Mucochloric Acid

H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H317 (94.7%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (71.3%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H341 (72.7%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H412 (69.3%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P260, P261, P264, P264+P265, P270, P272, P273, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P321, P330, P333+P317, P362+P364, P363, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 150 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard]

H412: Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P260, P264, P264+P265, P270, P273, P280, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P321, P330, P363, P405, and P501 (click each P-code to see the statement)

Protective Equipment: Wear self-contained breathing apparatus and protective clothing to prevent contact with skin and eyes.

EXTINGUISHING MEDIA. Carbon dioxide, dry chemical powder, or appropriate foam.

Emits toxic fumes under fire conditions.

Cover with dry lime or soda ash, pick up, keep in a closed container, and hold for waste disposal. Ventilate area and wash spill site after material pickup is complete.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. Observe all federal, state, and local environmental regulations.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

SRP: When working with strong solutions of acids or bases or other caustic or corrosive materials, always wear a full face mask. When working with caustic or corrosive gases or vapors, a full face mask will not protect the eyes or prevent inhaling the material. A full face respirator is required.

Do not breathe dust. Do not get in eyes, on skin, on clothing. Avoid prolonged or repeated exposure.

Wear self-contained breathing apparatus, rubber boots, and heavy rubber gloves. Wear disposable coveralls and discard them after use. In case of leak or spill, evacuate area.

For more Preventive Measures (Complete) data for MUCOCHLORIC ACID (7 total), please visit the HSDB record page.

Keep tightly closed. Store in a cool dry place.

ENGINEERING CONTROLS. Safety shower and eye bath. Use only in a chemical fume hood.

PERSONAL PROTECTIVE EQUIPMENT. Wear appropriate government approved respirator, chemical-resistant gloves, safety goggles, other protective clothing. Faceshield (8-inch minimum).

Colorless to yellowish solid; [CHEMINFO] Crystalline solid; [MSDSonline]

Monoclinic prisms from ether and ligroin

Plates from water

212 °F (100 °C): closed cup

Soluble in chlorinated and oxygenated solvents

Slightly soluble in cold water; soluble in hot water, not benzene, alcohol.

0.001 [mmHg]

When heated to decomposition it emits toxic fumes of /hydrogen chloride/.

The olfactor threshold for mucochloric acid in solution was reported to be 250 mg/L.

pKa = 4.20

Nuclear quadrupole resonance spectroscopy

Quadrupole coupling

Other Classes -> Organic Acids

Human Health. There are no reliable experimental data on the toxicokinetic behavior of mucochloric acid (MCA) in vivo available. From the results of acute toxicity studies, it is very likely that MCA itself or its metabolites are systemically available after oral exposure. In vitro, MCA reacted with N-acetylcysteine, cysteine and glutathione (GSH). The acute toxicity (LD50) of MCA was between 300 and 400 mg/kg bw in rats after oral exposure and >200 mg/kg bw (highest tested dose) in rabbits after dermal exposure. The LC50 after 4-hour inhalation exposure of rats was >5.1 mg/L (highest tested concentration). Clinical signs included atonia and ataxia after oral exposure, preening, dyspnea and salivation during inhalation, and skin irritation after dermal exposure. MCA is corrosive to the rabbit skin and eye. A guinea pig sensitization test was negative, but limited experience from occupational exposure in humans indicates a skin sensitizing potential of MCA. There is limited data on repeated dose toxicity available, indicating that irritant/corrosive effects at the site of first contact are the main effects to be expected after repeated exposure. In pregnant rats, no systemic target organ has been identified after oral exposure from day 6 to 19 p.c. (LOAEL: 30 mg/kg bw/day, based on reduced food consumption and body weight gain together with minor clinical symptoms (ptyalism) and whitish foci in the stomach interpreted as local effects due to the corrosive properties of MCA; NOAEL: 5 mg/kg bw/day). No target organ was identified in mice after dietary exposure to 7 mg/kg bw/day for 18 months (only one dose tested). ... In vitro, MCA is a direct acting mutagen and clastogen in mammalian and bacterial cells, and forms exocyclic DNA adducts. In vivo, mucochloric acid caused a slight, but statistically significant increase in the incidence of total nuclear anomalies (including micronuclei, pyknotic nuclei and karyorrhectic nuclei) in the duodenum of mice after a single oral exposure to 60.8 and 79.4 mg/kg bw. MCA induced micronuclei in one animal out of ten per dose group in the duodenum of mice after single oral doses (38.9, 60.8, and 79.4 mg/kg bw). Based on the available in vitro and in vivo data, it can be concluded that MCA has a genotoxic potential. Because of its corrosive properties, and the very limited exposure potential, animal tests with MCA for its effects on fertility were not performed. In an oral developmental study performed in accordance with OECD TG 414 in rats, the NOAEL for maternal toxicity was 5 mg/kg bw/day. The NOAEL for developmental toxicity was 60 mg/kg bw/day, which was the highest dose level applied. There were no signs of developmental toxicity or teratogenicity. MCA did not induce aberrant crypt foci or intestinal tumors when given in drinking water at dose levels of 0.45 and 0.9 mg/mL over 6 weeks to rats or at dose levels of 0.18 and 0.35 mg/mL over 4 weeks with subsequent 12-weeks recovery to mice, respectively. The available data for MCA are not sufficient to judge its carcinogenicity. Given the available data for genotoxicity there are, however, concerns with regard to this endpoint.

Dermatotoxin - Skin burns.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

LC50 (rat) = 5,100 mg/m3/4h

LD50 Mouse oral 84 mg/kg

LD50 Rat oral 0.5-1.0 g/kg

LD50 Rat ip 10-25 mg/kg

LD50 Rabbit oral 160 mg/kg bw

For more Non-Human Toxicity Values (Complete) data for MUCOCHLORIC ACID (9 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Skin: May cause allergic skin reaction.

/SIGNS AND SYMPTOMS/ ... Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. Inhalation may result in spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis, and pulmonary edema. Material is extremely destructive to tissue of the mucous membranes and upper respiratory tract, eyes, and skin.

/SIGNS AND SYMPTOMS/ Strong irritant to skin and eyes; a potent skin sensitizer.

/CASE REPORTS/ Local damage to the skin corresponding to second-degree burns developed within several hours in three people who were contaminated with mucochloric acid in a production plant. After 6 to 10 days, when the healing process had already begun, dyspeptic complaints and slight enlargement of the liver were noted in patients with more extensive local damage, while changes to biochemical parameters, particularly increases in the activities of alanine aminotransferase and lactate dehydrogenase and changes to serum proteins, mucoproteins and their fractions were reported in all patients, lasting up to 2 months in some cases.

For more Human Toxicity Excerpts (Complete) data for MUCOCHLORIC ACID (8 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ An approximate LD50 of 300 mg/kg body weight was determined in rats 7 days after the administration of a single oral dose of technical grade mucochloric acid (containing ca. 7 to 10% mother liquor). Reeling and apathy were observed after dosing. Signs of local irritation were evident on post-mortem examination of the animals that died. There were no notable effects on the organs of the animals killed after the 7-day observation period.

/LABORATORY ANIMALS: Acute Exposure/ Groups of 5 rats were treated with mucochloric acid, which was applied to a ca. 30 sq cm area of clipped abdominal skin for one hour. The acid was applied either as the pure product or neutralized with sodium bicarbonate (pH ca. 7), as a 30% aqueous tragacant suspension or aqueous solution, respectively. Treatment with the pure acid led to the deaths of 2 of the 5 rats. The rats died without exhibiting any particular signs of toxicity. The surviving 3 rats were apathetic for 2 days, but free of symptoms from the third day. After application, slight reddening and edema of the abdominal skin occurred locally, with subsequent scab formation. There were no macroscopic effects on the organs at autopsy. Jelly-like changes to the tissues in the area of the application site were observed in one rat. After application of the neutralized acid, apathy was noted after about 4 hrs lasting for 2 days, after which the rats behaved normally. One of the rats died after 5 days. Locally, reddening of the abdominal skin and edema were seen after 24 hr, with subsequent scab formation.

/LABORATORY ANIMALS: Acute Exposure/ After oral application of various specifications of mucochloric acid (MCA) to rats, the LD50 was consistently between 300 and 400 mg/kg bw. The toxicity of neutralized MCA was similar to that of the free acid indicating that the toxic effects are substance-inherent and not due to the acidic properties of MCA. Atonia and ataxia were observed as clinical symptoms of toxicity. Gross pathology after the 7-day post-exposure period showed no effects.

/LABORATORY ANIMALS: Acute Exposure/ In an acute inhalation toxicity study, 10 male and 10 female Sprague-Dawley rats were exposed to a dust aerosol of technical grade mucochloric acid for 4 hours (head-nose exposure) at an analytically determined concentration of 5.1 mg/L. During exposure, the rats made escape attempts, and exhibited muzzle wiping, closed eyes, dyspnea and salivation. At the end of the study they showed an unsteady gait and their heads were coated with the substance. During the 14-day observation period, the rats had muzzles and extremities that were reddened, and some were severely swollen, subsequently developing scabs. There were no abnormalities in any of the animals after 13 days. The LC50 was thus >5.1 mg/L.

For more Non-Human Toxicity Excerpts (Complete) data for MUCOCHLORIC ACID (35 total), please visit the HSDB record page.

LC50 Leucisus idus 100-220 mg/L/96 hr; static

/AQUATIC SPECIES/ The cytotoxicity, in Salmonella /of/ ... 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its structural analogue 3,4-dichloro-5-hydroxy-2[5H]-furanone (mucochloric acid, MCA), was studied in freshly isolated rainbow trout hepatocytes and gill epithelial cells by determining 86Rb-leakage and decrease in fluorescence intensity in calcein AM-loaded cells. The acute toxicity of the compounds to Daphnia magna was studied by determining the concentration causing immobilization of the organism. MX proved to be more toxic than MCA both in the cellular assays and in the acute toxicity test with D. magna. MX was more toxic to hepatocytes than to gill epithelial cells. The uptake of (14C)MX was also much more efficient in hepatocytes than in gill epithelial cells. The uptake of (14C)MX in hepatocytes was not inhibited by taurocholic acid in excess, indicating that MX is not taken up by the carrier complex responsible for the uptake of taurocholate in the hepatocytes. Both the acute toxicity to D. magna and cytotoxicity of MX and MCA was rather low (EC50 values > 0.1 mM) and /it was concluded/ that it is very unlikely that MX and MCA at concentrations occurring in recipients receiving chlorination effluents from pulp mills or chlorinated domestic sewage, as regards their acute toxicity, implies a risk for aquatic animals.

Mucochloric acid's production and use as a chemical intermediate may result in its release to the environment through various waste streams. Its formation in water as a result of chlorine-treatment processes may result in its release to the environment through various waste streams. Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water. If released to air, an estimated vapor pressure of 1.0X10-3 mm Hg at 25 °C indicates mucochloric acid will exist solely as a vapor in the atmosphere. Vapor-phase mucochloric acid will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 21 hours. Mucochloric acid contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, mucochloric acid is expected to have very high mobility based upon an estimated Koc of one. The pKa of mucochloric acid is 4.20, indicating that this compound will almost entirely exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize. Biodegradation data were not available. If released into water, mucochloric acid is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. The pKa indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound does not contain functional groups that hydrolyze under environmental conditions. Occupational exposure to mucochloric acid may occur through inhalation and dermal contact with this compound at workplaces where mucochloric acid is produced or used. Occupational exposure may also occur at water treatment facilities during the process of chlorine disinfection of water. The most likely pathway by which the general public is exposed to this compound is by ingestion of and dermal contact with treated drinking water and effluent. (SRC)

Mucochloric acid's production and use as a chemical intermediate(1) may result in its release to the environment through various waste streams(SRC). Its formation in water as a result of chlorine-treatment processes(2) may result in its release to the environment through various waste streams(SRC). Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water(3,4).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of one(SRC), determined from a structure estimation method(2), indicates that mucochloric acid is expected to have very high mobility in soil(SRC). The pKa of mucochloric acid is 4.20(3), indicating that this compound will almost entirely exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize. Mucochloric acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.0X10-3 mm Hg(SRC), determined from a fragment constant method(5). Biodegradataion data were not available(SRC, 2008).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of one(SRC), determined from a structure estimation method(2), indicates that mucochloric acid is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 4.20(3) indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9(4) and therefore volatilization from water surfaces is not expected to be an important fate process(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 1.37(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2008).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), mucochloric acid, which has an estimated vapor pressure of 1.0X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase mucochloric acid is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 21 hours(SRC), calculated from its rate constant of 1.8X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Mucochloric acid contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of mucochloric acid with photochemically-produced hydroxyl radicals has been estimated as 1.8X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 21 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Mucochloric acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Mucochloric acid contains chromophores that absorb at wavelengths >290 nm(2) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3 was calculated in fish for mucochloric acid(SRC), using an estimated log Kow of 1.4(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of mucochloric acid can be estimated to be 1(SRC). According to a classification scheme(2), this estimated Koc value suggests that mucochloric acid is expected to have very high mobility in soil. The pKa of mucochloric acid is 4.20(3), indicating that this compound will almost entirely exist in the anion form environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4).

A pKa of 4.20(1) indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9(2) and therefore volatilization from water surfaces is not expected to be an important fate process. Mucochloric acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.0X10-3 mm Hg(SRC), determined from a fragment constant method(3).

DRINKING WATER: Mucochloric acid concentrations in two samples of drinking water were 12 and 15 ug/L, collected from two distribution systems in Finland(1). The drinking water was derived from chlorination of surface water with an initial total organic content (TOC) of 15 mg/L, dropping to TOC of 6 mg/L following alum flocculation and sand filtration, and then disinfected with 3-5 mg/L chlorine. The resulting mucochloric acid concentration in chlorine-treated natural humic water was approximately 0.5 ug/L(1).

Mucochloric acid is a major component of chlorination-stage bleaching liquors from pulp mills, at a concentration of 1,100 ug/L(1).

Occupational exposure to mucochloric acid may occur through inhalation and dermal contact with this compound at workplaces where mucochloric acid is produced or used. Occupational exposure may also occur at water treatment facilities during the process of chlorine disinfection of water. The most likely pathway by which the general public is exposed to this compound is by ingestion of and dermal contact with treated drinking water and effluent. (SRC)

LC50 Leucisus idus 100-220 mg/L/96 hr; static

/AQUATIC SPECIES/ The cytotoxicity, in Salmonella /of/ ... 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its structural analogue 3,4-dichloro-5-hydroxy-2[5H]-furanone (mucochloric acid, MCA), was studied in freshly isolated rainbow trout hepatocytes and gill epithelial cells by determining 86Rb-leakage and decrease in fluorescence intensity in calcein AM-loaded cells. The acute toxicity of the compounds to Daphnia magna was studied by determining the concentration causing immobilization of the organism. MX proved to be more toxic than MCA both in the cellular assays and in the acute toxicity test with D. magna. MX was more toxic to hepatocytes than to gill epithelial cells. The uptake of (14C)MX was also much more efficient in hepatocytes than in gill epithelial cells. The uptake of (14C)MX in hepatocytes was not inhibited by taurocholic acid in excess, indicating that MX is not taken up by the carrier complex responsible for the uptake of taurocholate in the hepatocytes. Both the acute toxicity to D. magna and cytotoxicity of MX and MCA was rather low (EC50 values > 0.1 mM) and /it was concluded/ that it is very unlikely that MX and MCA at concentrations occurring in recipients receiving chlorination effluents from pulp mills or chlorinated domestic sewage, as regards their acute toxicity, implies a risk for aquatic animals.

Mucochloric acid's production and use as a chemical intermediate may result in its release to the environment through various waste streams. Its formation in water as a result of chlorine-treatment processes may result in its release to the environment through various waste streams. Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water. If released to air, an estimated vapor pressure of 1.0X10-3 mm Hg at 25 °C indicates mucochloric acid will exist solely as a vapor in the atmosphere. Vapor-phase mucochloric acid will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 21 hours. Mucochloric acid contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, mucochloric acid is expected to have very high mobility based upon an estimated Koc of one. The pKa of mucochloric acid is 4.20, indicating that this compound will almost entirely exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize. Biodegradation data were not available. If released into water, mucochloric acid is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. The pKa indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound does not contain functional groups that hydrolyze under environmental conditions. Occupational exposure to mucochloric acid may occur through inhalation and dermal contact with this compound at workplaces where mucochloric acid is produced or used. Occupational exposure may also occur at water treatment facilities during the process of chlorine disinfection of water. The most likely pathway by which the general public is exposed to this compound is by ingestion of and dermal contact with treated drinking water and effluent. (SRC)

Mucochloric acid's production and use as a chemical intermediate(1) may result in its release to the environment through various waste streams(SRC). Its formation in water as a result of chlorine-treatment processes(2) may result in its release to the environment through various waste streams(SRC). Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water(3,4).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of one(SRC), determined from a structure estimation method(2), indicates that mucochloric acid is expected to have very high mobility in soil(SRC). The pKa of mucochloric acid is 4.20(3), indicating that this compound will almost entirely exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize. Mucochloric acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.0X10-3 mm Hg(SRC), determined from a fragment constant method(5). Biodegradataion data were not available(SRC, 2008).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of one(SRC), determined from a structure estimation method(2), indicates that mucochloric acid is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 4.20(3) indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9(4) and therefore volatilization from water surfaces is not expected to be an important fate process(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 1.37(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2008).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), mucochloric acid, which has an estimated vapor pressure of 1.0X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase mucochloric acid is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 21 hours(SRC), calculated from its rate constant of 1.8X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Mucochloric acid contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of mucochloric acid with photochemically-produced hydroxyl radicals has been estimated as 1.8X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 21 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Mucochloric acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Mucochloric acid contains chromophores that absorb at wavelengths >290 nm(2) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3 was calculated in fish for mucochloric acid(SRC), using an estimated log Kow of 1.4(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of mucochloric acid can be estimated to be 1(SRC). According to a classification scheme(2), this estimated Koc value suggests that mucochloric acid is expected to have very high mobility in soil. The pKa of mucochloric acid is 4.20(3), indicating that this compound will almost entirely exist in the anion form environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4).

A pKa of 4.20(1) indicates mucochloric acid will exist almost entirely in the anion form at pH values of 5 to 9(2) and therefore volatilization from water surfaces is not expected to be an important fate process. Mucochloric acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.0X10-3 mm Hg(SRC), determined from a fragment constant method(3).

DRINKING WATER: Mucochloric acid concentrations in two samples of drinking water were 12 and 15 ug/L, collected from two distribution systems in Finland(1). The drinking water was derived from chlorination of surface water with an initial total organic content (TOC) of 15 mg/L, dropping to TOC of 6 mg/L following alum flocculation and sand filtration, and then disinfected with 3-5 mg/L chlorine. The resulting mucochloric acid concentration in chlorine-treated natural humic water was approximately 0.5 ug/L(1).

Mucochloric acid is a major component of chlorination-stage bleaching liquors from pulp mills, at a concentration of 1,100 ug/L(1).

Occupational exposure to mucochloric acid may occur through inhalation and dermal contact with this compound at workplaces where mucochloric acid is produced or used. Occupational exposure may also occur at water treatment facilities during the process of chlorine disinfection of water. The most likely pathway by which the general public is exposed to this compound is by ingestion of and dermal contact with treated drinking water and effluent. (SRC)

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. Observe all federal, state, and local environmental regulations.