Safety Case
Reactivity Rocket Project · Year 10
The hard rule
Any development of devices combining heat and pressure is fabricated and tested by a licensed professional firm. Students view firing trials by video at a safe distance only.
This rule collapses the school-side safety case to standard Stage 5 chemistry plus one atmospheric flame demo, plus a single teacher-controlled 35% H₂O₂ demonstration in the fume cupboard. Items deferred from earlier drafts (H₂ as fuel, mixed gas storage, in-school combustion chamber, bolted-laminate hot-fire) remain out of scope. 35% H₂O₂ is back in scope as a teacher-only demonstration only (see SOP-03).
Scope and constraints
This program runs in a school chemistry laboratory with a glass-fronted fume cupboard, a Trotec laser cutter (plastics only), and natural-gas or 9 kg LPG cylinder access. At-school chemistry runs at standard school concentrations only (3-6% H₂O₂ if used; 1 M HCl; 1 M NaOH; standard Mg ribbon).
No flight testing. All test articles are static.
No solid propellants. No KNO₃/sugar candy. No perchlorates. No metal fuels beyond a 5 mm Mg ribbon for the pop-test demonstration (qualitative H₂ identification only).
No hydrogen as fuel. Electrolysis is not in scope.
35% H₂O₂ is in scope as a teacher-only demonstration. Students run the rates lab at 3% and 6% (drugstore-grade) and extrapolate to 35%. The teacher then dispenses one 35% aliquot, runs a Walter-rocket-style catalysed decomposition demonstration in the fume cupboard, and the Rocket Chemistry team records the measurement to reconcile against their extrapolation. Students never handle 35% stock. See SOP-03.
No student combustion chamber. The plastic Trotec form study has no combustion role — gas flow only, with ignition (if any) at the nozzle face downstream of the plastic.
Pressurised combustion is off-site, vendor-licensed, observed by video only.
PPE — universal at school
- Splash goggles — always
- Lab coat — closed-front, sleeves down, buttoned
- Closed shoes — no canvas, no open toe
- Nitrile gloves for any acid, base, or H₂O₂ handling
- Long hair tied back
Risk register
| ID | Hazard | Likelihood | Severity | Risk | Controls | Owner |
|---|---|---|---|---|---|---|
| R-01 | 35% H₂O₂ skin contact | Low | Medium | Low | Teacher-only dispensing; nitrile gloves (NOT latex); splash goggles; lab coat; eyewash within 3 m; pre-measured aliquots; students at 2 m line | Teacher |
| R-02 | 35% H₂O₂ + organic ignition (paper, rags, PLA) | Low | High | Medium | No organics within 1 m of rig; brown HDPE storage bottle only; spill = water dilution only, never paper towel | Teacher |
| R-03 | KMnO₄ + 35% H₂O₂ runaway in vessel | Low | Medium | Low | Drip-feed catalyst via separating funnel; max 50 mL aliquot; reaction in borosilicate flask | Teacher |
| R-04 | LPG flashback | Low | Medium | Low | Flashback arrestor inline between gas tap and rig; ignite at nozzle face only; rig in fume cupboard with sash down | Test Director |
| R-05 | LPG leak in fume cupboard | Low | Medium | Low | Pre-ignition soap test on all joints; fume cupboard extraction running; gas tap closed when not in use | Test Director |
| R-13 | Trotec plastic edges + offcut burrs | Medium | Low | Low | Goggles when handling; deburr station before assembly; vacuum laser bed before transfer | Manufacturing SO |
| R-15 | Phase 3 vendor governance failure | Low | High | Medium | Written vendor spec + DFM sign-off + signed telemetry agreement + named licensed operator before any pressurised burn; phase-transition-gate.yaml satisfied | Teacher |
| R-16 | Mg + HCl H₂ evolution (pop test only) | Low | Low | Low | Vented test tube; max 5 mm Mg ribbon per test; bunsen splint ignition is the deliberate test (this is the experiment), not an accidental hazard | Rocket Chemistry SO |
| R-17 | 1 M HCl or 1 M NaOH skin contact | Low | Low | Low | Nitrile gloves + goggles; eyewash within 3 m; standard Stage 5 procedure | Rocket Chemistry SO |
| R-18 | 3% / 6% H₂O₂ student handling | Low | Low | Low | Nitrile gloves + goggles; standard Stage 5 procedure | Rocket Chemistry SO |
| R-19 | Calorimeter hot water + open flame | Low | Low | Low | Standard Year 10 calorimetry SOP; thermal gloves for handling; flame only inside fume cupboard | Rocket Chemistry SO |
R-14 (crowding around fume cupboard) is managed by normal school risk assessment — same as any flame demonstration; no project-specific control needed beyond standard practice.
Note: this register is materially smaller than the v0.1 / v0.2 drafts because of the hard rule (no heat + pressure at school). The items that did stay out of scope after v0.3 are:
- Mixed H₂/O₂ gas (not used — H₂ is not a fuel in this project)
- In-chamber combustion at school (the plastic form study has no combustion role)
- Electroplating (replaced by qualitative galvanic-series demonstration)
- Bolted hot pressure vessel (no in-school combustion chamber)
35% H₂O₂ is back in scope as a teacher-controlled single demonstration in v0.3 — R-01/02/03 cover it. It is the calibration point students extrapolate to from their 3-6% measurements.
Standard Operating Procedures (SOPs)
SOP-01 Atmospheric LPG flame demo (TA-01 brass rig + TA-02-plastic form study)
The atmospheric flame demo is the only ignition event at school. The flame burns at the nozzle face, downstream of the plastic form study. The plastic chamber sees gas flow only — no internal combustion.
Before run: 1. Fume cupboard extraction on, sash down to viewing line. 2. Rig clamped on load cell, gas tube connected via flashback arrestor. 3. Pre-ignition leak check: brush all joints with soapy water; confirm no bubbles with gas flowing at minimum. 4. Eyewash and CO₂ extinguisher within 3 m, charged. 5. Igniter (long match or piezo lighter on extension wand) within reach of the teacher. 6. Goggles on; class behind the 2 m line marked on the floor.
During run: 7. Teacher opens gas tap to set flow rate (~0.5 L/min LPG). 8. Wait 3 seconds for purge, then ignite at nozzle face. 9. Recorder logs load cell for ~5 s. 10. Teacher closes gas tap. 11. Confirm flame extinguished before sash is raised.
Abort criteria: - Any flame visibly upstream of the nozzle face (rare; flashback) - Any plastic component visibly deforming - Any gas smell with the tap closed
SOP-02 H₂O₂ / KMnO₄ rates calibration lab (student work, TA-03)
Quantitative rates measurement at student-safe concentrations. Three calibration experiments — [H₂O₂], [KMnO₄], and temperature.
Before run: 1. Fume cupboard extraction on, sash at viewing line. 2. 250 mL borosilicate Erlenmeyer flask clamped vertically with delivery tube to inverted graduated cylinder over water trough. 3. KMnO₄ solution (per experiment matrix) loaded into separating funnel above flask. 4. Eyewash and water-spray bottle within 3 m, charged. 5. Pre-measured 50 mL H₂O₂ aliquot (3% or 6% per experiment matrix) poured into flask. 6. Goggles + nitrile gloves on; class at 2 m line during the run.
During run: 7. Drip-feed KMnO₄ at 1 drop/s. 8. Recorder logs gas volume every 10 s for 60-180 s. 9. Stop drip if flask base feels warmer than ambient by >5 °C (touch-test, gloved).
Variables (per experiment design, see Rocket Chemistry charter): - Experiment 1: [H₂O₂] at 3% and 6% - Experiment 2: [KMnO₄] at 0.05, 0.10, 0.20, 0.40 M - Experiment 3: Temperature at 15, 25, 35, 45 °C (water bath)
After run: 10. Decant flask to labelled waste bottle. 11. Rinse flask with water; final rinse to waste.
Spill: flood with water immediately; never use paper towel; alert teacher.
SOP-03 35% H₂O₂ teacher demonstration (Walter-rocket cup)
This is a teacher-only demonstration. Students observe from the 2 m line. Purpose: provide a measured 35% data point for the team’s calibration extrapolation reconciliation.
Before run: 1. Fume cupboard extraction on at maximum; sash down to glass viewing line. 2. Identical borosilicate flask + separating funnel rig as SOP-02, but wider gas-collection tube to handle higher flow. 3. 35% H₂O₂ aliquot (50 mL maximum) dispensed by teacher from stock bottle into flask. Teacher only opens the oxidiser cabinet, measures aliquot, and transfers. 4. KMnO₄ solution at 0.10 M in the separating funnel. 5. Eyewash, water-spray bottle, CO₂ extinguisher within 3 m. 6. No paper towels, gloves, or organic-fibre material within 1 m of the rig — pure O₂ + heat can ignite organics. 7. All students confirmed behind the 2 m line, goggles on.
During run: 8. Teacher drips KMnO₄ at 0.5 drop/s initially; can increase if reaction is stable. 9. Recorder (Rocket Chemistry team member, at 2 m line) logs gas volume every 5 s. 10. Reaction will be vigorous: hot steam + O₂ jet. This is expected. 11. Stop drip if flask shows any sign of mechanical stress (whistle, crack, base flex) or if temperature visibly exceeds ~120 °C (steam-pressure venting).
After run: 12. Wait 5 minutes for cool-down with sash down. 13. Teacher disposes of residual: dilute 10:1 with water before drain, pH-test, neutralise with NaHCO₃ if needed. 14. Rocket Chemistry team receives the measured rate and compares against their extrapolated prediction (RC-D5).
Abort criteria: - Any flask deformation, whistling, or vapour leak - Any organic material visibly close to the rig - Any student forward of the 2 m line - Any unfamiliar smell other than ozone (a slight ozone smell is normal)
SOP-04 Mg + HCl pop test (qualitative H₂ identification only)
This is a 10-minute demonstration. Not a rates measurement.
- Standard test tube; ~10 mL of 1 M HCl.
- Small piece of Mg ribbon (~5 mm) dropped in.
- Cover the mouth of the tube with a thumb for ~10 s to collect H₂.
- Bring a lit Bunsen splint to the tube mouth; a sharp “pop” confirms H₂ identification.
- Discuss: this is the same gas you’d produce by electrolysis of water, but at a thousand-times-smaller scale. The pop is the recombination synthesis reaction. Not a propellant in this project.
SOP-05 Ethanol / methane calorimetry (TA-06)
Standard Year 10 calorimetry.
- Pre-weighed ethanol burner or LPG cylinder (regulator-controlled).
- Aluminium beaker with 200 mL water on a tripod inside the fume cupboard.
- K-type thermocouple in water; Arduino + MAX31855 amp + laptop logger.
- Bunsen-style flame heating water for 60-90 s.
- Record water mass, initial T, final T; compute Q = m·c·ΔT.
- Re-weigh burner to get fuel mass consumed; compute P = Q/Δt.
- Compare to literature LHV (ethanol 26.8 MJ/kg; methane 50.0 MJ/kg).
Risk: R-19 — hot water, open flame, standard controls.
SOP-06 Standalone HCl-NaOH titration (TA-05)
Standard Stage 5 titration. No project-specific control beyond normal practice.
- Pre-prepared 1 M HCl in burette.
- 25 mL of 1 M NaOH in conical flask with phenolphthalein.
- Titrate to endpoint.
- Record volume; compute equivalent.
- Discuss conceptual link to exhaust-gas scrubbing (pad water-spray neutralises NOₓ; industrial flue-gas scrubbers neutralise SO₂ with limestone slurry).
SOP-07 Phase 3 vendor burn — observation only
Not a school SOP. The vendor runs the burn per their licensed operation. This entry exists to record that:
- Students do not attend in person
- Telemetry CSV + MP4 video are delivered to the teacher by the vendor
- The teacher reviews telemetry before sharing with students
- Reconciliation against prediction is the Heat Exchanger team’s lab report 4 deliverable
The vendor’s safety case is their own and is not reproduced here.
Emergency procedures (at school)
Chemical splash on skin or eyes: 1. Flood with water (eyewash or sink) for ≥10 minutes. 2. Remove contaminated clothing while flushing. 3. Notify teacher immediately; document for incident report.
Fire in fume cupboard during LPG demo: 1. Close gas tap (master cutoff in cupboard). 2. Lower sash fully. 3. CO₂ extinguisher on standby; teacher-operated only. 4. Evacuate to muster point if not contained in 30 s.
Suspected leak: 1. Close gas tap. 2. Sash down. 3. Extraction at maximum. 4. Wait 10 min; do not ignite anything. 5. Re-test with soapy water.
Sign-off
This safety case is in DRAFT and requires:
For Phase 3 (off-site vendor burn), additional gates apply — see phase-transition-gate.yaml.
No at-school chemistry experiments (W2L5 onwards) until the first four boxes are checked.
References
- NSW Department of Education Chemical Safety in Schools package
- Australian Chemistry Education Sciences (ACES) school lab safety guide
- Safety Data Sheets for: 3% / 6% / 35% H₂O₂, KMnO₄, 1 M HCl, 1 M NaOH, Mg ribbon, CuSO₄, ethanol, phenolphthalein
- Trotec operator manual + school induction record