# Hydrogen Sulfide

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A draft page for collecting and organizing information, questions, and projects related to hydrogen sulfide, also known as H2S.

Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. It occurs naturally in crude petroleum and natural gas, and can be produced by the breakdown of organic matter and human/ animal wastes (e.g., sewage). It is heavier than air and can collect in low-lying and enclosed, poorly ventilated areas such as basements, manholes, sewer lines and underground telephone/electrical vaults. (via OSHA.gov)

## Framing the problem

We are transferring these questions to the Questions system -- please copy them into a question

• Where is this an issue?
• Who's working on this already?
• What information is missing, if any? How will it change the situation?
• What are they key parameters:
• What intensities & exposure times are harmful to humans or the environment?
• Where and how can it be detected? by smell range?
• How long does it take to detect?
• How fast does it move/change, or how large an area does it affect?
• What kind of detection? presence/absence? direction of flow? intensity or locating a spot source?
• What should the output data look like? Graphs, logs, lights, images?
• What are the data’s uses/outcomes? Legal? Avoidance? Remediation? Regulation?

## Where is this an issue?

Here I've ( @warren ) collected some of the notes folks have posted on PublicLab.org about where H2S has been a problem, under the tag #h2s-sites :

- help build out this list by posting your own notes on H2S-affected sites

## Detecting H2S

Wikipedia's article, which is pretty well referenced, shows that:

0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it.

This seems to be well below what's cited as a risk to health, but OSHA warns not to use smell as a means to detect it (OSHA.gov):

Can be smelled at low levels, but with continuous lowlevel exposure or at higher concentrations you lose your ability to smell the gas even though it is still present. At high concentrations – your ability to smell the gas can be lost instantly. DO NOT depend on your sense of smell for indicating the continuing presence of this gas or for warning of hazardous concentrations.

Most info I've ( @warren ) compiled here shows 10+ parts per million as when health effects are of concern, but one cites a TWA (time weighted average) of 1ppm -- over 8 hours. See below in the health effects section.

### Questions

Some questions about detecting hydrogen sulfide are below.

We are transferring these questions to the Questions system -- please copy them into a question

• What equipment is available today, and who has access to it? How much does it cost and what is its sensitivity/latency? How much does it weigh and how does it work (air grab sample, continuous flow, soil sample?)
• Are there alternative means of detecting which are dramatically different/cheaper?
• silver film tarnishes with exposure to H2S, some sources cite discolored copper coins in someone's pocket as a way to diagnose a high exposure

What are health and environmental concerns for sewage smell in a home? over 1 year ago 3
Is there more information on the "Corrosion Coupon" hydrogen sulfide test kit? about 5 years ago 0
What lab tests are available for hydrogen sulfide, and how much do they cost? about 5 years ago 4
What are different commercially available hydrogen sulfide detection methods? over 5 years ago 3
Does your state have air quality standards for hydrogen sulfide? over 5 years ago 0
Are there occupational exposure rules limiting exposure to hydrogen sulfide? over 5 years ago 1
Are there air quality standards for hydrogen sulfide? over 5 years ago 1
How to select a site for hydrogen sulfide testing? over 5 years ago 3
How can we safely try out and evaluate a hydrogen sulfide test? over 5 years ago 4
What's the best setup for a copper rod or copper plate test for DIY hydrogen sulfide detection? over 5 years ago 6
Can we determine hydrogen sulfide concentration, or a threshold presence/absence using the copper pipe method? over 5 years ago 0
What is the hydrogen sulfide concentration range that can be monitored using a copper tarnish method? over 5 years ago 1
Effective low-cost water filters to remove hydrogen sulfide? over 5 years ago 2
What methods are available for doing air grab samples for hydrogen sulfide? over 5 years ago 2
What are the relative rates of hydrogen sulfide oxidation in ambient air? over 5 years ago 1

## Health effects

Health effects vary with how long, and at what level, you are exposed. Asthmatics may be at greater risk. Low concentrations – irritation of eyes, nose, throat, or respiratory system; effects can be delayed. Moderate concentrations – more severe eye and respiratory effects, headache, dizziness, nausea, coughing, vomiting and difficulty breathing. High concentrations – shock, convulsions, unable to breathe, coma, death; effects can be extremely rapid (within a few breaths).

(Exposure information from OSHA.gov)

Exposure limits from various sources, from an Airgas Materials Safety Data Sheet:

ACGIH TLV (United States, 3/2016).
STEL: 5 ppm 15 minutes.
TWA: 1 ppm 8 hours.
NIOSH REL (United States, 10/2013).
CEIL: 15 mg/m³ 10 minutes.
CEIL: 10 ppm 10 minutes.
OSHA PEL 1989 (United States, 3/1989).
STEL: 21 mg/m³ 15 minutes.
STEL: 15 ppm 15 minutes.
TWA: 14 mg/m³ 8 hours.
TWA: 10 ppm 8 hours.
OSHA PEL Z2 (United States, 2/2013).
AMP: 50 ppm 10 minutes.
CEIL: 20 ppm


Note that these show toxicity at levels close to the ability of the wearable electronic monitors (see above) can detect -- 10-15ppm; "STEL" means Short Term Exposure Limit, or an "acceptable average exposure over a short period of time."

### Existing work on Public Lab.org

A range of projects related to H2S have been developed here over the years; we're going to try to organize it better, but for now:

What are health and environmental concerns for sewage smell in a home? over 1 year ago 3
[Talk Recording] Mobilizing People to Act on Air Pollution with the Bucket Air Monitor - a Community Science Tool almost 2 years ago 1
Response to Alternative Copper Sheet Preparation Method on Public Lab almost 5 years ago 0
Qualitative Time Lapse of Copper Corrosion almost 5 years ago 4
Two Rounds of Copper Rod Test Making almost 5 years ago 3
Copper Strip Test Preparation Using Solvents almost 5 years ago 1
Copper Rod to Copper Sheet Discussion almost 5 years ago 0
Can Bio-char products absorb CAFO gases like Hydrogen Sulfide or Ammonia? about 5 years ago 3
Is there more information on the "Corrosion Coupon" hydrogen sulfide test kit? about 5 years ago 0
What lab tests are available for hydrogen sulfide, and how much do they cost? about 5 years ago 4
How to Help Citizens Affected by Factory Farming? #waterquality #airquality #CAFO #factoryfarms over 5 years ago 0
What are some options for copper materials to make a copper plate test kit? over 5 years ago 3
Help collect environmental sensors + probes on a shared list over 5 years ago 0
What are different commercially available hydrogen sulfide detection methods? over 5 years ago 3
Can you use rubbing alcohol or nail polish remover for prepping copper for Hydrogen Sulfide test? over 5 years ago 16
How to select a site for hydrogen sulfide testing? over 5 years ago 3
How can we safely try out and evaluate a hydrogen sulfide test? over 5 years ago 4
Training in odor identification? over 5 years ago 1
What's the best setup for a copper rod or copper plate test for DIY hydrogen sulfide detection? over 5 years ago 6
Can copper sulfide and copper oxide products be precisely visually identified? over 5 years ago 5
How quickly do copper sulfide and copper oxide form under different environmental conditions? over 5 years ago 0
What is the hydrogen sulfide concentration range that can be monitored using a copper tarnish method? over 5 years ago 1
Copper Sheet Hydrogen Sulfide Detection Activity over 5 years ago 14
Effective low-cost water filters to remove hydrogen sulfide? over 5 years ago 2