Role Overview

We're looking for a Senior Environmental, Health & Safety Engineer to be Arbor's first dedicated EHS hire. You'll build our safety program across our El Segundo shop and lab, our hot-fire test site in San Bernardino, and the first-of-a-kind power plant we are now engineering. At the test site we run a direct-fired supercritical CO₂ combustion loop on natural gas and oxygen. Today, safety at Arbor is owned by the engineers who do the work. We want to keep it that way while giving them the structure, tools, and expertise to do it well as the team grows.

This is a hands-on engineering role. You'll walk systems down before hazardous operations, sit in readiness reviews, write hazardous-operations procedures alongside the test engineers, and help design the controls that let the team move quickly without trading away safety. You co-sign procedures and readiness reviews; the responsible engineer owns the go decision, and you make sure it's made with hazards understood and controls in place. When something can't be done as planned, we'll look to you to help develop a better plan.

You'll report to the Head of Systems Engineering and split your time between El Segundo and the test site, with more time on site during first-time operations and, later, at our first-of-a-kind plant during construction and commissioning.

Responsibilities

• Build and own Arbor's EHS program: site-specific Injury and Illness Prevention Programs, hazard communication, lockout/tagout (including pressurized and fluid energy), hot work, confined space, electrical safety, contractor control, incident investigation, and the training behind them.
• Formalize test-operations safety with the test team: hazardous-operations procedures, exclusion zones and personnel control, pre-test readiness reviews, and post-test debriefs. Be on site for first-time hazardous operations.
• Lead hazard analyses (JHA, What-If, PHA/HAZOP-style) for new hardware and new operations, and manage change so the analysis stays true as things evolve.
• Bring engineering judgment to oxygen, natural gas, high-pressure CO₂, and cryogenic systems—oxygen compatibility, siting and separation, relief and venting, asphyxiation monitoring—and review designs early so controls are engineered in rather than procedural.
• Lead incident and near-miss investigations focused on learning and closing corrective actions.
• Own the technical side of environmental permitting and compliance (air permitting for combustion test equipment, hazardous-materials inventory and filings, hazardous waste), working with our projects team and outside consultants on the agency-facing side.
• Serve as the safety interface with the test-site host, contractors, and regulators, and carry the program into plant design, construction, and commissioning.

Requirements

• Bachelor's degree in an engineering discipline.
• 5+ years of EHS, process safety, or test safety experience in an environment with hazardous operations—engine or vehicle test, launch, propellants or energetics, chemical or power plant, or industrial gas.
• Hands-on experience with pressurized fluid and gas systems, oxygen, flammable gases, or cryogens, and the hazard analysis methods used on them.
• Experience building or substantially rebuilding a safety program, and writing procedures and hazard analyses that engineers and technicians actually use.
• Working knowledge of Cal/OSHA and federal OSHA requirements and the NFPA codes covering compressed gases, cryogenic fluids, hot work, and electrical safety.
• A track record of getting hazardous work done safely and on schedule, and of earning credibility with engineers who don't report to you.
• Available on site for hazardous operations, including early mornings, extended days, and occasional weekends during test campaigns.

Preferred Qualifications

• EHS or process-safety experience at a rocket engine or vehicle test site, launch site, or first-of-a-kind energy pilot plant.
• Experience as the sole or first safety professional at a site or company.
• Combustion, oxy-fuel, or high-pressure CO₂ system experience; oxygen-system cleaning and materials compatibility practice.
• Safety experience with metal additive manufacturing and powder handling—combustible and reactive metal dust, inert-gas atmospheres, respiratory exposure, and housekeeping controls.
• California environmental permitting experience (air permits for combustion equipment, CUPA programs, hazardous waste); construction and commissioning safety on an industrial project.
• CSP, ASP, CIH, or PE; OSHA 30 or HAZWOPER 40.
• Background in startup environments or first-of-a-kind hardware development.

Compensation & Benefits

• Pre-IPO stock options
• Medical, dental, and vision insurance (Arbor covers 90% for employees)
• Basic life insurance fully covered
• Health savings account (HSA) with matching
• Flexible savings account (FSA)
• Unlimited PTO
• 12+ company holidays, including Earth Day!
• 401(k)
• Commuter benefits
• Annual learning and development stipend
• And more!

Base Pay: $130,000 - $165,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.