Technical Review of Hydrogen Sulfide:

Chemistry, Environmental Fate and Ecological Toxicity

CAS Registry Number 7783-06-4

Office of Environmental Information

Office of Information Access and Analysis 

Environmental Analysis Division

Analytical Support Branch

October 5, 2009
i

Purpose of this Hazard Assessment for Hydrogen Sulfide

This technical report provides an assessment and review of the potential environmental

hazards of hydrogen sulfide. Information provided includes a review of available literature 

concerning ecological toxicity along with a brief review of the chemistry and environmental fate 

of the chemical. The document assesses the scientific soundness of the readily available 

data/studies including an assessment of the dose or concentration levels at which adverse 

effect(s) were observed. 
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TABLE OF CONTENTS

1. CHEMISTRY AND ENVIRONMENTAL FATE...............................................................1

1.1. SUMMARY...................................................................................................................................................................1

1.2. SYNONYMS/IDENTIFIERS.....................................................................................................................................3

1.3. PHYSICAL AND CHEMICAL PROPERTIES .....................................................................................................3

1.4. PRODUCTION METHODS......................................................................................................................................4

1.5. USE PROPERTIES.....................................................................................................................................................5

1.6. ENVIRONMENTAL FATE.......................................................................................................................................6

1.7. REFERENCES...........................................................................................................................................................12

2. ECOLOGICAL HAZARD ASSESSMENT.......................................................................15

2.1. SUMMARY.................................................................................................................................................................15

2.2. ECOLOGICAL TOXICITY....................................................................................................................................16

2.3. REFERENCES...........................................................................................................................................................24
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1. CHEMISTRY AND ENVIRONMENTAL FATE

H

S

H

1.1. SUMMARY 

Hydrogen sulfide (CAS Registry No. 7783-06-4) is a colorless, flammable gas at room 

temperature that has an odor of rotten eggs (O'Neil et al., 2006; Lewis, 2001). The molecular 

formula is H2S and the molecular weight is 34.08. Hydrogen sulfide is described as soluble over 

a wide range of temperatures and pressure (Carroll and Mather 1989)). It is soluble in certain 

polar organic solvents (e.g., methanol, acetone, glycols, and glycol ethers), less soluble in nonpolar solvents (e.g., hexane, benzene), and very soluble in alkanolamines (Weil et al., 2006).

Hydrogen sulfide is a component of the natural sulfur cycle. It is produced by natural 

bacterial processes in the environment and is found naturally in crude oil, natural gas, sulfur 

springs, and volcanic gas (Beauchamp et al., 1984; Boon, 1992; Weil et al., 2006). Most of the 

hydrogen sulfide used commercially is recovered from petroleum, natural gas, and manufactured 

gas; however, hydrogen sulfide is also manufactured via reactions involving other industrial 

chemicals such as sulfur and hydrogen gas (Pouliquen et al. 2005). Hydrogen sulfide is also 

produced as an incidental degradation product by the biological wastewater treatment industry, 

the agricultural food industry, slaughterhouses and the paper industry (Ulmann’s, 1989). 

Some important uses of hydrogen sulfide include the manufacture of elemental sulfur, 

metal sulfides, and thioorganic compounds, and the purification of metal ore. According to 

industrial reports provided to the U.S. Environmental Protection Agency (U.S. EPA) under the 

Inventory Update Rule (U.S. EPA, 2007a), the production volume of hydrogen sulfide in the 

United States declined from greater than 1 billion pounds per year in 1986 to between 100 and 

500 million pounds in 1998 and then returned to greater than 1 billion pounds in 2002. More 

recent production volume data are not available. 
2

An estimated 100-324 million tons of hydrogen sulfide are naturally released to the 

global atmosphere each year (Pouliquen et al., 2005). Releases from ocean waters are believed 

to account for half of this volume, with the remainder originating from volcanoes, flooded 

ground, and hydrogeological sources such as thermal springs (Pouliquen et al., 2005). Although 

hydrogen sulfide is on the current Toxics Release Inventory (TRI) toxic chemical list, releases 

for this chemical are not currently reportable (U.S. EPA, 2007b). Anthropogenic releases of 

hydrogen sulfide have been estimated to account for less than 5% of total atmospheric hydrogen 

sulfide emissions (Beauchamp et al., 1984).

Since hydrogen sulfide is a gas at environmental temperatures, it is expected to volatilize 

from water and soil surfaces. Hydrogen sulfide has also been shown to sorb to soil surfaces 

resulting in attenuation in its transfer rate to the atmosphere (Smith et al., 1973). The 

volatilization rate of hydrogen sulfide in the environment is also influenced by pH. Under basic 

conditions, hydrogen sulfide dissociates to form bisulfide, a substance that does not volatilize.

Hydrogen sulfide released to the atmosphere is expected to undergo indirect 

photooxidation with hydroxyl radicals. The predicted lifetime based on this reaction is 0.23-2.3 

days (Cox, 1975). This substance also undergoes oxidation by reaction with atmospheric oxygen 

(O2) and ozone (Hill, 1973). Measured rates for these processes are not available; however, halflives are expected to be less than 1 day (Hill, 1973). Hydrogen sulfide is expected to undergo 

oxidation in soil and water through both abiotic and biological processes (Millero et al., 1987; 

Jorgensen, 1982; WHO, 1981; Hill, 1973). 

The chemistry and environmental fate of hydrogen sulfide are discussed in this chapter. 

Synonym and physical-chemical property information was obtained during a search of the online source ChemIDplus, handbook references, the Syracuse Research Corporation (SRC) 

PHYSPROP database, and the SRC Environmental Fate Data Base. Manufacturing and use 

information was obtained from Ullmann's encyclopedia articles on hydrogen sulfide. 
3

Environmental fate data were obtained through a search of the literature compiled in SRC's 

Environmental Fate Data Base, the Hazardous Substances Data Bank (HSDB) record for 

hydrogen sulfide, the Agency for Toxic Substances and Disease Registry (ATSDR) toxicological 

profile for hydrogen sulfide, and estimations performed using the EPI Suite v4.0 software.

1.2. SYNONYMS/IDENTIFIERS 

(CAS 2007; ChemIDplus, 2008):

Dihydrogen monosulfide

Dihydrogen sulfide

Hydrosulfuric acid

Stink damp

Sulfur dihydride

Sulfur hydride

Sulfureted hydrogen

1.3. PHYSICAL AND CHEMICAL PROPERTIES

Table 1-1 provides selected physical and chemical properties for hydrogen sulfide.
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Table 1-1. Physical and Chemical Properties of Hydrogen Sulfide (CAS Reg. No. 7783-06-4)

Property Valuea Conditions Reference

Molecular formula H2S O'Neil et al., 2006

Molecular weight 34.08 O'Neil et al., 2006

Melting point (°C) -85.49 O'Neil et al., 2006

Boiling point (°C) -60.33 O'Neil et al., 2006

Water solubility (mg/L)

b,c 3787

2821

2329

20 °C

30 °C

40 °C

Carroll and Mather 1989

Log Kow NA

Henry’s Law constant (atmm3

/mol)

8.4×10-3

1.08×10-2

1.3×10-2

20 °C; pH 7.1

30 °C; pH 7.1

40 °C; pH 7.1

Al-Haddad et al., 1989; Carroll and 

Mather 1989

Air-water partition coefficient 

(Kaw)

0.35

0.43

0.51

20 °C

30 °C

40 °C

Calculated from the Henry’s Law 

constant using data from Carroll and 

Mather 1989

Hydroxyl radical reaction rate 

constant (cm3/molec-sec)

4.8×10-12 Cox, 1975

pKa 7.04 O'Neil et al., 2006

Density (g/L) 1.393 Lide, 2005

Density in air (air = 1) 1.19 O'Neil et al., 2006

Autoignition temperature (°C) 290 Pouliquen et al., 2005

Explosive limits (by volume) Lower limit: 4.3%

Upper limit: 46%

O'Neil et al., 2006

Odor threshold (ppm) Water: 0.000029

Air: 0.0005-0.3

ATSDR, 2006

Air conversion factors 1 ppm = 1.40 mg/m3 ATSDR, 2006

a

Values are experimental unless otherwise indicated.

b

 The solubility of hydrogen sulfide in water is calculated from the strict Henry’s Law constant over a wide temperature and 

pressure range (Carroll and Mather 1989): mH2S H = yH2S P, where yH2S is the mol fraction of hydrogen sulfide in the vapor phase, 

P is the total pressure, and mH2S is the mol fraction of hydrogen sulfide in solution. Multiplying yH2S by P yields the partial 

pressure of hydrogen sulfide above the solution. 

c

 These solubilities were originally reported as mol percent in Carroll and Mather (1989) and were converted to mg/L for this 

table.

1.4. PRODUCTION METHODS

 Most of the hydrogen sulfide used commercially is obtained through recovery from 

petroleum, natural gas, or manufactured gas (Beauchamp et al., 1984). In a process called 

hydrodesulfurization, sulfur-rich gas-oil and coke distillate fractions are passed through a fixedbed catalyst in the presence of hydrogen to convert the sulfur compounds into hydrogen sulfide 

(Beauchamp et al., 1984). Hydrogen sulfide is also produced through hydrogen reduction or acid 

decomposition of sulfides such as FeS2 or CuS (Pouliquen et al., 2005). An older commercial 
5

production method involves the direct reaction of sulfur with hydrogen gas or with a 

hydrocarbon (Weil et al., 2006; Pouliquen et al., 2005; Beauchamp et al., 1984). For example, 

methane is reacted with sulfur to form a mixture of hydrogen sulfide and carbon disulfide 

(Pouliquen et al., 2005). The carbon disulfide can then be hydrolyzed to give additional 

hydrogen sulfide (Pouliquen et al., 2005).

Hydrogen sulfide is formed through bacterial reduction of naturally occurring or 

anthropogenic sulfate and bacterial decomposition of sulfur-containing proteins, and it is a 

principal component of the natural sulfur cycle (Weil et al., 2006; Boon, 1992; WHO, 1981). It 

is generated as a degradation product by the biological wastewater treatment industry, 

agricultural food industry, slaughterhouses and the paper industry (Ulmann’s, 1989). Hydrogen 

sulfide is present in crude oil, natural gas, sulfur springs, and volcanic gas (Beauchamp et al., 

1984). It is released to the environment via water discharge during oil and gas extraction 

activities (EPA, 1993). The concentration of undissociated hydrogen sulfide in an 

environmental water sample can be calculated from the dissolved sulfide concentration measured 

in the sample and the pH, salinity, and temperature of the solution (APHA 1998).

1.5. USE PROPERTIES 

 Hydrogen sulfide is used in the production of elemental sulfur and sulfuric acid, in the 

production of inorganic sulfides, thiophenes, organic mercaptans, thioaldehydes, and 

thioketones, in the metallurgical industry for the purification of ore through selective flotation, in 

the manufacture of heavy water for the nuclear industry, and as a reagent in analytical chemistry 

(HSDB, 2007; O'Neil et al., 2006; Weil et al., 2006; Pouliquen et al., 2005; Lewis, 2001; 

Beauchamp et al., 1984).
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1.6. ENVIRONMENTAL FATE

1.6.1. Environmental Transport. Since hydrogen sulfide is a gas, it is expected to partition to 

the atmosphere; however, atmospheric hydrogen sulfide may dissolve in water that it contacts 

and sorb onto soil and plant surfaces (ATSDR, 2006). Along with sorption to soils, the natural 

diffusion of hydrogen sulfide from areas of greater concentration to areas of lower concentration 

will also influence the amount of hydrogen sulfide found in soil compartments.

Measured Henry's Law constants of 8.4×10-3, 1.08×10-2, and 1.3×10-2 atm-m3/mol at 20, 

30, and 40 °C, respectively (pH 7.1), and the corresponding air-water partition coefficients 

shown in Table 1-1 indicate that increasing temperature increases the rate of hydrogen sulfide 

volatilization from water (ATSDR, 2006; Al-Haddad et al., 1989; Carroll and Mather 1989). 

Using a Henry's Law constant of 8.4×10-3 atm-m3/mol at 20 °C and the EPI Suite estimation 

software (U.S. EPA, 2009), the volatilization half-lives of hydrogen sulfide are calculated to be 

38 minutes for a model river1 and 2.3 days for a model lake2. Please note that hydrogen sulfide 

is not a typical organic molecule and therefore caution must be used when interpreting the results 

of the EPI Suite program for this substance. These volatilization half-lives may overestimate the 

rate at which volatilization may be occurring due to the fact that the EPI Suite software does not 

take into consideration the dissociation of hydrogen sulfide which increases with increasing pH 

above a pH of 5 (Balls and Liss, 1983). 

Hydrogen sulfide is a weak acid with a pKa value of 7.04 (O'Neil et al., 2006). The 

hydrogen sulfide molecule and the bisulfide anion (HS–) will both be present in waters at 

environmental pH (5-9) (SPARC, 2008; Balls and Liss, 1983). The ratio of bisulfide to 

hydrogen sulfide increases with increasing pH, with approximately 100% hydrogen sulfide at pH 

5, approximately equal percentages of both species at pH 7, and approximately 100% bisulfide at 

pH 9 (SPARC, 2008; Balls and Liss, 1983). This pH-dependent relationship is illustrated 

 1

 Parameters for the model river are 1 m deep, flowing 1 m/sec, wind velocity of 5 m/sec.

2

 Parameters for the model lake are 1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec.
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graphically in Figure 1-1. Bisulfide that forms from the dissociation of hydrogen sulfide in 

environmental waters will not volatilize since it is an ionic species. 

Figure 1-1. Speciation of Hydrogen Sulfide as a Function of pH.

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 101112 1314 15

pH

H2S

HSThe earth’s surface may act as a natural sink for hydrogen sulfide because soils have been 

shown to sorb this and other gases (Smith et al. 1973). The adsorption capacity of hydrogen 

sulfide in 6 different soils ranged from 15.4 to 65.2 mg hydrogen sulfide per gram of soil in airdry samples and from 11.0 to 62.5 mg hydrogen sulfide per gram of soil in moist samples (50% 

water holding capacity) (Smith et al., 1973). The tests were conducted at room temperature with 

1 gram samples of soils in sealed 65 mL containers into which 5 mL of gas were injected. The 

gas injection was repeated, if necessary until chromatographic analysis showed that little, if any, 

further sorption took place. All the soils had similar adsorption isotherms for hydrogen sulfide 

with the exception of a sandy Thurman series soil obtained from Iowa (>90% sand). This soil 
8

had the lowest capacity to adsorb hydrogen sulfide (and all the other gases tested), presumably 

due to the low surface area per unit weight of the soil. 

1.6.2. Abiotic Degradation. Atmospheric oxidation of hydrogen sulfide by oxygen, ozone, or 

hydroxyl radicals produces sulfur dioxide (Hill, 1973). Measured rates for the atmospheric 

oxidation via reaction with O2 and O3 are not available; however, half-lives are expected to be 

less than 1 day (Hill, 1973). Hydrogen sulfide reaction rates with photochemically produced 

hydroxyl radicals was measured by Cox (1975) at a rate constant of 4.8×10-12 cm3/molecule-sec. 

The author used this rate constant to calculate photooxidation lifetimes of 0.23 days using a 

summer daytime hydroxyl radical concentration of 107 molecules/cm3 and 2.3 days using a yearround average hydroxyl radical concentration 106

 molecules/cm3. Bottenheim and Strausz 

(1980) concluded that reaction of atmospheric hydrogen sulfide with hydroxyl radicals is 

negligible during the winter based on an estimated lifetime of 41.9 days for that time of year. 

Based on the measured rate constant of 4.8×10-12 cm3/molecule-sec reported by Cox (1975), an 

atmospheric photooxidation half-life of 26.7 hours can be calculated assuming an atmospheric 

hydroxyl radical concentration of 1.5×106 molecules/cm3 and a 12-hour day. Hydrogen sulfide 

is not expected to undergo direct photolysis in the atmosphere (Cox, 1975).

Hydrogen sulfide in environmental waters is oxidized by oxygen (O2) to form sulfur 

dioxide and eventually sulfate. Reported oxidation half-life values measured in air-saturated 

solutions at 25 °C and pH 8 are 50 hours in fresh water and 26 hours in seawater (Millero et al., 

1987). Other studies of oxidation rates of hydrogen sulfide in fresh and sea water have reported 

a variable range of half-life values which may is in part be due to differences in experimental 

conditions including pH, temperature and ionic strength of the test solution and analytical 

methodology employed (Millero et al., 1987) 
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1.6.3. Biotic Degradation. Hydrogen sulfide is a major component of the natural sulfur cycle 

(WHO, 1981; Hill, 1973). Hydrogen sulfide is released into the environment by bacterial 

reduction of sulfate reduction processes and protein decomposition, especially under low-oxygen 

(anaerobic) conditions and in locations where readily decomposable organic matter is present 

(Boon, 1992; Hill, 1973). Higher levels of hydrogen sulfide are found in waters rich in organic 

matter such as flooded ground (e.g., swamps, bogs) (Pouliquen 2005). The reverse process, 

microbial oxidation of hydrogen sulfide to elemental sulfur or sulfate, is also observed 

(Jorgensen, 1982; Hill, 1973). Greater than 85% 35S-labeled hydrogen sulfide added to oxic 

water collected from the Black Sea chemocline was degraded after 1 day of incubation 

(Jorgensen, 1982). Although transformation rates were similar in both the untreated and 

chloroform-killed samples, differences in sulfate/thiosulfite accumulation indicated that bacterial 

processes were responsible for some of the transformation in the untreated water. 

Approximately 90% of hydrogen sulfide added to chemocline water samples from Solar Lake, 

Sinai Peninsula was transformed by both abiotic and biological oxidation after 12 minutes 

incubation (Jorgensen, 1982).

1.6.4. Environmental Distribution Assessment. A model (U.S. EPA, 2009) estimate was 

conducted of how, on a percentage basis, hydrogen sulfide would distribute in the environment if 

released at rates of 900, 100, and 0 kg per hour to the air, water, and soil environmental 

compartments, respectively. Measured physical-chemical properties (melting point, boiling 

point, vapor pressure, water solubility, and Henry's law constant) were used as model input 

parameters. Model half-life input values were assigned based on the photooxidation half-life for 

air (26.7 hours) and a reported oxidation half-time of 50 hours in fresh water for the water, soil, 

and sediment compartments. The advective flow rate was set to zero by selecting very large 

advection times (1×1020 hours) for the air, water, and sediment environmental compartments. A 
10

measured Henry's law constant of 8.4×10-3 atm-m3/mol at 20°C and pH 7.1 from Carroll and 

Mather (1989) and a measured vapor pressure value of 1.5×104 mm Hg at 25°C from Daubert 

and Danner (2000) were used as input parameters to satisfy the requirements of the fugacity 

model. The results of this model calculation suggest that for this release scenario (90% to air and 

10% to water), most hydrogen sulfide will remain in the air with the rest partitioning to the water 

environmental compartment (85% air; 15% water; 0 % soil and sediment). The model 

partitioning results, half-life inputs, and emissions inputs for each environmental compartment 

under this release scenario are shown in Table 1-2.

Table 1-2, Environmental Distribution of Hydrogen Sulfide Based on 90% Release to air and 

10% Release to Water

Compartment Mass amount 

(percent)

Half-life Values 

(hours) 

Emissions

(kg/hr)

Air 85.1% 26.7 900

Water 14.9% 50 100

Soil 0.00241% 50 0

Sediment 0.00482% 50 0

Source: EPI Suite, (U.S. EPA, 2009)

The distribution estimate was also performed for equal emissions (1000 kg per hour) to 

the air, water, and soil environmental compartments. All other input parameters remained the 

same. The results of this calculation suggest that for an equal release scenario, most hydrogen 

sulfide will partition to air and water with a small amount partitioning to soil (49% air; 41% 

water; 10% soil; 0% sediment). The model partitioning results, half-life inputs, and emissions 

inputs for each environmental compartment under an equal release scenario are shown in Table 

1-3.
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Table 1-3, Environmental Distribution of Hydrogen Sulfide Based on Equal Releases to Air, 

Water, and Soil

Compartment Mass amount 

(percent)

Half-life Values 

(hours) 

Emissions

(kg/hr)

Air 49% 26.7 1000

Water 40.7% 50 1000

Soil 10.3% 50 1000

Sediment 0.0132% 50 1000

Source: EPI Suite, (U.S. EPA, 2009)

The volatilization half-lives calculated within the fugacity model may overestimate the 

rate at which volatilization may be occurring due to the fact that the EPI Suite software does not 

take into consideration the dissociation activity of hydrogen sulfide which increases with 

increasing pH above a pH of 5 (Balls and Liss, 1983). 

1.6.5. Toxic Transformation Products. Atmospheric oxidation of hydrogen sulfide by oxygen, 

ozone, or hydroxyl radicals produces sulfur dioxide (Hill, 1973). Sulfur dioxide is ultimately 

oxidized to form sulfate, which can be washed out of the atmosphere as sulfuric acid when 

dissolved in rain droplets (Hill, 1973). The relative toxicities of hydrogen sulfide, sulfur dioxide, 

and sulfuric acid are reflected in the ACGIH (ACGIH, 2007) recommended limits for these 

chemicals in workplace air (Table 1-4).
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Table 1-4. ACGIH Recommended Limits for Hydrogen Sulfide, Sulfur Dioxide, and Sulfuric 

Acid in Workplace Air

ACGIH

TLV-TWAa

ACGIH

TLV-STELb

Hydrogen sulfide 10 ppm (14.1 mg/m3) 15 ppm (21.3 mg/m3)

Sulfur dioxide 2 ppm (5.3 mg/m3) 5 ppm (13.3 mg/m3)

Sulfuric acid 0.2 mg/m3 Not available

a

Threshold Limit Value–Time-Weighted Average (TLV-TWA) – The time-weighted average concentration for a conventional 

8-hour workday and a 40-hour workweek, to which it is believed that nearly all workers may be repeatedly exposed, day after 

day, for a working lifetime without adverse effect. b

Threshold Limit Value–Short-Term Exposure Limit (TLV-STEL) – A 15-minute time-weighted average exposure that should 

not be exceeded at any time during a workday, even if the 8-hour time-weighted average is within the TLV-TWA.

Source: ACGIH, 2007.

1.7. REFERENCES

ACGIH (American Conference of Governmental Industrial Hygienists). 2007. Hydrogen 

sulfide, sulfur dioxide, and sulfuric acid. In: Threshold limit values for chemical substances and 

physical agents and biological exposure indices. Cincinnati, OH: ACGIH. p. 34, 53.

Al-Haddad A.A., M.S.E. Abdo, and S.A. Abdul-Wahab. 1989. Evaluation of Henry's constant 

for H2S in water and sewage effluents. J. Environ. Sci. Health. Part A. 24(3):207-227.

APHA (American Public Health Association). 1998. Method 4500 S2- Sulfide. Standard 

methods for the examination of waste and wastewater. 20th ed. Washington, DC: 4-162 to 4-

173.

ATSDR (Agency for Toxic Substances and Disease Registry). 2006. Toxicological profile for 

hydrogen sulfide-update. Agency for Toxic Substances and Disease Registry, Centers for 

Disease Control and Prevention. PB2007100675. Available at: 

http://www.atsdr.cdc.gov/toxprofiles/tp114.html.

Balls, P.W. and P.S. Liss. 1983. Exchange of H2S between water and air. Atmos. Environ. 

17:735-742.

Beauchamp, R.O. Jr., J.S. Bus, J.A. Popp, C.J. Boreiko, and D.A. Andjelkovich. 1984. A 

critical review of the literature on hydrogen sulfide toxicity. CRC Crit. Rev. Toxicol. 13(1):25-

97.

Boon, A.G. 1992. Sepacity in sewers: Causes, consequences and containment. J. Inst. Water 

Environ. Manage. 6:79-90.

Bottenheim J.W. and O.P. Strausz. 1980. Gas-phase chemistry of clean air at 55 degrees N 

latitude. Environ. Sci. Technol. 14:709-718.

Carroll J.J. and A.E. Mather. 1989. The solubility of hydrogen sulphide in water from 0 to 90°C 

and pressures to 1 MPa. Geochim. Cosmochim. Acta. 53:1163-1170.
13

CAS (Chemical Abstracts Service). 2007. On-line search. American Chemical Society. 

Available at: http://www.cas.org.

ChemIDplus. 2008. Hydrogen sulfide (RN: 7783-06-4). ChemIDplus. U.S. National Library of 

Medicine. Available at: http://chem.sis.nlm.nih.gov/chemidplus/chemidheavy.jsp. 

Cox, R.A. 1975. Atmospheric photo-oxidation reactions: The gas phase reaction of OH 

radicals with some sulphur compounds. Harwell: Environmental and Medical Sciences 

Division, United Kingdom Atomic Authority. AERE-R8132.

Daubert, T.E. and R.P Danner, Eds. 2000. Property constants: Hydrogen sulfide. In: Physical 

and thermodynamic properties of pure chemicals: Data compilation. Washington, DC: Taylor 

& Francis.

Hill, F.B. 1973. Atmospheric sulfur and its links to the biota. Brookhaven Symp. Biol. 30:159-

181.

HSDB (Hazardous Substances Data Bank). 2007. Hydrogen sulfide. Hazardous Substances 

Data Bank. National Library of Medicine. Available at: http://toxnet.nlm.nih.gov. 

Jorgensen, B.B. 1982. Ecology of the bacteria of the sulphur cycle with special reference to 

anoxic-oxic interface environments. Philos. Trans. R. Soc. Lond., B, Biol. Sci. 298:543-561.

Lewis, R.J., Ed. 2001. Hydrogen sulfide. In: Hawley's condensed chemical dictionary. New 

York: John Wiley & Sons, Inc. p. 588-589.

Lide, D.R., Ed. 2005. Hydrogen sulfide. In: CRC handbook of chemistry and physics. Boca 

Raton: Taylor & Francis Group. p. 4-65.

Millero, F.J., S. Hubinger, M. Fernandez, and S. Garnett. 1987. Oxidation of H2S in sea water 

as a function of temperature, pH and ionic strength. Environ. Sci. Technol. 21:439-443.

O'Neil, M.J., P.E. Heckelman, C.B. Koch, and K.J. Roman, Eds. 2006. Hydrogen sulfide. In: 

The Merck index. Whitehouse Station, NJ: Merck & Co. Inc. p. 831-832.

Pouliquen, F., C. Blanc, E. Arretz, et al. 2005. Hydrogen sulfide. In: Ullmann's encyclopedia 

of industrial chemistry. Wiley-VCH Verlag GmbH & Co. Available at: 

http://www.mrw.interscience.wiley.com.

Smith, K.A., J.M. Bremner, and M.A. Tabatalag. 1973. Sorption of gaseous atmospheric 

pollutants by soils. Soil Sci. 116:313-319.

SPARC. 2008. SPARC online calculator – Version 4.1. University of Georgia and U.S. 

Environmental Protection Agency. Available at: http://sparc.chem.uga.edu/sparc/.

Ulmann’s, 1989. Ullmann’s Encyclopedia of Industrial Chemistry, Fifth Revised Edition, VCH 

Publishers, Weinheim, Germany. Vol A13, p476.
14

U.S. EPA (U.S. Environmental Protection Agency). 1993. Report to Congress on hydrogen 

sulfide air emissions associated with the extraction of oil and natural gas. Research Triangle 

Park, NC: U.S. Environmental Protection Agency, Office of Air Quality Planning and 

Standards. EPA453R93045. PB94131224.

U.S. EPA. 2007a. Inventory update reporting. U.S. Environmental Protection Agency. 

Available at: http://www.epa.gov/oppt/iur/.

U.S. EPA. 2007b. TRI Explorer: Providing access to EPA’s toxics release inventory data. 

Washington, DC: U.S. Environmental Protection Agency, Toxics Release Inventory. Available 

at: http://www.epa.gov/triexplorer/.

U.S. EPA. 2009. Estimation Programs Interface SuiteTM v4.0. U.S. Environmental Protection 

Agency. Available at: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm. 

Weil, E.D., S.R. Sandler, and M. Gernon. 2006. Sulfur compounds. In: Kirk-Othmer 

encyclopedia of chemical technology. John Wiley & Sons, Inc. Available at: 

http://www.mrw.interscience.wiley.com.

WHO (World Health Organization). 1981. Environmental health criteria for hydrogen sulfide. 

World Health Organization. International Programme on Chemical Safety. Available at: 

http://www.inchem.org/documents/ehc/ehc/ehc019.htm.
15

2. ECOLOGICAL HAZARD ASSESSMENT

 2.1. SUMMARY 

Hydrogen sulfide is a biologically active compound that is of toxicological concern 

primarily when in a neutral state (H2S) as opposed to an ionic state (HS-, S-2) (U.S. EPA, 1986). 

Hydrogen sulfide is expected to present a significant concern for adverse effects on the 

environment. This conclusion is based on both acute, chronic and early-life stage experimental 

toxicity values for aquatic organisms.

As presented in Table 2-1, acute toxicity values (96-hour LC50 values) for freshwater fish 

ranged from 0.016 to 0.0448 mg/L, indicating high aquatic toxicity; for estuarine/marine fish, a 

single 96-hour LC50 value of 1.43 mg/L was available. Chronic toxicity values for freshwater 

fish ranged from a 6-week Lowest Observed Effect Concentration (LOEC) (growth rate) of 

0.0005 mg/L in a tropical fish Mystus nemurus to a 430-day LOEC (final weight) of 0.009 mg/L 

for goldfish. These observed adverse effects noted for the chronic exposure of freshwater fish at 

the above low concentrations also indicate high aquatic toxicity for hydrogen sulfide. 

Additionally, in early-life stage toxicity testing with eggs, fry, and juveniles of various 

freshwater fish species, endpoint values ranged from a 96-hour LC50 of <0.002 mg/L (yellow 

perch sac fry) to a 96-hour LC50 value of 0.0536 mg/L (fathead minnow). For estuarine/marine 

fish, a 24-hour LC100 of 2.9 mg/L was reported for Black Sea turbot eggs.

Hydrogen sulfide also demonstrated high toxicity to aquatic invertebrates. Ninety-sixhour LC50 values for freshwater invertebrates ranged from 0.02 to 1.07 mg/L, and 48- to 96-hour 

EC/LC50 values for estuarine/marine invertebrates ranged from 0.01 to 0.332 mg/L. Chronic 

values for freshwater invertebrates ranged from a 65-day LOEC (reproduction) of 0.0031 mg/L 

to a 10-day LC50 value of 0.042 mg/L, both for the amphipod Gammarus pseudolimnaeus. For 

estuarine/marine invertebrates, the only chronic endpoint value available was a 49-day LOEC 

(based on decreased wet weight) of 1.12 mg/L for the sea urchin. Additionally, in early-life 
16

stage toxicity testing, a 96-hour LC50 value of 0.034 mg/L was available for juvenile crayfish 

(freshwater species); for estuarine/marine invertebrates, 48-hour LC50 values of 0.0087 mg/L and 

0.0185 mg/L were available for white shrimp larvae and juveniles, respectively. 

No experimental toxicity data were available for algae. Hydrogen sulfide is not expected 

to bioaccumulate significantly in aquatic organisms. The bioconcentration factor (BCF) is 

approximately 3 (U.S. EPA, 2009). 

2.2. ECOLOGICAL TOXICITY

Databases searched to identify studies on ecological toxicity were ECOTOX (2007) 

(which contains three databases: AQUIRE, PHYTOTOX, and TERRETOX), the Office of 

Pesticide Programs (OPP) Environmental Fate and Effects Division (EFED) Pesticide 

Ecotoxicity Database, and the Hazardous Substances Databank (HSDB, 2007). In addition, the 

TOXLINE database (TOXLINE, 2007) was searched to identify additional aquatic toxicity 

studies and population effects studies. No laboratory data on algal toxicity or toxicity to 

terrestrial animals and plants were found.

Table 2-1 presents the experimental values for acute and chronic toxicity of hydrogen 

sulfide to aquatic organisms and toxicity to terrestrial organisms. The lowest experimental 

endpoint values available from a given study were selected for inclusion in the table. If multiple 

values were available for different life stages within a given study (e.g., multiple LC50 values for 

fish eggs, and multiple LC50 values for juveniles within the same study), then the lowest values 

available for each life stage were selected for inclusion in Table 2-1 (e.g., lowest LC50 for fish 

eggs and lowest LC50 for juveniles). Endpoint values for durations longer than 96 hours but 

shorter than 28 days (for fish) and 21 days (for aquatic invertebrates) were included in the 

chronic toxicity sections of Table 2-1, although it is acknowledged that toxicity tests with 

durations less than 28 days and aquatic invertebrate toxicity tests with durations less than 21 
17

days are typically not considered chronic tests. When interpreting results of hydrogen sulfide 

aquatic toxicity testing, care should be taken to consider the potential effects of pH, temperature, 

and dissolved oxygen concentration in combination with hydrogen sulfide exposure. As 

indicated in Section 1.6.1, the proportion of hydrogen sulfide is dependent on the pH of the 

water, with more basic pH levels leading to decreased amounts of hydrogen sulfide and 

increased amounts of the bisulfide anion (HS-). Additionally, as stated in Section 1.6.1, 

increasing temperature generally increases the rate of hydrogen sulfide volatilization from water. 

Regarding dissolved oxygen, some data indicate that hydrogen sulfide toxicity can increase when 

combined with hypoxic test conditions (Kang & Matsuda, 1994).

Table 2-1. Ecological Toxicity Values for Hydrogen Sulfidea

Species Duration and Test 

Endpoint

pH During 

Teste

Experimental 

Typeb,c

Value 

(mg/L)d Reference

Acute aquatic toxicity

Algae - No data

Freshwater invertebrate

Freshwater amphipod (Gammarus 

pseudolimnaeus) 96-hour LC50 7.9 F, M 0.021

Oseid and Smith, 1974a (Table 

2); Smith and Oseid, 1975 (Table 

2); U.S. EPA, 1976 (Table 115)

Freshwater amphipod (G. 

pseudolimnaeus) 96-hour LC50 7.5 F, M 0.059 Oseid and Smith, 1974b (Table 14); U.S. EPA, 1976 (Table 122)

Crayfish (Cambarus diogenes) –

sub-adult 96-hour LC50 7.70 (mean) F, M 0.070 U.S. EPA, 1976 (Table 103)

Ephemeroptera (Baetis vagans) 96-hour LC50 7.6 F, M 0.020 Oseid and Smith, 1974b (Table 

14); U.S. EPA, 1976 (Table 122)

Ephemeroptera (Ephemera 

simulans) 96-hour LC50 7.4 F, M 0.316 Oseid and Smith, 1974b (Table 14); U.S. EPA, 1976 (Table 122)

Ephemeroptera (Hexagenia 

limbata) 96-hour LC50 7.7 F, M 0.030 U.S. EPA, 1976 (Table 118)

Ephemeroptera (H. limbata) 96-hour LC50 7.7 F, M 0.111 Oseid and Smith, 1974b (Table 

14); U.S. EPA, 1976 (Table 122)

Amphipod (Crangonyx 

richmondensis laurentianus) 96-hour LC50 7.4 F, M 0.840 Oseid and Smith, 1974b (Table 14); U.S. EPA, 1976 (Table 122)

Isopod (Assellus militaris) 96-hour LC50 7.5 F, M 1.070 Oseid and Smith, 1974b (Table 

14); U.S. EPA, 1976 (Table 122)

Freshwater fish

Fathead minnow (P. promelas) 96-hour LC50

8.693 

(mean)g F, M 0.0149 Broderius et al., 1977 (Table 3)
18

Species Duration and Test 

Endpoint

pH During 

Teste

Experimental 

Typeb,c

Value 

(mg/L)d Reference

Fathead minnow (P. promelas) 96-hour LC50 7.9 F, M 0.0160 U.S. EPA, 1976 (Table 6)

Fathead minnow (P. promelas) 96-hour LC50

7.698 

(mean) F, M 0.0382 Broderius et al., 1977 (Table 3)

Rainbow trout (S. gairdneri) – fry 96-hour TL50j 7.6-8.0 F, M 0.0200 Smith and Oseid, 1972 (page 

718)

Bluegill (L. macrochirus) 96-hour LC50 7.8-8.0 F, M 0.0448 Smith et al., 1976a (Table 2)

White sucker (C. commersoni) 96-hour LC50 7.8 F, M 0.0185 U.S. EPA, 1976 (Table 101)

Goldfish (C. auratus) 96-hour LC50 7.69 (mean) F, M 0.0440 U.S. EPA, 1976 (Table 40)

Estuarine/marine invertebrate

Saltwater shrimp (Penaeus 

indicus) 96-hour LC50 6.0-6.3 F, M 0.0630 Gopakumar and Kuttyamma, 1996 (Table 1) 

Saltwater shrimp (Metapenaeus 

dobsoni) 96-hour LC50 6.0-6.3 F, M 0.0770 Gopakumar and Kuttyamma, 1996 (Table 1)

Saltwater mussel (Mytilus edulis) 48-hour EC50 7.9-8.1 F, M 0.010p Knezovich et al., 1996

Sea urchin (Strongylocentrotus 

purpuratus) 48-hour EC50 7.9-8.1 F, M 0.019p Knezovich et al., 1996

Adult amphipod (Eohaustorius 

estuarius) 48-hour LC50 7.9-8.1 F, M 0.160p Knezovich et al., 1996

Adult amphipod (Rhepoxynius 

abronius) 48-hour LC50 7.9-8.1 F, M 0.332p Knezovich et al., 1996

Estuarine/marine fish

California killifish (Fundulus 

parvipinnis) 96-hour LC50 8.3 F, M 1.43 Bagarinao and Vetter, 1993

Chronic aquatic toxicity

Algae - No data

Freshwater invertebrate

Freshwater amphipod (G. 

pseudolimnaeus)

65-day LOEC 

(reproduction)

Not 

reported F, M 0.0031 Smith and Oseid, 1975 (Table 3)

Crayfish (P. clarkii) 447-day NOEC 

(survival) 7.69-7.73 F, M 0.0041 U.S. EPA, 1976 (Table 106)

Ephemeroptera (H. limbata) –

nymph

138-day NOEC 

(survival) 7.8-8.2 F, M 0.0129 U.S. EPA, 1976 (Table 126)

Freshwater amphipod (G. 

pseudolimnaeus) 10-day LC50k 7.5o F, M 0.0420 Oseid and Smith, 1974b (Table 3)

Freshwater amphipod (G. 

pseudolimnaeus) 18-day LC50k 7.5o F, M 0.0110 Oseid and Smith, 1974a (page 821)

Freshwater fish

Bluegill (L. macrochirus) 97-day LOEC 

(reproduction)

Not 

reported F, M 0.0007 Smith and Oseid, 1975 (Table 3); U.S. EPA, 1976 (Table 59)

Bluegill (L. macrochirus) 97-day LOEC 

(reproduction) 7.6-8.0 F, M 0.0010 Smith et al., 1976a (Table 7)

Bluegill (L. macrochirus) 97-day LOEC (# 

eggs/female)

Not 

reported F, M 0.0014 Smith and Oseid, 1974 (Table 2)

Fathead minnow (P. promelas)

274- to 297-day 

mean NOEC 

(survival)

7.7-7.9 F, M 0.0036 Smith et al., 1976b (Table V)
19

Species Duration and Test 

Endpoint

pH During 

Teste

Experimental 

Typeb,c

Value 

(mg/L)d Reference

Fathead minnow (P. promelas) 56- to 112-day mean 

NOEC (growth) 7.7-7.9 F, M 0.0042 Smith et al., 1976b (Table V)

Fathead minnow (P. promelas)

274- to 297-day 

mean NOEC 

(fecundity)

7.7-7.9 F, M 0.0059 Smith et al., 1976b (Table V)

Fathead minnow (P. promelas)

297-day LOEC 

(adult survival to 

spawning)

Not 

reported F, M 0.0061 Smith and Oseid, 1974 (Table 2)

Fathead minnow (P. promelas) 37-day LOEC 

(survival) 7.67-7.85 F, M 0.0078 U.S. EPA, 1976 (Table 14)

Goldfish (C. auratus) 430-day LOEC (final 

weight) 7.57-7.63 F, M 0.0090 U.S. EPA, 1976 (Table 46)

Freshwater tropical fish (Mystus 

nemurus)

6-week LOEC 

(decreased growth 

rate and decreased 

liver somatic index)

6.9-7.5 F, Mf 0.0005 Hoque et al., 1998 (Table II)

Brook trout (S. fontinalis) – adult 76-day LOEC (# 

eggs/female)

Not 

reported F, M 0.0055 Smith and Oseid, 1974 (Table 2)

Brook trout (S. fontinalis) – adult 120-day LOEC 

(reproduction) 7.78 (mean) F, M 0.0055 U.S. EPA, 1976 (Table 82)

Walleye (S. vitreum vitreum) 225-day LOEC 

(survival) 7.59-7.71 F, M 0.0051 U.S. EPA, 1976 (Table 67)

Estuarine/marine invertebrate 

Sea urchin (Lytechinus pictus)

49-day LOEC 

(decreased wet 

weight)

8.0 F, M 1.121 Thompson et al., 1991 (Figure 

5B)

Estuarine/marine fish

Atlantic salmon (Salmo salar) 18-week LOEC (liver 

damage)

Not 

reported S, M 0.238 Kiemer et al., 1995 (Figure 9)

Early Life Stage Toxicity Testing

Freshwater invertebrate

Crayfish (Procambarus clarkii) –

juvenile 96-hour LC50 7.71 (mean) F, M 0.034 U.S. EPA, 1976 (Table 103)

Freshwater fish

Fathead minnow (Pimephales 

promelas) – eggs

96-hour LC50 7.9 F, M 0.0190 U.S. EPA, 1976 (Table 3)

Fathead minnow (P. promelas) –

eggs

96-hour LC50 7.9 F, M 0.0536 Smith et al., 1976b (Table II)

Fathead minnow (P. promelas) –

eggs

84-day LOEC 

(growth and survival)

Not 

reported F, M 0.0065 Smith and Oseid, 1975 (Table 3)

Fathead minnow (P. promelas) –

swim-up fry 96-hour LC50

Not 

reported F, M 0.0070 Smith and Oseid, 1974 (Table 5); Smith and Oseid, 1975 (Table 2)

Fathead minnow (P. promelas) –

fry 96-hour LC50 7.9 F, M 0.0066 U.S. EPA, 1976 (Table 3)

Fathead minnow (P. promelas) –

fry 96-hour LC50 7.9 F, M 0.0107 Smith et al., 1976b (Table II)

Fathead minnow (P. promelas) –

juvenile 96-hour LC50 7.9 F, M 0.0179 U.S. EPA, 1976 (Table 5)
20

Species Duration and Test 

Endpoint

pH During 

Teste

Experimental 

Typeb,c

Value 

(mg/L)d Reference

Fathead minnow (P. promelas) –

juvenile 96-hour LC50 7.9 F, M 0.0243 Smith et al., 1976b (Table II)

Rainbow trout (Salmo gairdneri) –

eggs

96-hour TL50j 7.6-8.0 F, M 0.0490 Smith and Oseid, 1972 (Table 2)

Rainbow trout (S. gairdneri) –fry 20-day LC50 7.7 (mean) F, M 0.0056 U.S. EPA, 1976 (Table 91)

Rainbow trout (S. gairdneri) –

swim-up fry 20-day LC50

Not 

reported F, M 0.0060 Smith and Oseid, 1974 (Table 5)

Rainbow trout (S. gairdneri) –

juvenile 96-hour LC50 8.0 F, M 0.0070 Fung and Bewick, 1980 (Table 4)n

Rainbow trout (S. gairdneri) –

juvenile 96-hour LC50 7.7 (mean) F, M 0.0125 U.S. EPA, 1976 (Table 87)

Rainbow trout (S. gairdneri) –

juvenile 96-hour LC50

Not 

reported F, M 0.0130 Smith and Oseid, 1974 (Table 5)

Bluegill (Lepomis macrochirus) –

eggs

96-hour LC50 7.8-8.0 F, M 0.0190 Smith et al., 1976a (Table 2)

Bluegill (L. macrochirus) – swimup fry 96-hour LC50 7.8-8.0 F, M 0.0086 U.S. EPA, 1976 (Table 50)

Bluegill (L. macrochirus) – swimup fry 96-hour LC50Not 

reported F, M 0.0090 Smith and Oseid, 1975 (Table 2)

Bluegill (L. macrochirus) – fry 96-hour LC50 7.8-8.0 F, M 0.0131 Smith et al., 1976a (Table 2)

Bluegill (L. macrochirus) – fry 8-day LC50 7.8-8.0 F, M 0.0128 Smith et al., 1976a (Table 2)

Bluegill (L. macrochirus) –

juvenile 96-hour LC50 7.8-8.0 F, M 0.0478 Smith et al., 1976a (Table 2)

Bluegill (L. macrochirus) –

juvenile 8- to 10-day LC50 7.8-8.0 F, M 0.0480 Smith et al., 1976a (Table 2)

Whitefish (Coregonus 

clupeaformis) – sac fry 96-hour LC50 8.0 F, M 0.0020 Fung and Bewick, 1980 (Table 4)n

Yellow perch (Perca flavescens) –

sac fry 96-hour LC50 8.0 F, M <0.0020 Fung and Bewick, 1980 (Table 4)n

Brown trout (Salmo trutta) – sac 

fry 96-hour LC50 7.0-7.2 F, M 0.0070 Reynolds and Haines, 1980 (Table 2)

Walleye (Stizostedion vitreum 

vitreum) – eggs

96-hour TL50j 7.6-8.0 F, M 0.0520 Smith and Oseid, 1972 (Table 2)

Walleye (S. vitreum vitreum) –

eggs

10-day TL50j 7.6-8.0 F, M 0.0220 Smith and Oseid, 1972 (Table 2)

Walleye (S. vitreum vitreum) – fry 96-hour TL50j 7.6-8.0 F, M 0.0070 Smith and Oseid, 1972 (page 

715)

Walleye (S. vitreum vitreum) –

juvenile 96-hour LC50 7.8-8.0 F, M 0.0166 U.S. EPA, 1976 (Table 65)

Walleye (S. vitreum vitreum) –

juvenile 96-hour LC50

Not 

reported F, M 0.0200 Smith and Oseid, 1974 (Table 5)

Northern pike (Esox lucius) – eggs 96-hour TLm

j 7.3-8.0 F, Ml 0.0220 Adelman and Smith, 1970 (Table 

4)

Northern pike (E. lucius) – eggs 13-day TLm

j 7.3-8.0 F, Ml 0.0240 Adelman and Smith, 1970 (Table 

4)

Northern pike (E. lucius) – sac fry 96-hour TLm

j 7.3-8.0 F, Ml 0.0080 Adelman and Smith, 1970 (Table 

6)
21

Species Duration and Test 

Endpoint

pH During 

Teste

Experimental 

Typeb,c

Value 

(mg/L)d Reference

Northern pike (E. lucuis) – sac fry 96-hour LC50

Not 

reported F, M 0.0260 Smith and Oseid, 1974 (Table 5)

Largemouth bass (Micropterus 

salmoides) – sac fry 96-hour LC50 8.0 F, M 0.0110 Fung and Bewick, 1980 (Table 4)n

White sucker (Catostomus 

commersoni) – eggs

96-hour TL50j 7.6-8.0 F, M 0.0280 Smith and Oseid, 1972 (Table 2)

White sucker (C. commersoni) –

eggs

12-day TL50j 7.6-8.0 F, M 0.0190 Smith and Oseid, 1972 (Table 2)

White sucker (C. commersoni) –

fry 96-hour TL50j 7.6-8.0 F, M 0.0130-0.0260

Smith and Oseid, 1972 (page 

718)

White sucker (C. commersoni) –

juvenile 96-hour LC50

Not 

reported F, M 0.0190 Smith and Oseid, 1974 (Table 5)

Brook trout (Salvelinus fontinalis) 

– swim-up fry 96-hour LC50

Not 

reported F, M 0.0216 Smith and Oseid, 1975 (Table 2)

Brook trout (S. fontinalis) –

juvenile 96-hour LC50 7.85 F, M 0.0156 U.S. EPA, 1976 (Table 76)

Brook trout (S. fontinalis) –

juvenile 96-hour LC50

Not 

reported F, M 0.0170 Smith and Oseid, 1974 (Table 5)

Goldfish (Carassius auratus) –

eggs

72-hour LC50

Not 

reported F, M 0.0200 Smith and Oseid, 1974 (Table 5)

Goldfish (C. auratus) – eggs 96-hour LC50

Not 

reported F, M 0.0220 Smith and Oseid, 1975 (Table 2)

Goldfish (C. auratus) – eggs

430-day LOEC 

(growth and survival)

Not 

reported F, M 0.0090 Smith and Oseid, 1975 (Table 3)

Estuarine/marine invertebrate

White shrimp (Metapenaeus 

monoceros) – larvae 48-hour LC50 8.0-8.4h F, M 0.0087 Kang and Matsuda, 1994 (Table 1)

White shrimp (M. monoceros) –

juvenile 48-hour LC50 8.0-8.2i F, M 0.0185 Kang and Matsuda, 1994 (Table 1)

Estuarine/marine fish

Black Sea turbot (Rhombus 

maeoticus) – eggs

24-hour LC100

Not 

reported Not reported 2.9 Ivanov et al., 1976

Terrestrial toxicity and phytotoxicity

Avian species - No data

Terrestrial invertebrate - No data

Plants - No data

a

The lowest experimental endpoint values available from a given study were selected for inclusion in the table. If multiple values 

were available for different organism life stages (e.g., multiple LC50 values for fish eggs, and multiple LC50 values for juveniles) 

within a given study, then the lowest values available for each life stage from that study were selected for inclusion in Table 2-1 

(e.g., lowest LC50 for fish eggs and lowest LC50 for juveniles) except where noted. Endpoint values for fish toxicity tests shorter 

than 96 hours in duration (e.g., a fish 24-hour LC50 value) were not included in Table 2-1. Endpoint values for durations longer 

than 96 hours but shorter than 28 days (for fish) and 21 days (for aquatic invertebrates) were included in the acute toxicity 

sections of Table 2-1. b

For freshwater tests, water hardness was within the accepted range (50-250 mg/L as CaCO3) unless noted otherwise. c

Experiment type: S = static, F = flow-through, M = measured d

mg/L = ppm 

e

Study reports did not always indicate whether reported pH values represented mean values. f

Water hardness was not reported.

g

pH was 8.693, which is outside the accepted range of 6.5-8.0. h

pH was 8.2±0.2, which is slightly outside the accepted range of 6.5-8.0.
22

i

pH was 8.1±0.1, which is slightly outside the accepted range of 6.5-8.0.

j

TL50 or TLm is defined as the median tolerance limit. k

The study duration is less than the 21-day duration that is typical of aquatic invertebrate chronic toxicity studies. l

Water hardness was reportedly 290-300 ppm. mThe chemical may not be soluble enough to measure this predicted effect. n

LC50 values for different life stages of four different fish species were reported. Because of the consistency of these LC50 values 

across fish life stages (all were less than 0.063 mg/L), only the single lowest LC50 value for each species (regardless of organism 

life stage) was included here in Table 2-1. o

This is the pH of the well water used in the test; pH during the actual test was not reported.

p

The study reported the endpoint values as total sulfides, and stated that “the concentration of hydrogen sulfide is approximately 

9-10% of the total sulfide concentration under the conditions of these tests.” Therefore, the value reported here represents 10% 

of the value for total sulfides.

2.2.1. Acute Toxicity. Acute toxicity values are presented in Table 2-1. Acute toxicity values 

(96-hour LC50 values) for freshwater fish ranged from 0.0149 to 0.0448 mg/L. Acute toxicity 

values (96-hour LC50 values) for freshwater invertebrates ranged from 0.02 to 1.07 mg/L. For 

estuarine/marine invertebrates, acute toxicity values (48- or 96-hour EC or LC50 values) ranged 

from 0.01 to 0.332 mg/L. For estuarine/marine fish, a 96-hour LC50 value of 1.43 mg/L was 

available.

2.2.2. Chronic Toxicity. Chronic toxicity values are presented in Table 2-1. Chronic toxicity 

values (37- to 430-day LOECs) for freshwater fish ranged from 0.0005 mg/L (freshwater tropical 

fish Nystus nemurus) to 0.009 mg/L (goldfish). For freshwater invertebrates, chronic toxicity 

values (65-day LOEC, 138- or 447-day No Observed Effect Concentrations [NOECs], 10- and 

18-day LC50 values) ranged from 0.0031 to 0.042 mg/L. For estuarine/marine fish, experimental 

data were available only for Atlantic salmon; for this species, an 18-week LOEC (based on liver 

damage) of 0.238 mg/L was observed. For estuarine/marine invertebrates, experimental data 

were available only for a species of sea urchin; a 49-day LOEC (based on decreased wet weight) 

of 1.121 mg/L was observed.

2.2.3. Early-Life Stage Toxicity Testing. Endpoint values from early-life stage toxicity tests 

are presented in Table 2-1. For freshwater invertebrates, a 96-hour LC50 value of 0.034 mg/L for 
23

juvenile crayfish was observed. For freshwater fish eggs, 96-hour LC50 values (for species 

including fathead minnow, rainbow trout, bluegill, walleye, Northern pike, white sucker, and 

goldfish) ranged from 0.0190 mg/L (rainbow trout and bluegill) to 0.0536 mg/L (fathead 

minnow). Additionally, 10-, 12-, and 13-day median tolerance limits (TLm or TL50) of 0.022, 

0.019, and 0.024 mg/L were reported for walleye, white sucker, and Northern pike eggs, 

respectively, and 84- and 430-day LOEC values (growth and survival) of 0.0065 and 0.009 mg/L 

were reported for fathead minnow and goldfish eggs, respectively. For freshwater fish fry, 96-

hour LC50 values for fry ranged from <0.002 mg/L (yellow perch) to 0.026 mg/L (Northern 

pike). Additionally, 20-day LC50 values of 0.006 and 0.0056 mg/L were reported for rainbow 

trout fry, and an 8-day LC50 of 0.0128 mg/L was reported for bluegill fry. For freshwater fish 

juveniles, 96-hour LC50 values ranged from 0.007 mg/L (rainbow trout) to 0.0478 mg/L 

(bluegill). Additionally, an 8- to 10-day LC50 of 0.048 mg/L was reported for bluegill juveniles. 

For estuarine/marine fish, a 24-hour LC100 of 2.9 mg/L was reported for Black Sea turbot eggs. 

For estuarine/marine invertebrates, 48-hour LC50 values of 0.0087 and 0.0185 mg/L were 

available for white shrimp larvae and juveniles, respectively.

2.2.4. Terrestrial Toxicity and Phytotoxicity. No terrestrial toxicity or phytotoxicity data were 

available. 

2.2.5. Population Effects. No data on population effects were located.

2.2.6. Bioaccumulation Potential. Bioaccumulation in aquatic organisms can be estimated 

using the BCF, which describes the degree to which a chemical can be concentrated in the tissues 

of an organism. Measured BCFs were not located in HSDB; thus, a BCF of approximately 3 was 
24

calculated using EPI Suite v4.0 (U.S. EPA, 2009). Based on the calculated BCF, hydrogen 

sulfide is not expected to bioaccumulate in the tissue of aquatic organisms.

2.3. REFERENCES

Adelman, I.R. and L.L. Smith. 1970. Effect of hydrogen sulfide on northern pike eggs and sac 

fry. Trans. Am. Fish. Soc. 3: 501-509.

Bagarinao, T. & R.D. Vetter. 1993. Sulphide tolerance and adaptation in the California killifish, 

Fundulus parvipinnis, a salt marsh resident. J. of Fish Biology, 42: 729-748.

Broderius, S.J., L.L. Smith and D.T. Lind. 1977. Relative toxicity of free cyanide and dissolved 

sulfide forms to the fathead minnow (Pimephales promelas). J. Fish. Res. Board Can. 34: 2323-

2332.

ECOTOX. 2007. ECOTOX user guide: ECOTOXicology Database System. Version 4.0, 

Released February 2007. Available at: http://www.epa.gov/ecotox/.

Fung, D.K. and P.H. Bewick. 1980. Short-term toxicity of aqueous hydrogen sulfide to 

representative fish species of Lake Huron. In: Aquatic toxicology. J.G. Eaton, P.R. Parrish, and 

A.C. Hendricks, Eds. American Society for Testing and Materials, ASTM STP 707. p. 377-396.

Gopakumar, G. and V.J. Kuttyamma. 1996. Effect of hydrogen sulphide on two species of 

penaeid prawns Penaeus indicus (H. Milne Edwards) and Metapenaeus dobsoni (Miers). Bull. 

Environ. Contam. Toxicol. 57: 824-828.

Hoque, M.T., F.M. Yusoff, A.T. Law, and M.A. Syed. 1998. Effect of hydrogen sulphide on 

liver somatic index and Fulton’s condition factor in Mystus nemurus. J. Fish Biol. 52(1): 23-30.

HSDB (Hazardous Substances Databank) 2007. Part of the National Library of Medicine's 

Toxicology Data Network (TOXNET7). Bethesda, MD. Available at: 

http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB.

Ivanov, V.N., Usenko, T.G. & A.V. Parkhomenko. 1976. Effect of hydrogen sulfide on the 

survival rate of eggs and embryonal mitoses of the black sea turbot. Hydrobiol. J. 12(2): 60-62.

Kang, J.C. and O. Matsuda. 1994. Combined effects of hypoxia and hydrogen sulfide on early 

developmental stages of white shrimp Metapenaeus monoceros. J. Facul. Appl. Biol. Sci., 

Hiroshima Univ., 33: 21-27.

Kiemer, M.C.B., K.D. Black, D. Lussot, A.M. Bullock, and I. Ezzi. 1995. The effects of 

chronic and acute exposure to hydrogen sulphide on Atlantic salmon (Salmo salar L.). 

Aquaculture. 135: 311-327.

Knezovich J.P., Steichen D.J., Jelinksi J.A. & S.L. Anderson. 1996. Sulfide tolerance of four 

marine species used to evaluate sediment and pore-water toxicity. Bull Environ Contam Toxicol 

57: 450-457.
25

Oseid, D.M. and L.L. Smith. 1974a. Chronic toxicity of hydrogen sulfide to Gammarus 

pseudolimneaus. Trans. Am. Fish. Soc. 4: 819-822. 

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