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EPA OSC Response site, 2026-10-04

Site: https://response.epa.gov (US EPA Region 9 On-Scene Coordinator site). Found via Google query: Sylmar 2011 explosion "Tylar" OR "Larson" hydrogen oxygen gas company.

Pages read: - POLREP #2: https://response.epa.gov/site/polrep_printer.aspx?counter=16149 (redirects to https://response.epa.gov/sites/7236/files/SSI_polrep_2.htm), dated 9/18/2011, from OSC Robert Wise, reporting period 09/07-09/15/2011. - Site profile: https://response.epa.gov/site/site_profile.aspx?site_id=7236 ("Stategic Sciences - Experimental Fuel Cylinders"; short URL response.epa.gov/SSI). - Not read (next run): POLREP counter=16424 (another POLREP, PDF), POLREP 4, and the Documents list: "CERCLIS Check List for Strateg...", "State request for removal lett...", "October 3, 2011 CERCLA General..." and "October 5, 2011 CERCLA General..." notice letters. A DOT special permit was also to be posted.

What POLREP #2 records [web: POLREP #2 URL above]

Government record, written by an agency with a regulatory stake (it is responding to a hazard). The descriptions of the gas below are the EPA's and its consultants' characterizations. - Explosion on 9 August 2011, about 4:20 p.m., at Strategic Sciences, Inc. (SSI), 12349 Gladstone Avenue, Sylmar, California; two employees severely injured. "SSI formerly conducted business in Simi Valley, California, under the name Realm Industries." Mentions the 2010 Simi Valley fatal explosion and "reports of an additional explosion in Simi Valley in 2008", which it says was apparently not reported. - SSI was producing a gas called "TyLar" gas. The EPA describes it as made by splitting hydrogen and oxygen from water, "highly flammable, shock sensitive", "similar to 'Brown's gas'". - Just before the Sylmar explosion SSI filled three carbon(-steel) cylinders with TyLar gas for shipment to South Korea. An associate drove them to a shipper near LAX, then to a freight forwarder near the Port of Los Angeles (2665 E. Del Amo, Rancho Dominguez). BNX Shipping made shipping papers from the TyLar MSDS, which "states that the material consists of compressed hydrogen gas", while the associate's initial invoice described the cargo as "compressed water vapor". The shipping papers listed both an oxygen-hydrogen mixture and pure hydrogen. - Cal/OSHA and EPA Criminal Investigation Division (CID) investigators called the material static sensitive and highly flammable. Airgas's emergency response organization (AERO) advised that the cylinders could detonate if opened and recommended explosive destruction rather than sampling. CID had originally asked for the cylinders to be sampled; no sample was taken. DOT PHMSA classed them "Forbidden for Transportation". - 15 September 2011: the cylinders were moved under special permit to the San Bernardino Sheriff's training range at Devore and shot with a .308 rifle by FBI and Sheriff's bomb squads. The first cylinder vented without detonating; the second and third detonated and burned; the second shredded and travelled about 200 ft. The OSC observed that the cylinder valves were not rated for flammable gases. The remains were kept as evidence by EPA CID. - A CERCLA General Notice Letter was sent to Strategic Sciences on 14 September 2011. - Site profile summary: three render-safe operations in total, involving cylinders at the freight warehouse and at the Sylmar site.

Bearing on the claims

  • Claim 2 (a stored vapor distinct from electrolysis gas, kept at 1-100 psi for months): the company's own MSDS, as quoted by EPA, called the product compressed hydrogen, and its invoice called it compressed water vapor. No composition analysis exists, because the cylinders were destroyed unsampled. This is an anomaly for the record: the one physical sample that could have settled what TyLar gas was got destroyed for safety reasons.
  • Claim 3 (safer than electrolysis hydrogen; reversion releases energy): the EPA and AERO treated the gas as a detonable fuel-oxidizer mix. Two of three cylinders detonated when shot.
  • Historical record (priority 4): the company kept operating under new names (Realm Industries, then Strategic Sciences, TyLar gas) and was preparing an export to South Korea in August 2011. The Korean buyer is a lead: someone there may have received or tested earlier samples.