Re: Low level natural gas leaks

[Guest guest]

I am curious what types of symptoms have been identified as resulting from low level natural gas expsoures.

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of Jim H. WhiteSent: Thursday, January 31, 2008 11:26 AMTo: iequality Subject: Re: Low level natural gas leaks

and Curtis

Here in the Ottawa, Ontario area I have seen a number of cases of low-level natural gas leaks (often in the furnace or water heater, not the external plumbing) and the occupants were reacting. Because I react strongly as well I am a useful investigator for these situations. Fixing the leaks allows most of these occupants to get better; sometimes very rapidly.

Our gas companies send personnel with the low-sensitivity instruments if not asked to send the few that know how to use (and have) more sensitive instruments. The official position of the industry is that low levels do not cause health problems, but at a practical level they have the better equipment and will find the low-level leaks. It seems best to be firm but non-confrontative and they help. I wonder if other local gas suppliers also have the instruments but will only use them if you ask the 'right' way?

Jim H. White SSC

How can I measure indoor TVOC> > > > > > > Dear Group members,> > > > I would like to ask all members. What is the best and most practical way to > measure indoor TVOC levels?> > > > Is it with a PID unit and the values expressed in isobutylene ?> > > > Is it collection by canister/tube and then sent to a lab where the values are > expressed in Toluene?> > > > Is it by FID ?> > > > The problem is the letter T (Total) a PID does not detect Totals!> > > > I require help on this point as I am involved in a technical commission which > has set the indoor limit at 0.6 mg/m3 expressed in Isobutylene using a 10.6 eV > Lamp!> > > > > > Help very much require for type of equipment required and if possible pros and > cons from people in this area.> > > > Thanks again,> > Gerard > > > > > > > > > >

[Guest guest]

Bob,

The 5 ppm is the total of VOCs detected with the FID. Background (from personal hygiene products, cleaning products, etc.) is often around 1 or two ppm. Using a dual FID/PID instrument, I can pretty well confirm when natural gas is the major constituent. Confirmation typically follows when a gas leak is found and symptoms go away after the repair is completed. If I've got more than 5 ppm on the PID, I'm going to be looking for a source as well, but it won't be the very common natural gas leak.

We finally had to retire our TLV Sniffer - but you are correct that this instrument works very well for sniffing out gas leaks. We also have an OVA 128 that I really loved, but it's no longer supported by the manufacturer so it has joined the TLV in our doesn't-work-but-just-can't-throw-it-away cabinet. Now we use a Thermo Environmental (formerly Foxboro) TVA 1000B. Really good instrument, but be careful not to obstruct the exhaust port located on the bottom side - block it even briefly and the FID will flame out, requiring a re-start. Another minor problem we have experienced is the inlet hose will gradually develop a crack where it connects to the insert fitting on the side of the instrument. This allows air to enter the airstream coming in from the probe, which can significantly lower the reading.

Curtis

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of Bob sSent: Thursday, January 31, 2008 2:15 PMTo: iequality Subject: Re: Spam:Re: Low level natural gas leaks

Curtis,You mentioned 5 ppm. Is this methane? Certainly, not H2S.Is this the level at the pipe fitting? Or concentration in the home?I have used a TLV sniffer to find gas leaks for years. I find it tobe a great reliable instrument.Bob

[Guest guest]

Alice

There are a plethora of symptoms reported to me and experienced by myself to a slight degree during an investigation of a low-level natural gas leak. These symptoms are not unique to the natural gas exposure, but have been observed to disappear when the leak has been stopped:

1 fatigue;

2 a slight headache that can grow to be rehabilitating;

3 irritability;

4 slight nausea not relieved by eating.

Others have reported different symptoms but these are the ones that have been reported to me, or that I have started to experience if I stay close to the leak.

Jim H. White SSC

How can I measure indoor TVOC> > > > > > > Dear Group members,> > > > I would like to ask all members. What is the best and most practical way to > measure indoor TVOC levels?> > > > Is it with a PID unit and the values expressed in isobutylene ?> > > > Is it collection by canister/tube and then sent to a lab where the values are > expressed in Toluene?> > > > Is it by FID ?> > > > The problem is the letter T (Total) a PID does not detect Totals!> > > > I require help on this point as I am involved in a technical commission which > has set the indoor limit at 0.6 mg/m3 expressed in Isobutylene using a 10.6 eV > Lamp!> > > > > > Help very much require for type of equipment required and if possible pros and > cons from people in this area.> > > > Thanks again,> > Gerard > > > > > > > > > >