According to Australian Forklift Training most operators are not aware of the correct way to fit an LP gas bottle to a forklift. When properly fitted, the bottle should be positioned so that the breather or safety relief valve is directly at the top, in the highest position possible.
Untrained operators will usually mount bottles upside down or with the breather in wrong spot. It is important to fit them correctly because there is a vapour space at the top of the bottle. The safety relief valve is supposed to be positioned so that it is inline with this vapour space at all times, so that if the relief valve operates it will release vapour and not liquid.
The liquid can cause nasty burns when in contact with skin as well as causing serious eye damage when in contact with the face. It is recommended that all bottles are only filled to a maximum of 90% capacity so that the top 10% is left for a vapour space. This way if a problem occurs, liquid would not spill out.
Australian Forklift Training also advise the companies to take care of the way the bottles are fitted in order to avoid damage.