UMN

200 Grams of Trimethylsilyl Azide and a Solvent Swap: How a Smith Hall Fume Hood Blew Out Its Windows

Tuesday, June 17, 2014MNhazmatemergency notificationmedium confidence

Confirmed Threat

On the afternoon of June 17, 2014, a fifth-year University of Minnesota chemistry graduate student was burned and cut when his attempted synthesis of trimethylsilyl azide (TMS-azide) detonated inside a fume hood on the fourth floor of Smith Hall. The student had scaled up from published procedures to a 200 g batch and substituted polyethylene glycol (PEG) for the original solvent. The blast shattered all four sides of the fume hood, damaged an adjacent hood, and blew out an exterior window.

Alerts: 3
Response: 7 min
Killed: 0
Injured: 1

Institution

University of Minnesota Twin Cities

Public R1 · MN

~52,000 studentsSAFE-U

Confirmed Timeline

Alert Sequence

3 messages in sequence

Some alert texts below are approximate reconstructions from news coverage, not confirmed verbatim transcripts. Reconstructed texts are shown in italic with a dashed border. Verified verbatim texts have a solid border and are marked accordingly.

INITIAL ALERTSMSJun 17, 2014, 6:07 PM EST

Approximate reconstructionReconstructed from UMN Department of Public Safety SAFE-U alert format and Minnesota Daily reporting on the June 17, 2014 Smith Hall explosion190 chars

SAFE-U Alert: Small explosion in Smith Hall on the East Bank. UMPD and Minneapolis Fire on scene. Avoid the area. One person being treated for injuries. No ongoing threat. Updates to follow.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The University of Minnesota Department of Emergency Management received a 911 call just after 1:00 PM CDT on June 17, 2014 reporting an explosion on Smith Hall's fourth floor

Smith Hall sits on the East Bank of UMN's Twin Cities campus and houses the Department of Chemistry

The SAFE-U system, branded since 2009, is UMN's mass-notification platform; for contained lab incidents the alerts typically went to the building's residents and adjacent buildings rather than the full campus

UPDATEEmailMid-afternoon on June 17, 2014

Approximate reconstructionReconstructed from MPR News and Minnesota Daily reporting on the UMN response to the June 17, 2014 Smith Hall explosion369 chars

Update from UMPD: The explosion in Smith Hall has been contained to a single fume hood on the fourth floor. The injured graduate student has been transported to Hennepin County Medical Center in stable condition. Smith Hall's fourth-floor chemistry labs are closed to all but emergency personnel pending Environmental Health and Safety review. Other floors remain open.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

MPR News reported that the explosion was limited to one lab on Smith Hall's fourth floor and did not include a fire

Hennepin County Medical Center is Minneapolis's regional Level I trauma and burn center

The graduate student, later identified as Walter Partlo, was released from the hospital within days and returned to research the following week

ALL CLEARSMSLate afternoon on June 17, 2014

Approximate reconstructionReconstructed from DCHAS-L incident summary posted by UMN Chemistry chair William Tolman on July 18, 2014199 chars

SAFE-U Update: Smith Hall is safe. The affected fourth-floor laboratory remains closed pending investigation. Other areas have reopened. There is no continuing threat. Thank you for your cooperation.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The DCHAS-L incident summary by Chemistry chair William Tolman became one of the first widely circulated academic lessons-learned reports following the 2010 Texas Tech CSB investigation

The post-incident review identified the solvent substitution from the published procedure to polyethylene glycol (PEG) as a critical hazard the student had not assessed

Tolman's openness about the incident was widely praised as a model for transparent academic incident reporting

Context

Background

On the afternoon of June 17, 2014, fifth-year chemistry graduate student Walter Partlo was working in a fourth-floor lab in the University of Minnesota's Smith Hall when his preparation of trimethylsilyl azide (TMS-azide) detonated inside a fume hood. Partlo had scaled up from a published procedure starting from 200 g of sodium azide and had substituted polyethylene glycol (PEG) for the original solvent because the original solvent had been clumping. The solvent change introduced a critical hazard: PEG is a protic solvent that can react with azide to liberate hydrazoic acid, an explosively unstable compound. The blast shattered all four sides of the fume hood, damaged an adjacent hood, and blew out a window on the building's exterior. Partlo was transported to Hennepin County Medical Center with second-degree burns and glass-laceration injuries; he was released within days. UMN Department of Public Safety issued a SAFE-U emergency alert and Smith Hall's affected floor was closed pending an Environmental Health and Safety investigation. Department chair William Tolman published a detailed lessons-learned report on the DCHAS-L mailing list on July 18, 2014, an unusually transparent academic disclosure that was widely praised in the post-Texas-Tech, post-Sangji era of lab safety reform. The incident generated safety alerts at peer institutions including the University of Notre Dame.

Analysis

Key Findings

The proximate cause was a scale-up combined with an undocumented solvent substitution; the underlying cause was lack of hazard awareness about how PEG could react with the azide intermediate to form explosive hydrazoic acid

UMN Chemistry chair William Tolman's decision to publish a detailed lessons-learned summary on DCHAS-L set a new transparency standard for academic lab incident disclosure in the wake of the Texas Tech CSB investigation

The SAFE-U system, which had been the model for UMN emergency notification since 2009, was activated within minutes; the building reopened the same evening

Outcome

Graduate student Walter Partlo was transported to Hennepin County Medical Center with second-degree burns and lacerations from flying glass; he was released within days and returned to work the following week. No other personnel were injured. The University of Minnesota Department of Chemistry, led by chair William Tolman, conducted an internal investigation and disseminated a detailed lessons-learned report through the DCHAS-L mailing list and the CSHEMA community. The incident prompted a department-wide review of standard operating procedures for azide chemistry and informed lab safety practice nationally.

Provenance

Sources

Student Paper
Smith Hall explosion injures one (Minnesota Daily, June 17, 2014)
mndaily.com
News
Small explosion at U lab leaves grad student with serious burns (Star Tribune)
startribune.com
News
U of M chemistry lab explosion injures one (MPR News)
mprnews.org
Report
Trimethylsilyl azide explosion and injury incident at University of Minnesota (DCHAS-L, William Tolman)
ilpi.com
Source
Trimethylazide lessons learned (UCSD Chemistry safety page)
www-chem.ucsd.edu
Report
Safety Alert: University of Minnesota Lab Accident (Notre Dame Risk Management)
riskmanagement.nd.edu
Official
SAFE-U Emergency (UMN Department of Public Safety)
publicsafety.umn.edu

Alert Sequence

Background

Key Findings

Sources

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