Before entering the area of suspected vapors, two firefighters in full protective gear including Self

Contained Breathing Apparatus, having zero adjusted the CGI (Combustible Gas Indicator) will enter the area taking air samples, as they enters.

WARNING: "DO NOT TOUCH" any electrical circuits. Leave lights on if they are on and leave

lights off if they are off. "DO NOT USE" a portable radio or flashlight in the suspected area.

Once all readings have been taken, the officer will be notified and appropriate actions to be taken.

If readings approach or exceed 10% of the lower explosive limit "EXTREME CAUTION" should be used in continuing the investigation.

WARNING: this meter does not detect toxic environments.

If a reading of 25% or more is obtained on the meter than the atmosphere is considered unsafe for firefighters to work. Evacuation of the area is recommended, following by ventilation of the entire area.

• Is the building supplied with LP gas?
• Are there any open flammable liquid containers in the area?

• If an open flammable liquid container is found, cap it and remove it from the area.

• Is there an open sewer in the cellar or below grade?

• If an open sewer is found cover it and notify the owner.

• Are there any flashing lights in the area, which would indicate an electrical problem?

• If an electrical problem is found notify the owner to call a licensed electrician and turn the effected circuit off.

• If meter pointer goes to extreme right side of scale, when using the CGI meter be very careful to note and change in the pointer.
• If at any time during a test the pointer moves to the extreme right of the scale at or beyond the 100 mark, then you are in an extremely concentrated vapor or gas atmosphere. Remove your self from the area being sure to take more readings as you leave.
• If the pointer goes all the way to the right and then falls back to zero, then the chances are that you are in an area that is above the upper explosive limit and probably in an oxygen deficient atmosphere.