Phil,
> The capped shafts are only some five metres from the manholes, but I am
> unable
> to find anyone who is able to go down the manhole to see what the situation
> is.
> There is a very noticeable smell of H2S coming from the workings which has
> put
> me off!
>
This sounds like an extremely dangerous proposition given the toxicity of
Hydrogen sulphide gas (see below). If injury arose from this enterprise, I
suggest 'duty of care' issues would make the instigators vulnerable to court
action, if not criminal negligence claims.
The chemical profile for hydrogen sulphide, according to the US EPA chemical
inventory, is:
CAS Registry Number: 7783-06-4 EPA CHEMICAL PROFILE Date:
October 31, 1985 Revision: November 30, 1987 CHEMICAL IDENTITY
-- HYDROGEN SULFIDE CAS Registry Number: 7783-06-4 Synonyms:
Dihydrogen Monosulfide; Dihydrogen Sulfide; Hydrogen Sulphide;
Hydrosulfuric Acid; Sewer Gas; Stink Damp; Sulfur Hydride; Sulfureted
Hydrogen Chemical Formula: H2S Molecular Weight: 34.08 SECTION I --
REGULATORY INFORMATION CERCLA (SARA) 1986: Toxicity
Value Used for Listing Under Section 302: Chemical does not meet the
toxicity criteria but because of its high production volume and recognized
toxicity it is considered a chemical of concern. TPQ: 500 (pounds) RQ: 100
(pounds) Section 313 Listed (Yes or No): No SECTION II --
PHYSICAL/CHEMICAL CHARACTERISTICS Physical State: Gas
Boiling Point: -76.59F, -60.33C (*Merck 1976) Specific Gravity (H2O=1):
0.916 at -60C (Liquid) (Weiss 1980, p. 518); 1.54 g/L at 0C (*Merck
1976) Vapor Pressure (mmHg): 20 atmospheres at 25.5 C (*Weast 1979)
Melting Point: -121.9F, -85.49C (*Merck 1976) Vapor Density (AIR=1):
1.19 (*Merck 1976) Evaporation Rate (Butyl acetate=1): Not Found
Solubility in Water: 1 gram dissolves in 242 mL at 20C (*Merck 1976)
Appearance and Odor: Colorless gas with the characteristic odor of rotten
eggs (*Weast 1979; *Merck 1976). SECTION III -- HEALTH HAZARD
DATA OSHA PEL: Ceiling 20 ppm; Peak 50 ppm, 10 minutes
(*NIOSH/RTECS 1985) ACGIH TLV: TWA 10 ppm (14 mg/m3); STEL
15 ppm (21 mg/m3) (*ACGIH 1980) IDLH: 300 ppm (NIOSH/OSHA
1978, p. 112) Other Limits Recommended: NIOSH: 10 ppm 10-minute
ceiling (NIOSH 1987, p. 140). EEGL 10.0 ppm (24 hour) (NRC 1985a,
pp. 55-68). Routes of Entry: Inhalation: Yes (*Sax 1975) Skin: Yes (*Sax
1975) Ingestion: Not Found Health Hazards (Acute, Delayed, and Chronic):
Exposure to very high concentrations causes immediate death (Sax 1984, p.
1552). Also death or permanent injury may occur after very short exposure
to small quantities (*Sax 1975). It acts directly upon the nervous system
resulting in paralysis of respiratory centers (*Casarett 1975). Medical
Conditions Generally Aggravated by Exposure: Not Found SECTION IV --
FIRE AND EXPLOSION HAZARD DATA Flash Point (Method Used):
Not Found Flammable Limits: LEL: 4.3% (*NFPA 1978) UEL: 45%
(*NFPA 1978) Extinguishing Methods: A very flammable gas (*NFPA
1978). For small fires let burn unless leak can be stopped immediately. For
large fires, use water spray, fog or foam (*DOT 1984). Special Fire
Fighting Procedures: Stop flow of gas. Use water to keep fire-exposed
containers cool and to protect men effecting the shut-off (*NFPA 1978).
Keep unnecessary people away; isolate hazard area and deny entry. Stay
upwind; keep out of low areas. Ventilate closed spaces before entering
them. Wear positive pressure breathing apparatus and special protective
clothing. Evacuate area endangered by gas. Move container from fire area.
Stay away from ends of tanks. Withdraw immediately in case of rising sound
from venting safety device or any discoloration on tank due to fire. Cool
containers with water using unmanned device until well after the fire is out.
Isolate for one-half mile in all directions if tank car or truck is involved in fire
(*DOT 1984). Unusual Fire and Explosion Hazards: Compound is heavier
than air and may travel a considerable distance to source of ignition and flash
back. It forms explosive mixtures with air over a wide range. Also reacts
explosively with bromine pentafluoride, chlorine trifluoride, nitrogen triiodide,
nitrogen trichloride, oxygen difluoride, and phenyl diazonium chloride
(*NFPA 1978). When heated to decomposition, it emits highly toxic fumes
of oxides of sulfur (Sax 1984, p. 1552). NFPA Flammability Rating: 4
SECTION V -- REACTIVITY DATA Stability: Unstable: Stable: Yes
(*NFPA 1978) Conditions to Avoid: Avoid physical damage to containers;
sources of ignition; storage near nitric acid, strong oxidizing materials, and
corrosive liquids or gases (*NFPA 1978). Incompatibility (Materials to
Avoid): Incompatible with many materials including strong oxidizers, metals
(NIOSH/OSHA 1978, p. 112), strong nitric acid, bromine pentafluoride,
chlorine trifluoride, nitrogen triiodide, nitrogen trichloride, oxygen difluoride
and phenyl diazonium chloride (*NFPA 1978). Hazardous Decomposition
or Byproducts: When heated to decomposition, it emits highly toxic fumes of
oxides of sulfur (Sax 1984, p. 1552). Hazardous Polymerization: May
Occur: Not Found May Not Occur: Not Found Conditions to Avoid: Not
Found SECTION VI -- USE INFORMATION Used in the manufacturing
of chemicals; in metallurgy; analytical reagent; agricultural disinfectant;
intermediate for sulfuric acid, elemental sulfur, sodium sulfide, and other
inorganic sulfides; additives in extreme pressure lubricants and cutting oils;
and as an intermediate for organic sulfur compounds (*Merck 1976;
*Encyc Occupat Health and Safety 1971; *SRI). Not registered as a
pesticide in the U.S. (USEPA/Pesticide Index 1985). SECTION VII --
PRECAUTIONS FOR SAFE HANDLING AND USE (Steps to be
Taken in Case Material is Released or Spilled) Keep unnecessary people
away; isolate hazard area and deny entry. Stay upwind; keep out of low
areas. Ventilate closed spaces before entering them. Do not touch spilled
material; stop leak if you can do it without risk. Shut off ignition sources; no
flares, smoking or flames in hazard area. Use water spray to reduce vapors.
Isolate area until gas has dispersed. (*DOT 1984). SECTION VIII --
PROTECTIVE EQUIPMENT FOR EMERGENCY SITUATIONS For
emergency situations, wear a positive pressure, pressure-demand, full
facepiece self-contained breathing apparatus (SCBA) or pressure- demand
supplied air respirator with escape SCBA and a fully-encapsulating,
chemical resistant suit. See the introductory information section at the
beginning of the profiles for additional information. SUIT MATERIAL
PERFORMANCE (Based on EPA/USCG "Guidelines", 1987) (Chemical
Resistance/Amount of Data) Butyl GOOD/LIMITED* CPE
GOOD/LIMITED* Neoprene GOOD/LIMITED* PVC
GOOD/LIMITED* *Based on qualitative performance information.
**Based on a chemical analog. SECTION IX -- EMERGENCY
TREATMENT INFORMATION See Emergency First Aid Treatment
Guide
John Penny,
School of Science & Technology,
Bell College,
Hamilton ML3 0JB,
Lanarkshire
Tel: 01698 283100 Ext: 262, fax: 01698 894404,
email: [log in to unmask]
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