How to Find & Fix Sources of Sulphur Odors or Sewer-Gases, Rotten Egg Smells & Hazards in buildings
SULPHUR & SEWER GAS SMELL SOURCES - CONTENTS: What might be causing sulphur odors or rotten egg smells in buildings? List of places to look when diagnosing the cause of sulphur smells or sewer gas smells in buildings
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How to find and fix the source of sulphur odors and smells in buildings:
This article and its companions discusse the common sources of rotten egg odors, sulphur odors or sewer gas smells in buildings and traces them to their possible cause.
Examples of sources of sulfur smells in or around buildings include Chinese drywall outgassing, dangerous sewer gas leaks, plumbing vent defects, sulfur in drinking water, water heater bacteria, and more. We describe safety, explosion, and bacterial hazards associated with sulphur gases and sewer gases in buildings. Our page top photo shows a subtle clue that can explain a sulphur odor in buildings: discolored copper piping on the air conditioner cooling coil caused by outgassing from Chinese drywall.
How to Find & Fix Sources of Sulphur Odors or "Rotten Egg Smells" in buildings Include Smells Associated with Chinese Drywall & Other Causes in buildings
This article series about building odors discusses the diagnosis and cure of odors from a variety of sources including
animals including pets, dogs, cats, or unwanted animals or dead animals, formaldehyde odors in buildings from building products or furnishings, plumbing drains, plastic or vinyl odors from building products, flue gases, oil tanks or oil spills, pesticides,
septic odors, sewer gases, and even abandoned chemicals at properties.
The page top photo of blackened corrosion on an air conditioner cooling coil is from the U.S. CPSC warning to fire safety professionals.
Common Sources of Sulphur Gases & Odors in buildings: Causes of "Rotten Egg" Smells
Sulphur odors in buildings are described also as rotten egg smells or even flatulence smells that generally are associated with the presence of hydrogen sulfide (H2S) gas. To track down and cure the source of such odors review the list below. Information about the gas itself and links to hydrogen sulfide exposure limits and health effects are given separately
at HYDROGEN SULFIDE GAS.
Chinese drywall contamination can produce dangerous sulphur gases and rotten egg smells in buildings that have driven people from homes, caused costly damage, and in some cases cause health concerns as well.
See CHINESE DRYWALL HAZARDS for details about Chinese Drywall problems in U.S. homes. Chinese Drywall outgassing, particularly in homes where drywall was installed in new construction or in remodeling after 2004, creates rotten egg smells & odors, indoor air quality hazards, corrosive outgassing, health hazards, and damage to copper building components such as copper electrical wiring and plumbing - caused by outgassing from Chinese Drywall used in construction in the U.S.
Some buildings using Chinese drywall do not present a characteristic sulphur odor but may still have corrosion and outgassing problems
There are multiple possible sources of sulphur gases and sulphur odors in buildings
Individual sensitivity to odors varies substantially, making odor reports inconsistent, but complaints include headaches, runny noses, and difficulty breathing.
Blocked or improperly installed plumbing vents: see Plumbing Vent Defects for an explanation of sewer gas leaks from building drain vent piping. Transite pipe plumbing vents - an cement-asbestos material, can become delaminated and clogged with age, blocking the plumbing vent system.
See Transite Pipes, Chimneys & Flues
Watch out: if the sulphur odors in a building are due to sewer gas backups, dangerous levels of possibly explosive methane gas could be present. Also, at SEPTIC & CESSPOOL SAFETY we explain that gases produced in a septic tank are dangerous, as a potential source of explosion and as a cause of death by asphyxiation if someone falls into or deliberately enters a septic tank.
Sulphur odors from plumbing traps: Sulphur odors or "septic odors" at a kitchen sink may actually be food odors from a garbage disposer that needs cleaning.
Sulphur odors from a failing or backing-up septic system - see
Dead animals: Other odors mistaken for sulphur odors, such as a dead animal in building walls or crawl spaces. We also mention human flatulence which also can have a sulphur odor but will normally be episodic and brief in duration.
LP Gas or Natural Gas Leak odors: Watch out: some people mistake dangerous, possibly explosive LP gas or natural gas leak odors for sulphur gas or sewer odors.
See Gas Piping and Tank Defects.
In sum, before blaming drywall for building odors, be sure that the smells are not from another detectable source such as sewer gases or a failing hot water tank anode -
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sulphur stains on bathroom shower
Need to know if there is any product or natural way to remove or prevent stains from forming on the bathroom shower. - Anon 10/21/11
Try installing a water treatment system that removes sulphur from the water supply is the most effective and general solution to an odor or sulphur (sulfur) related stain issue. I've found that for light staining on fixtures household cleaners work fine; for difficult stains, products intended to remove iron staining often seem to work well on black sulphur stains as well.
Question: smell in justy one room affects my throat; A/C system circulates it to other rooms
Last summer and again this summer every time we run out certral air conditioning unit there is a smell that permeates only one room in the house. the room above the unit. it is not natural gas becasue PSEand G was here and tested using their detector and found nothing. The smell effcts my throat immediately. The system is cirulating the smell or is it causing the smell. Not everyone can smell it either, sometimes I smell it outside as well around the perimeter of the house, Please advise. Soould I call an air conditioning person or a plumber? - Anne Collins 7/7/2012
Anne I would start with a careful inspection of that section of ductwork feeding the room where you smell the odor as well as the ceiling or wall cavity wherein the duct is routed. Check for a water or plumbing leak, mold, dead animal keep us posted.
Question: sulfur smell from faucet
How do you stop sulfur smell from faucet that is furthest away from water source (well)? The other faucets do not have the smel - Twinlaker 8/24/12
Since the sulfur odor is not, by your account, in the water supply itself, just as you do, I suspect a more local source. If you are dead sure that the smell comes from the water, and not from the building, walls, cavities, etc., nor from a drain in that room, then I suspect bacterial contamination of the plumbing fixtures;
Try shocking the well and through that procedure, the plumbing system in the home. Make sure to let the chlorinated water sit in the piping and faucet overnight, preferably 24 hours.
I have been gone all summer from Arizona and now I'm back how do I get the order to stop coming from the septic tank into my home. - Shirley 10/3/2012
It is not proper nor normal operation for a septic tank to stink. If the odor is coming into your home from outside, the best fix is to inspect and diagnose the problem with the septic tank or drainfield and fix that source. Start your diagnosis at SEPTIC SYSTEM ODORS.
Question: how do we pinpoint the source of a rotten egg odor which comes and goes daily
We have a rotten egg odor which comes and goes daily, It is quite strong in the living room, but we cannot pinpoint it.Can it be coming from the back boiler central heating. /we have also picked up the odor in a kitchen cupboard where the electricity meter is,could something with the wiring be causing it. My husband plumbed in a replacement sink about 6 months ago, and I complained about an odor. He fixed it, but could it be that.It's hard to detect the smell as we start to adjust to it. - Pamsie 10/26/2012
Pamsie, the odor you describe is most often traced to a sewer gas or bad plumbing vent problem - which makes me suspect that the replacement sink may not be properly vented. But it sounds as if you need help tracking down the odor to its source. We provide quite a few suggestions for how to pinpoint an odor source in a separate article titled ODOR DIAGNOSIS CHECKLIST, PROCEDURE.
Question: pungent smell from Coleman split AC system in our trailer - coil cleaning?
(Apr 17, 2014) Dani said:
We have an old Coleman split system HVAC in our trailer. The heater & fan work fine, without odors or problems. But our AC is very weak & after it runs for 10-15 mins, a pungent smell is produced, comparable to brussel sprouts or rotten eggs. We have brand new ducts, as of 6 mos ago. We replaced the filter & cleaned the coils, but the smell still persists. There is no condensation, if that means anything? We are going to go to Home Depot to get some coil cleaner stuff today. We live in Phoenix & we need our AC already! Our trailer heats up fast, our thermostat reads 90 by 2-3pm! Any tips?
If the coil is always in the air path, regardless of whether heating or cooling mode, one would expect that its effect on air flow would also always be present. Look at the evaporator (cooling) coil to see if it is blocked by dirt - if so that could explain weak air flow.
Odors might also be from quite a few other sources in ductwork: dead aninal, overheating electrical components or an odor being picked up from another building location via the return duct system.
Question: odors from leaky Carrier AC system - repairman said airborne sulfur caused leaks
(Nov 23, 2014) Anonymous said:
I bought a new Carrier A/C unit, in only 3 years the evaporator coils went bad and a small leak was detected, I notice some minor surface rust on the coil too. The evaporator coils are covered under warranty. When I questioned the repairman he told me the ONLY thing that can cause this "rapid damage" to evaporator coil is the SULFUR in the air inside my home, the amount of moisture inside my home is drawn into my air-intake and the air mixed with SULFUR acts like a mild acid and destroys the evaporator coils. Yes I do us well water but it runs thru a very expensive and well maintained water purification system, I have no rotten egg smell inside my home and my water smells and feels normal.
1. Does anyone who reads this agree with this mans theory?
2. Do you all think a BIG dehumidifier close to my air in-take will reduce the moisture in the air.
(Nov 24, 2014) (mod) said:
Anon, I would not say ONLY sulphur in this case as there are other sources of corrosion such as Chinese drywall outgassing (discussed also at inspectApedia), swimming pool or other chlorine sources indoors, use of an inappropriate and corrosive cleaner on the coils, and even improper electrical grounding of the equipment.
(Jan 28, 2015) Colleen said:
We live in a rural area, have septic tank outside and underground and the sewage pump is in the basement.The tank is pumped out once a year. The last few years we have been getting sewage smell around the floor and hose holes that go from the sewage pump into the floor and back out to tank.We have different plumbers look at it and cant figure it out, they have inspected tank had camera down drain etc..It seems like it most likely to occur after a few loads of laundry and not all the time.
Last year we had tank pumped and it didn't do it for 9 months, this year it started after a month.When they pumped tank last couple years the basement filled sewer gas, it came from the floor drain in the same room as the sewer pump and it has water in it..Everything seems to drain and flush fine. We notice the vent stack on top the house seems to freeze more often than it did when the house was new it is 13 years old does anyone have any ideas please
From your description it sounds as if slow drains or a failing septic mean that when a fair bit of water runs into the drain the slow drains are causing a push-out of sewer gas from the sewage pump reservoir.
If the vent stack is becoming blocked with frost that to could cause sewer gas (smelly and dangerous) to back up into the building. IN that case it may be possible to fix the problem by installing a larger vent stack up through the roof - when weather permits of course.
Did you ask your plumbers why you need openings from the sewer pump into the room and why the system isn't vented directly to outdoors? And are you saving up to replace the failing septic or broken drains?
Question: floor shakes and sewage smell in new office building
(Feb 16, 2015) Anonymous said:
work in a brand new office building. This building has issue where the floor shakes really bad and the company is working to fix it...while they are fixing that...now all of a sudden it smells like raw sewage in here. It's daily and we are getting no answers from management. should a brand new office have this smell? It's a 4 story building. it's horrible to come to work in this stench.
Anon: this complaint is not one that can be diagnosed by e-text. You need an on-site expert. But I can give an opinion that certainly you should not be smelling sewage gas indoors and that condition could be dangerous.
Question: outdoor air makes my kitchen surfaces and dishware smell like garbage
Apr 21, 2015) Frank said:
when the air from the outside come in my kitchen it makes my glasses,dishes , countertop ,sink, smell like garbage.could it be something in my home that's causing this problem,if I take a glass outside it will begin smelling also
I can't make sense of this question, Frank. You need an on-site expert. First be sure that other people are verifying your complaint independently.
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ASTM E2600 - 08 Standard Practice for Assessment of Vapor Intrusion into Structures on Property Involved in Real Estate Transactions is available from the ASTM at astm.org/Standards/E2600.htm
"This practice is intended for use on a voluntary basis by parties who wish to conduct a VIA on a parcel of real estate, or more specifically conduct a screening evaluation to determine whether or not there is potential for a VIC, and if so, identify alternatives for further investigation."
The standard goes on to emphasize the uncertainty in testing any site for gases and vapor intrusion.
Amoore, J.E. and Hautala, E., 1983. Odor as an aid to chemical safety: odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. Journal of Applied Toxicology 3, 272-290.
Bates, M.N., Garrett, N. and Shoemack, P., 2002. Investigation of health effects of hydrogen sulfide from a geothermal source. Archives of Environmental Health, 57(5): 405-411.
Gangolli, S. (Ed.), 1999. The Dictionary of Substances and their Effects, 2nd edn. The Royal Society of Chemistry. Cambridge.
Sax, N.I. and Lewis, R.J., Sr., 1989. Dangerous Properties of Industrial Materials, 7th edn. Van Nostrand Reinhold. New York.
Snyder, J.W., Safir, E.F., Summerville, G.P. and Middleberg, R.A., 1995. Occupational fatality and persistent neurological sequelae after mass exposure to hydrogen sulfide. American Journal of Emergency Medicine, 13(2): 199-203.
EMS Testing Laboratories (a nationwide chain in the U.S.) - see http://www.emsl.com
"Draft Report on Preliminary Microbiological Assessment of Chinese Drywall", U.S. CPSC, draft report 26 March 2010, - Web Search 08/03/2010, original Source: http://www.cpsc.gov/info/drywall/microbio.pdf
Lori Saltzman, M.S., Director, Division of Health Sciences, U.S. Consumer Product Safety Commission, 4330 East West Highway,
Bethesda, MD 20814, Prepared By: Environmental Health & Engineering, Inc., 117 Fourth Avenue, Needham, MA 02494, EH&E Report #16512,
March 26, 2010
"Drywall Flaws: Owners Gain Limited Relief, Chinese Product Forces Many From Homes", Andrew Martin, The New York Times, p. 1, 18 September 2010
U.S. CPSC & HUD Executive Summary, Chinese Drywall Hazards, published by the US Consumer Product Safety Commission, and supported by the US CDC (Centers for Disease Control), the U.S. EPA (Environmental Protection Agency), and HUD, the U.S. Department of Housing and Urban Development - original source: http://www.cpsc.gov/info/drywall/execsum0410.pdf
Chinese Drywall information hosted by the US Consumer Product Safety Commission, and supported by the US CDC (Centers for Disease Control), the U.S. EPA (Environmental Protection Agency), and HUD, the U.S. Department of Housing and Urban Development - http://www.cpsc.gov/info/drywall/index.html
HUD and CPSC Issue Guidance on Repairing Homes With Problem Drywall, U.S. Department of Housing
and Urban Development, Shaun Donovan, Secretary, Office of Public Affairs, Washington, DC 20410 and U.S. Consumer Product
Safety Commission, 4330 East West Highway, Bethesda, MD 20814, Friday April 2, 2010, HUD No. 10-068 HUD Contact: Shantae Goodloe, (202) 708-0685
http://www.hud.gov/news and CPSC Media Contact: Patty Davis, (301) 504-7908
http://www.cpsc.gov- see http://www.cpsc.gov/info/drywall/hud10068.html for details
HUD and CPSC Issue Guidance on Identifying Problem Drywall in Homes, same source as op.cit., - original source: http://www.cpsc.gov/info/drywall/hud10020.html
FHA-insured families experiencing problems associated with problem drywall may be eligible for assistance to help them rehabilitate their properties. HUD’s Community Development Block Grant (CDBG) Program may also be a resource to help local communities combat the problem.
"Pay up, US tells drywall makers
Government names chinese firms that sold tainted products", William E Gibson, Paul Owers, Sun Sentinel, 26 May, 2010, Palm Beach County FL edition, p. S8. William E. Gibson wgibson@SunSentinel.com - 202-824-8256. Original source: print edition. Online source (less detail) see http://www.sun-sentinel.com/business/
"U.S. names Chinese drywall brands with worst emissions", Los Angeles Times, 27 May 2010 - Web Search 08/03/2010 Original Source: http://www.latimes.com/business/la-fi-drywall-20100527,0,3260498.story
"Chinese Drywall Seller Reportedly Aware Of Problem", CBS4 News, May 20, 2010, Web-Seach 08/03/2010 http://cbs4.com/local/Chinese.Drywall.CPSC.2.1565689.html
CPSC Alert to Fire Safety Professionals - ALERT! Report to CPSC any fires that you suspect are associated with problem drywall - see http://www.cpsc.gov/info/drywall/firesafetyprof.pdf Report problem drywall-related fires to: CPSC’s Rik Khanna at email@example.com or 301-504-7546 or
Andrew Trotta at firstname.lastname@example.org or 301-504-7578.
CPSC Staff Preliminary Evaluation of Drywall Chamber Test Results,
Reactive Sulfur Gases1,
Michael Babich, Ph.D., Mary Ann Danello, Ph.D.,
Kristina Hatlelid, Ph.D., M.P.H., Joanna Matheson, Ph.D.,
Lori Saltzman, M.S., and Treye Thomas, Ph.D.
March 2010 - see http://www.cpsc.gov/info/drywall/chamber0310.pdf
US CPSC Status Update on Chinese Drywall - March 2010 - see http://www.cpsc.gov/info/drywall/mar2010status.pdf
U.S. Federal Drywall Information Center website -
We are aware of complaints and lawsuits related to certain wallboard manufactured in China that was imported into Florida in the 2005-2006 timeframe. All of United States Gypsum Company’s wallboard is produced in North America and does not have the problems associated with Chinese made drywall.
U.S. Gypsum also provides information about its use of synethetic gypsum as follows:
Synthetic gypsum has been used to make wallboard in the U.S. for more than 20 years: Since 2000 alone, the U.S. gypsum wallboard manufacturing industry has produced the equivalent of 72,000,000,000 square feet of wallboard made with synthetic gypsum – enough to finish the interior of more than 7,000,000 American homes. Today, all USG SHEETROCK™ brand gypsum wallboard is manufactured using either synthetic gypsum, gypsum mined in North America, or a combination of both.
Synthetic gypsum is identical to mined gypsum: Synthetic gypsum is an environmentally‐friendly product made through a controlled process by which limestone and water are used to “scrub” the emissions from coal‐fired power plants to create the end product calcium sulfate. Calcium sulfate is a high purity mineral identical in chemical composition to mined gypsum. 1 This “scrubbing” process is also called “flue gas desulfurization” (FGD).
The U.S. Environmental Protection Agency encourages the use of synthetic gypsum in making wallboard: In 1993 and again in 2000, the EPA classified synthetic, or FGD, gypsum as a non‐hazardous waste. The EPA encouraged U.S industry to use FGD gypsum to make wallboard, stating that the use is beneficial to “conserve natural resources, reduce disposal costs, and reduce the total amount of waste destined for disposal.”2 The EPA stated, “[w]e support increases in these beneficial uses, such as . . . use in construction products such as wallboard.”3 As recently as 2008, the EPA highlighted on its website a new wallboard plant that was built near a coal‐fired power plant and would use synthetic gypsum made from scrubbing the power plant’s emissions. ...
- web search 08/03/2010, original source http://www.usg.com/documents/corpcom/synthetic-gyp.pdf
Chinese Drywall information from the Florida state department of Environmental Protection -
http://www.doh.state.fl.us/environment/community/indoor-air/casedefinition.html#presence - help with visual identification of Chinese drywall products.
Chinese Drywall References (from the FL DOH article, these documents can be obtained at www.drywallsymposium.com)
1. Alessandroni, M. What's the (Elemental S)tory?). Poster Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
2. Demott, R., Alessandroni, M., Hayes, H., Freeman, G., Gauthier, T. - Elemental Sulfur and Trace Metal Content in Chinese and Domestic Brands). Poster Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
3. Salazar, R., Krause, D., Eldredge, C. - Comparison of Methods Utilized by Commercial Laboratories for Analyses of Bulk Drywall Samples. Poster Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
4. Singhvi, R, Lin, Y., Admassu, G., Syslo, J. Field Analysis of Elemental Sulfur in Drywall by GC/ECD. Poster Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
5. Spates, W., Rinicker, T., Toburen, T. - Evolution of Chinese Drywall Inspections and Findings Based on Laboratory Data and FDOH Guidelines and the Need to Incorporate New and Productive Inspection Techniques Poster Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
6. Tuday, M., Chen, K, Cherazaie, H., Fortune, A., Henton, W., Parnell, C, Dangazyan, M., Cornett, C. Measurement of Corrosive, Odorous and Potentially Harmful Gases from Imported and Domestic Wallboard . Oral Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
7. Tedder, R. Disposal Options for Imported Drywall. Oral Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
8. Layne, A. EPA’s Activities on Chinese Drywall. Oral Presentation at Technical Symposium on Corrosive Imported Drywall Nov 5-6, 2009.
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