Watching fires is not a fun

http://www.dailystar.co.uk/news/latest-news/502597/petrol-station-explode-blast-Russia-Dagestan-multiple-dead-natural-gas-firefighters-police

In the video, it is seen, persons walking aside, not knowing the dangers of such fires. Fragments from explosion can travel great distances and can kill the persons. Thermal radiation from fireball also will be felt at longer distances, the overpressure in the form of pressure waves can lift the equipment/persons off the ground, making them to hit other objects and thus get injured/killed.

Fire & Explosion Prevention Strategy in Refineries

Please see the LINK on the above article with download link. The download PDF document lists hazards in LPG bullet area, fireball radius, thermal radiation, probability lethalities, etc

Burn injuries - an article from The Hindu titled "A burning question"

A burning question - The Hindu

LINK

In an article on burn injuries in The Hindu, following are stated:

1. Out of 30 lakh burn injuries every year in India, 10 lakh victims die and most of them are women and children.
2. Burn injuries can be from heat, electricity, chemicals, light or radiation. 
3. First degree burns involve upper skin (epidermis) and need about a week to heal.
4. Second degree burns involve upper skin (epidermis and and portions of dermis), sweat glands, hair follicles, etc leading blister formation, swelling and pain and require two weeks to heal.
5. Third degree burns involve deeper skin, charring the tissues and structures and may require three weeks to heal.
6. Fourth degree burns involve subcutaneous tissue, tendons and even bone damage.
7. Hot air inhaled during fire incidents damage respiratory tract and swelling and lead to complications.
8. Beyond 40 degree centigrade, protein in the skin is coagulated causing tissue destruction.
9. In chemical burns, protein is converted rapidly to salt causing same damage.

Burn injuries also affect psychology of the persons and require care and counselling.

During acid splash, generally persons wash with some water and do their business. But until unless total chemical is washed, it will continue to cause destruction. There can be delayed effects from inhalation of vapors from the dress material that is soaked with the chemicals like HF, phosgene, etc leading to deaths in the sleep.
Alkali burns cause more destruction to eyes even to the extent of blindness.

Therefore, removing the clothes with chemicals, continuous washing for atleast 15 minutes (even then only about 93-95% chemical is washed off) is necessary and this information should be spread among all persons working with chemicals.
In case of flash burns from arc flash, the temperature can be 20000 degree centigrade and can lead to deaths.
Then, immediate treatment to burn victims is also a must. As it gets delayed, damage will be more and chances of recovery will come down. One should know, whom to contact, which hospital to be referred and action should be taken to quickly shift the victim with care.

BLEVE Training Video - Safety Engineering Network (SAFTENG)

A video on BLEVE (boiling liquid expanding vapour explosion) is available at the link below.
BLEVE Training Video Part 1 - EXCELLENT Info - Safety Engineering Network (SAFTENG)
BLEVE Training Video Part 2 - EXCELLENT info - Safety Engineering Network (SAFTENG)

http://www.safteng.net/index.php?option=com_content&view=article&id=1038&Itemid=178 (Part 1)
http://www.safteng.net/index.php?option=com_content&view=article&id=1037%3Ableve-tests-results-1-excellent-info-&catid=52%3Aemergency-response&Itemid=178 (Part 2)
LINK

The video explains about the phenomena of BLEVE, the fire ball radii, the safe distance for emergency responders. We will understand that the safe distance for emergency responders is FOUR times the fireball radius with minimum distance at 90 m. For a 400 lit capacity tank, the fireball radius can be 18 m. We also learn that as the capacity of the flammable storage tank increases by a factor of 10, the fire ball radius doubles. The evacuation distances can be taken as 20 times the fireball radius.

However, these distances are not exact as there are instances of explosion fragments travelling more than 20 times fireball radius. During the incident at New Mexico in 1984, a fragment weighing about 20 T travelled 1200 m.

The water required to cool the exposed hot surfaces 10 lpm/sq.m. It may be noted that inspite of all efforts, if there is whistle/jet engine sound from valves, it is indication of over pressurization inside and all emergency responders should stop their activities and move to safe distances.

Some people assume that BLEVE is possible only with flammable substances. But, as the video explains, BLEVE is possible with any substance that leads to vaporization and pressure rise during external heating/impact and the container rupture leads to BLEVE. Fireball is the result if the substance inside is flammable.

Note: Literature gives following equations:

Fireball radius, R (meters) = 29 M^1/3  where M is mass of flammable in the fireball in tonnes
Fireball duration, t (seconds) = 4.5 M^1/3

Most likely distance for 3^rd degree burns = 80 M^0.42 meters

Maximum distance for 3^rd degree burns = 130 M^0.42 meters

Most likely distance for 2^nd degree burns = 150 M^0.42 meters

Maximum distance for 2^nd degree burns = 240 M^0.42 meters

The heat radiation intensity from the fireball can cause damage to human beings and property. From the literature, it can be seen that 12.5 kw/sq.m heat intensity can be fatal, 8.5 kw/sq.m can cause 1^st degree burns whereas solar radiation gives 0.6 kw/sq.m

BLEVE explanation with video

The following link gives explanation for BLEVE (Boiling Liquid Expanding Vapor Explosion). The explanatory text below states that BLEVE is possible even with nonflammable liquids which should be noted. Many experts differ with this statement and they talk firmly that BLEVE is possible only with flammable substances. Though, the phenomena is same whether it is with flammable or non-flammable substances, I do not understand why some experts in the field differ about BLEVE with non-flammables. If the substance is flammable, then BLEVE is followed with a fireball, else no fireball. Thermal radiation from fireball can trigger secondary fires (domino) if flammables are present nearby.

http://my.firefighternation.com/video/bleve-explanation