What is PETN? What you need to know about the explosive found in UP assembly

The PETN explosive found lying under the seat of a Samajwadi Party MLA inside the UP Assembly is one of the most dangerous plastic explosives available in the black market and preferred by militants as the colourless crystals easily surpass security checks.

The packet, which weighed around 150 g, was found close to the seat of Leader of the Opposition Ram Govind Chaudhary, which is close to the podium where the Speaker sits.
"This is PETN (Pentaerythritol Tetranitrate), this is a dangerous substance," Chief Minister Yogi Adityanath told a stunned House soon after it assembled for the day.
"As informed by experts, 500 gm of this explosive is enough to blow up the House," he said.
PETN is one of the most dangerous plastic explosives which is available in black market, and belongs to the same family as nitroglycerin.

It is preferred by militant groups because it cannot be easily detected owing to its colourless crystals. Majority of explosive detectors use metal detectors, but PETN can be kept hidden in a sealed container or an electrical equipment and thus can easily surpass security checks.

"The dog squad failed to detect the explosive that was found by the cleaning staff on July 12," the chief minister said.
Several countries have severe restrictions on purchase of PETN which can be bought in powder form or thin plastic sheet.
The substance is legally used by the military and in mining industries where it is used in detonators for detonating cords and mines. PETN can be mixed with other chemicals to form Semtex.

PETN before crystallization from acetone (WikiMedia Commons)

Experts say PETN does not go off on its own. The explosive needs a secondary detonating mechanism to produce heat or a shockwave, which can detonate the explosive. The substance is stable and safe to handle, but requires a primary explosive to detonate it.

PETN substance has been used in number of bombing incidents over the years.
Apart from reports of PETN explosives from all around the world, the substance is believed to have been used in the 2011 Delhi High Court blast, in which at least 17 people lost their lives.

How lawmakers reacted to the explosive 

Taking note into the issue of a suspicious white powder packet found in the State Assembly, Uttar Pradesh Minister Shrikant Sharma on Friday said the entire state stands together against terrorism and forces planning such activities will never be successful in their plans.

'The entire matter has been handed over to the NIA, so that the probe could be done properly. The entire country stands united against terrorism and such forces will never be successful in carrying out any such activity in Uttar Pradesh,' Sharma told ANI.

He said whatever decision will be taken by the speaker to ensure security in the Assembly, every member is committed to follow it.

Meanwhile, Bahujan Samaj Party (BSP) leader Mukhtar Ansari referred the incident as very crucial and expressed confidence that the accused will be revealed soon.

'I am sure the matter will be solved because the footage of the entire incident is available in the CCTV camera. Attempt like this has taken place earlier also against me and because of that I am suspecting that a psycho person can take any step,' he said.

Earlier, Uttar Pradesh Chief Minister Yogi Adityanath sought for a National Investigative Agency (NIA) probe into the matter.

Adityanath, while confirming that an explosive, by the name of Pentaerythritol tetranitrate (PETN), was indeed found in the Assembly, pressed for more vigilance in Uttar Pradesh, more particularly in the Assembly and rued the absence of a Quick Response Team (QRT) for the state.

"The packet of the explosive was found under the chair of the Opposition's leader. It was 150 gm of PETN. 500 gm of PETN is enough to blow the whole Assembly off. This shows the severity of the situation. I suggest that everybody present in the Assembly should be investigated by the police and that the NIA should investigate into the matter," he said.

"It's unfortunate that the largest Assembly of the country doesn't have a QRT," he added.

Adityanath also said that this incident could be in connivance with a terrorist or militant group and that the security of the state and the country is paramount.

Aditynath also urged the officials to not compromise on the security of the state and the nation, more so considering the current situation of the country.

Supporting the Chief Minister's assertions, Speaker Mata Prasad Pandey said that the whole Assembly is like a family and that the security cannot be compromised.

He also apprised the members about the new security arrangements in the Assembly.

"There will be a Pradeshik Armed Constabulary (PAC) team at every gate of the Assembly. There will also be a full body scanner at every gate. Moreover, a QRT will also be deployed," he said.