hydrogen sulphide - how toxic is it?
Discussion
Gypsum waste banned from landfill
31 March, 2009
By Thomas Lane
Revised regulations demand isolated waste process to prevent production of toxic gas
New regulations banning gypsum waste from landfill sites will take effect from tomorrow.
Any waste gypsum, which is used to manufacture plaster-based products such as plasterboard, will have to be recycled or deposited in a special cell containing no biodegradable waste within a landfill site.
Previously up to 10% of gypsum was allowed in mixed waste going to landfill sites.
Waste gypsum produces toxic hydrogen sulphide gas when mixed with biodegradable waste. The Environment Agency, which enforces the regulations, said new evidence showed the presence of even very small amounts of biodegradable material mixed with gypsum could result in the production of hydrogen sulphide.
contractors trying to charge more for waste disposal...
31 March, 2009
By Thomas Lane
Revised regulations demand isolated waste process to prevent production of toxic gas
New regulations banning gypsum waste from landfill sites will take effect from tomorrow.
Any waste gypsum, which is used to manufacture plaster-based products such as plasterboard, will have to be recycled or deposited in a special cell containing no biodegradable waste within a landfill site.
Previously up to 10% of gypsum was allowed in mixed waste going to landfill sites.
Waste gypsum produces toxic hydrogen sulphide gas when mixed with biodegradable waste. The Environment Agency, which enforces the regulations, said new evidence showed the presence of even very small amounts of biodegradable material mixed with gypsum could result in the production of hydrogen sulphide.
contractors trying to charge more for waste disposal...
Stability
Stable. Highly flammable. May form explosive mixture with air. Note wide explosive limits. Incompatible with strong oxidizing agents, many metals. May react violently with metal oxides, copper, fluorine, sodium, ethanal.
Toxicology
Highly toxic - may be fatal if inhaled. Inhalation of a single breath at a concentration of 1000 ppm ( 0.1% ) may cause coma. Corrosive when moist. Skin contact may cause burns. There is a rapid loss of sense of smell on exposure to gas concentrations above 150 ppm, and this means that the extent of exposure may be underestimated. Perception threshold ranges from 0.5 ppt to 0.1 ppm. Irritant. Asphyxiant.
Hydrogen Sulphide is a potent chemical asphyxiant, combining with haemoglobin in red blood cells and with intracellular cytochromes and thus rapidly stopping oxygen from access to cellular metabolism (just like gases such as carbon monoxide and hydrogen cyanide). Indeed H2S is arguably as toxic as Hydrogen Cyanide HCN. Biological monitoring or tests for intoxication could be undertaken through spectrophotometry of the haemoglobin in blood.
Hydrogen Sulphide is very foul smelling but very quickly paralyses the sense of smell, and can go on to overcome the victim and eventually cause death. Therefore smell cannot be relied upon to provide warnings of this treacherous gas.
Hydrogen Sulphide is also an irritant of mucous membranes including the eyes and respiratory tract.
Stable. Highly flammable. May form explosive mixture with air. Note wide explosive limits. Incompatible with strong oxidizing agents, many metals. May react violently with metal oxides, copper, fluorine, sodium, ethanal.
Toxicology
Highly toxic - may be fatal if inhaled. Inhalation of a single breath at a concentration of 1000 ppm ( 0.1% ) may cause coma. Corrosive when moist. Skin contact may cause burns. There is a rapid loss of sense of smell on exposure to gas concentrations above 150 ppm, and this means that the extent of exposure may be underestimated. Perception threshold ranges from 0.5 ppt to 0.1 ppm. Irritant. Asphyxiant.
Hydrogen Sulphide is a potent chemical asphyxiant, combining with haemoglobin in red blood cells and with intracellular cytochromes and thus rapidly stopping oxygen from access to cellular metabolism (just like gases such as carbon monoxide and hydrogen cyanide). Indeed H2S is arguably as toxic as Hydrogen Cyanide HCN. Biological monitoring or tests for intoxication could be undertaken through spectrophotometry of the haemoglobin in blood.
Hydrogen Sulphide is very foul smelling but very quickly paralyses the sense of smell, and can go on to overcome the victim and eventually cause death. Therefore smell cannot be relied upon to provide warnings of this treacherous gas.
Hydrogen Sulphide is also an irritant of mucous membranes including the eyes and respiratory tract.
After about 10 ppm for a while I feel a little ill and get a sore throat, above 50 ppm for more than a few seconds and I'll spew (funnily enough, I didn't stand around to see what the exact concentration was). Can't remember what the lethal dose is (should know!)
It will kill you easily enough, and is quite a common cause of death in industrial accidents.
It will saturate into water to make sour water I think, so if you diluted it down enough it'd be ok.
It will kill you easily enough, and is quite a common cause of death in industrial accidents.
It will saturate into water to make sour water I think, so if you diluted it down enough it'd be ok.
I wonder how many of these threads on PH ever get flagged up.
On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
Ask anyone who has worked in an offshore enviroment.
If H2S is likely during drilling operations. Usually BA sets around the installation. Evaction and TSR procedures etc.
I did work with a driller who had to recover at least a dozen bodies from a drillfloor after a H2S blowout back in the late 70's.
If H2S is likely during drilling operations. Usually BA sets around the installation. Evaction and TSR procedures etc.
I did work with a driller who had to recover at least a dozen bodies from a drillfloor after a H2S blowout back in the late 70's.
How toxic is it ? Well it is one of the major concerns when drilling an oil well, if sour gas, H2s, Hydrogen Sulphide is suspected we have breathing aperatus at key sites throughout the rig.
100ppm is sufficient to cause damage to eyes.
Around 200ppm the average person cannot smell it , below that it has a bad egg smell.
800ppm is sufficient to kill.
So how toxic is it ? Very !
100ppm is sufficient to cause damage to eyes.
Around 200ppm the average person cannot smell it , below that it has a bad egg smell.
800ppm is sufficient to kill.
So how toxic is it ? Very !
Sheets Tabuer said:
I wonder how many of these threads on PH ever get flagged up.
On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
Yeah, Blue Peter have got really vindictive after that whole phone-in scandal...On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
Twincharged said:
Sheets Tabuer said:
I wonder how many of these threads on PH ever get flagged up.
On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
Yeah, Blue Peter have got really vindictive after that whole phone-in scandal...On my way to Birmingham childrens hospital today I saw a poster depicting a wheelie bin full of washing up bottles etc with the tag line underneath "A bomb was prevented because his neighbours called the anti terrorist hotline"
Yes, I was always told that hydrogen sulfide gas (as it's now spelt!) is more toxic than hydrogen cyanide gas. However, from my first hand experience it's not fatal in the small concentrations you would encounter it in the lab.
Fortunately (like many sulfides) it has a "rotten egg" smell, which means you won't inhale it for long!
Cyanide on the other hand smells like almonds
We used to do qualitative analysis at school (A level Chem) where you add acid to a metal sulfide, which then gives you the metal salt plus the H2S gas. Not sure this is still allowed!
Fortunately (like many sulfides) it has a "rotten egg" smell, which means you won't inhale it for long!
Cyanide on the other hand smells like almonds
We used to do qualitative analysis at school (A level Chem) where you add acid to a metal sulfide, which then gives you the metal salt plus the H2S gas. Not sure this is still allowed!
Edited by jnm23 on Tuesday 31st March 21:42
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