moiety resulting in the formation of endrin diol, which will be stable to further hydrolysis.
Hydrolysis will occur initially by attack of H2O at the epoxide moiety resulting in the formation of 1-chloro-2,3-dihydroxypropane. Subsequently, loss of chlorine will occur through the intramolecular attack of HO-on the adjacent carbon to give 1-hydroxy-2,3-propylene oxide, which will undergo further hydrolysis by attack of H2O at the epoxide moiety to give glycerol.
Hydrolysis will occur by acyl-oxygen bond cleavage by H2O and acid catalysis and base mediation resulting in the formation of acetic acid and ethanol.
Hydrolysis will occur by the base-mediated cleavage of the acyl-oxygen bond resulting in methacrylic acid and ethanol.
Hydrolysis will occur in a manner analogous to the hydrolysis of carboxylic acid esters. Nucleophilic attack of H2O at the carbon results in the formation of methylsulfonic acid and ethanol.
The reaction of ethylene dibromide proceeds by either nucleophilic substitution or dehydrohalogenation.
The reaction pathways for the hydrolysis of famphur are similar to the organophosphorus esters. Both base and neutral hydrolysis can occur by nucleophilic attack at the phosphorus atom resulting in the formation of phosphorous diesters, which will hydrolyse through the phosphate monoester eventually to result in phosphoric acid and hydrogen sulfide, andp-(N,N-dimethylsulfamoyl)phenol.
Hydrolysis will occur by nucleophilic substitution of H2O at the allylic-carbon-bearing chlorine resulting in the formation of 1-hydroxychlordene, which will be stable to further hydrolysis.
Heptachlor will hydrolyse by nucleophilic attack of H2O at the epoxide moiety resulting in heptachlor diol. Further hydrolysis of the diol can occur by nucleophilic substitution of H2O at the chlorine-bearing carbon adjacent to the hydroxyl groups. The resulting triol will be stable to further hydrolysis.
The reaction ofalpha-HCH occurs bytrans-dehydrochlorination of the axial chlorines resulting in the intermediate 1,3,4,5,6-pentachlorocyclohexene. This cylcohexene will react further with either H2O or HO-through sequential dehydrochlorination steps to give a mixture of the regioisomers, 1,2,3-trichlorobenzene and 1,2,4-trichlorobenzene.
Does not hydrolyse to any reasonable extent (NLFG). The six equatorial chlorines do not permit initial trans-dehydrochlorination to yield the intermediate pentachlorocyclohexene as occurs in thealpha- (#122.) andgamma-isomers (#132).
Hydrolysis results in the formation of 1,1-dihydroxy-tetrachlorocylcopentadiene, which is an unstable product. Its degradation leads to the formation of polymers.
The reaction pathway for the hydrolysis ofgamma-HCH (lindane) is identical to that described foralpha-HCH (#122).
Hydrolysis will occur by the acid-catalysed or base-mediated hydrolysis of the nitrile moiety to give methacrylic acid and ammonia.
The products formed during aqueous hydrolysis of methoxychlor are influenced by the pH of the system. Above pH 10, 2,2-bis(p-methoxyphenyl)-1-1-dichloroethylene (DMDE) is the only reported product. Below pH 10 a second product, anisoin, is observed. Anisoin is the major product formed by hydrolysis when the system is below pH 8; however, it is unstable and will oxidize to anisil. Hydrolysis is not an important pathway in further degradation of DMDE and anisil.
Methyl ethyl ketone
Methyl isobutyl ketone
Hydrolysis proceeds through nucleophilic attack by HO-at the ester carbonyl to yield methacrylic acid and methanol.
Hydrolysis may occur through either reaction with H2O (neutral hydrolysis) or reaction with HO-(base-mediated hydrolysis). Nucleophilic substitution by H2O occurs in sequence at the two methoxy carbons to yield O-methyl-O-(p-nitrophenyl)-phosphorothioic acid (diester) and O-(p-nitrophenyl)phosphorothioic acid (monoester), respectively. Hydroxide-ion-mediated hydrolysis of methyl parathion proceeds through initial attack of the hydroxide ion on the phosphorus atom with displacement of the p-nitrophenylate ion. The phosphorothioic acid generated in each hydrolytic pathway will eventually degrade to phosphoric acid and hydrogen sulfide.
Octamethyl pyrophosphoramide (OMPP)
Hydrolysis proceeds through cleavage of the P-O-P bond. OMPP is stable to attack by the hydroxide ion and the neutral water molecule, but is degraded under acidic conditions.
Parathion is the ethyl analog of methyl parathion. The products formed and mechanisms of hydrolysis parallel those of methyl parathion (#141) but hydrolysis proceeds at a slower rate typical for triethyl phosphates compared to trimethyl phosphates.
In an experiment, no disappearance of PCNB was observed after 33 days at pH 11 and 85 °C. PCNB has, therefore, been designated as NLFG.
The three isomers don’t hydrolyse; however, it may undergo other abiotic transformation processes.
Phorate is an analog of disulfoton. The products formed and mechanisms of hydrolysis parallel those of disulfoton. Phorate has a neutral hydrolysis rate of approximately 30 times that of disulfoton (#96).
Hydrolyses to o-phthalic acid in water. The hydrolysis occurs through nucleophilic attack of H2O at a carbonyl carbon.
TheN-substituted amide bond in pronamide, formed by reaction of a carboxylic acid and primary amine, is more resistant to hydrolysis than similar bonds formed with carboxylic acids and alcohols.
The hydrolysis pathway will proceed through competing pathways (nucleophilic substitution and dehydrohalogenation). Nucleophilic substitution will occur at the monochlorinated carbon with formation of trichloroethanol. Degradation of trichloroethanol will continue to yield glycolic acid (hydroxyacetic acid). Base-mediated elimination of chlorine from 1,1,1,2-tetrachloroethane will result in formation of 1,1,2-trichloroethylene.
Hydrolyses by the base-mediated elimination of chlorine to 1,1,2-trichloroethylene. This quantitative conversion occurs in the pH range of 5-9.
The P-O-P bond is very labile to attack by hydroxide, even at concentrations of hydroxide present below pH 7. The resultingO,O-diethyl-phosphorothioic acid is hydrolysed to the final products phosphoric acid and ethanol.
It is a complex but reproducible mixture of chlorinated camphene (67-69% chlorine by weight). The mixture has been shown to contain at least 177 and up to 670 components. The degradation rate was determined by monitoring the loss of chlorine with time during hydrolysis rate studies.
Nucleophilic attack by H2O on the trichloro-substituted carbon yields acetic acid, while the hydroxide-ion-mediated elimination product is 1,1-dichloroethylene. The ratio of these products is pH dependent. Acetic acid is the major product at low values of pH, while the amount of 1,1-dichloroethylene, increases with increasing values of pH.
Hydrolysis will yield the substitution product, chloroacetaldehyde, and the base-mediated elimination product, 1,1-dichloroethylene. The most acidic hydrogen (dichloro-substituted carbon) is lost during elimination of chlorine to form 1,1-dichloroethylene rather than 1,2-dichloroethylene. The ratio of products will be determined by the pH of the system.
Does not hydrolyse to any reasonable extent based on other polyhalogenated methanes.
2-(2,4,5-Trichlorophenoxy)propionic acid (Silvex)
By analogy to 1,2-dibromo-3-chloropropane (#58), the ultimate products of aqueous degradation are 2-chloro-3-hydroxy-1-propene and glycerol. The route to the substitution product, glycerol, proceeds through intermediate haloalcohols and halohydrins. The amount of the elimination product, 2-chloro-3-hydroxy-1-propene, will increase with increase in hydroxide ion concentration.
Hydrolysis by nucleophilic attack of H2O on the C-O bond or hydroxide ion attack on phosphorus will yield the same products. The 2,3-dibromo-propanol can undergo hydroxide-ion-mediated elimination to yield 2-bromo-2-propen-1-ol or intramolecular displacement of bromine by the adjacent hydroxyl group to form epibromohydrin. The epibromohydrin is ultimately hydrolysed to the final product, glycerol. TheO,O-(2,3-dibromopropyl)phosphoric acid will hydrolyse further to yield phosphoric acid and 2,3-dibromopropanol.
organic functional groups are relatively or completely inert with
respect to hydrolysis. Other functional groups may hydrolyze under
1. Types of Organic Functional Groups That Are Generally Resistant to
Polycyclic aromatic hydrocarbons
Heterocyclic polycyclic aromatic hydrocarbons
Dieldrin/aldrin and related halogenated hydrocarbon pesticides
Aromatic nitro compounds
Multifunctional organic compounds in these categories may, of course, be
hydrolytically reactive if they contain a hydrolyzable functional group
in addition to the alcohol, acid, etc., functionality.
2. Types of Organic Functional Groups That are Potentially Susceptible
Phosphonic acid esters
Phosphoric acid esters
Sulfonic acid esters
Sulfuric acid esters
The substance has hydrolysis half-lifes at
25°C of above 1 year.
In accordance with REACH Annex XI
“General rules for adaptation of the standard testing regime set out in
annexes VII to X” section 1 “testing does not appear scientifically
necessary” point 1.1 “Use of existing data”, the study does not need to
be conducted as available data provide sufficient information. According
to literature data of Harris (1990), Kollig et al. (1993) and Boethling
& Mackay (2000) hydrolysis of the substance is not expected.
Furthermore, in accordance with In
accordance with REACH Annex XI “General rules for adaptation of the
standard testing regime set out in annexes VII to X” section 2 “testing
is technically not possible” the study cannot be conducted as due to the
high volatility of the substance it was not possible to establish a
suitable analytical method in aqueous media and buffer solution.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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