This comment links to an archived presentation by Tesseract "The space transportation company offering revolutionary propulsion" says on slide 8:

Timing is right

  • Small satellite constellations are reshaping the industry
  • 1st wave: Earth observation
  • 2nd wave: Telecom mega-constellations
  • No affordable propulsion available
  • EU banning toxic propellants in 2020


  1. Is the EU really banning the use of toxic propellants in 2020?
  2. Is the ban only on use within the EU geographically, or by all EU companies independent of launch site or location where the propellant is introduced into the satellite (i.e. where the spacecraft or launch vehicle is fueled)?
  3. How toxic do they have to be to be banned? You can't breathe much hydrogen or methane without getting into serious trouble, and technically oxygen is toxic under extreme circumstances as well.

enter image description here click for full size

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    $\begingroup$ Good question. I'm curious to know if deep-space probes are covered. It's not like they would be polluting the Earth. $\endgroup$
    – DrSheldon
    Aug 2, 2019 at 5:24
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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage
    Aug 2, 2019 at 17:29
  • $\begingroup$ @DrSheldon I have added explicit information that REACH applies to French Guiana / the EEA. $\endgroup$
    – Polygnome
    Aug 3, 2019 at 9:22
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    $\begingroup$ I'm not sure that quibbling over toxicity is really relevant here - hydrazine, a common propellant and germane to this question, is unequivocally toxic and requires incredibly careful handling to avoid loss of life. $\endgroup$
    – Dancrumb
    Aug 3, 2019 at 20:22

3 Answers 3


It's important to address two things: space flight is a tiny fraction of what these chemicals are used for, and nearly all mono-propellants are extremely hazardous to humans and like to spontaneously combust. This isn't a ban on "toxic propellants". It's a ban on an extremely dangerous and toxic chemical of which the aerospace industry uses a tiny portion.

I'll use hydrazine, a common propellant, as an example.

Its primary uses are water treatment, pharmaceuticals, polymers, and agrochemicals. Space flight uses a tiny fraction.

The EU space industry uses about 20 tons of hydrazine annually, mostly for satellite propulsion... The substance is manufactured outside Europe and brought in for purification and further refinement. Over 120,000 tons of hydrazine are manufactured globally every year. The majority is used as a foaming agent in the chemical industry. - Space News: Hydrazine ban could cost Europe’s space industry billions

Since the space industry uses such a tiny fraction, and its very restricted in its replacements, it's likely they will get an exception to continue using it until they develop something better.

As to the tongue in cheek comments like "technically oxygen is toxic", hydrozine is nasty stuff.

It's corrosive, carcinogenic, and toxic to humans. You can be exposed by breathing it, ingesting it, through the eyes, or through your skin. If you smell it you're already exposed. Tiny quantities attack the nervous system, liver, and kidneys. You need a full breathing apparatus to work with it. While it breaks down quickly in air, it lingers in water and soil.

It's highly energetic and hypergolic with many substances meaning it will spontaneously ignite when it comes into contact. That makes it a great choice as a propellant for things like maneuvering thrusters which have to reliably reignite many times and store lots of energy in a small space. But it makes it very dangerous to work with.

There are advantages for space flight, beyond general safety and the environment, to removing toxic, volatile substances from their spacecraft. Having hydrazine on board your space craft means ground crews handling the spacecraft must get suited up in protective gear with their own air supplies and follow careful safety procedures. This is slow and costly.

If there's a leak or explosion, toxic substances can be spilled downrange. This requires additional costly safety and cleanup measures over a wide area. Similarly if a spacecraft must be de-orbited the question of whether its toxic substances will burn up or reach the ground must be considered.

"Green" propellants remove the need for these extreme safety measures. While it's not hard to make a propellant safer than things like hydrazine, the challenge is finding a propellant as reliable, energetic, and stable at a reasonable cost. And it seems they've been found.

NASA is testing hydroxylammonium nitrate in space. Due to its higher specific impulse and higher density it is expected to perform 50% better than standard propellants. And it can be allowed to freeze whereas hydrazine must be kept liquid. LMP-103S has been tested gets about 30% better performance.

Spacecraft are limited in size as well as weight. They need propellant for station keeping and maneuvers. Better performance for a given volume means...

the satellite can either be fitted with a smaller tank, or the mission duration can be extended while retaining the same tank size.

See Also

  • $\begingroup$ What does your last sentence "gets about 30%" mean? Also, I don't see where you are actually answering the question "Is the EU really banning toxic propellants..." $\endgroup$ Aug 2, 2019 at 22:45
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    $\begingroup$ @OrganicMarble if you look at my three numbered questions I think this addresses at least some of them in a helpful way. $\endgroup$
    – uhoh
    Aug 2, 2019 at 22:49
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    $\begingroup$ @OrganicMarble 30% better performance. This is a supplement to the other answers, they answer the direct question just fine. It brings in important context to counter the "health and safety gone mad" attitude of the question and comments. I started with a comment and it ballooned. $\endgroup$
    – Schwern
    Aug 2, 2019 at 22:50
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    $\begingroup$ @PeterMortensen along with a few small but at least not-unhelpful proposed edits, all those changes in the way linking is done clearly conflicts with the authors preference. It can be done either way. The way the author did it is also the way I do it now and I find it much easier to maintain my posts like that. I think reconfiguring other peoples post in that way is heavy-handed and not helpful. $\endgroup$
    – uhoh
    Aug 5, 2019 at 0:05
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    $\begingroup$ @PeterMortensen I appreciate the grammar fixes and attention to detail, thank you. But I prefer the inline link style. $\endgroup$
    – Schwern
    Aug 5, 2019 at 0:41

I think this is due to the SpaceNews article Hydrazine ban could cost Europe’s space industry billions from October 25th, 2017.

Dawn Aerospace also mentions the article on their site for green propulsion:

The current methods of satellite propulsion will not be tolerated much longer, with the European Union planning to ban Hydrazine by 2021. Our green bi-propellant thrusters are a full and complete replacement. Experience hydrazine-like thrust, without the hazard and expense.

The last official stance of the EU commision on the question of Hydrazine I could find is this answer to a parliamentary question from 2016:

Several chromium (VI) compounds are identified as substances of very high concern (SVHC) under the REACH Regulation(1) due to their carcinogenic, mutagenic and/or reprotoxic properties and are included in the list of substances subject to authorisation (Annex XIV to REACH). In order to be able to continue using them, manufacturers, importers and downstream users will need to obtain an authorisation.

As part of the Regulatory Fitness and Performance Programme initiative, the Commission will streamline and simplify the authorisation application procedure under REACH in order to increase the predictability of the process for companies and reduce the administrative burden.

The review period for each authorisation is set on a case by case basis, taking into account all relevant information including the risks arising from the use of the substance, the socioeconomic analysis and the analysis of the alternatives submitted in the application dossier as assessed by the scientific committees of the European Chemicals Agency (ECHA).

Hydrazine was identified as SVHC in 2011, due to its carcinogenic properties, and included in the ‘candidate list’. To date it has not been recommended by ECHA for inclusion in Annex XIV.

As long as hydrazine is not included in Annex XIV to the REACH Regulation, the authorisation requirement does not apply to that substance. Therefore, questions about the applicability of specific exemptions to certain space-related uses are of limited practical relevance. The Commission will respond to the issues raised by the European Space Industry, as soon as an agreed interpretation of the relevant provisions of REACH has been reached among the Commission and the Member States.

In short: Hydrazine is on the candidate list for a ban inside the EU since 2011 but not yet banned. Article 4 of REACH says:

Pursuant to the implementation plan adopted on 4 September 2002 at the Johannesburg World Summit on sustainable development, the European Union is aiming to achieve that, by 2020, chemicals are produced and used in ways that lead to the minimisation of significant adverse effects on human health and the environment.

This might explain the 2020 date.

Furthermore, REACH applies in French Guiana, according to the document Overview of current status of REACH and other International Environmental Regulations and how they are impacting the Space Sector including EEE part (PDF)

Applies directly in entire EU/EEA (incl. French Guiana, excl. CH)

Information of the ECHA reinforces the geographic nature of REACH:

To comply with the regulation, companies must identify and manage the risks linked to the substances they manufacture and market in the EU.

Further reading:

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    $\begingroup$ @DrSheldon The whole thing is about the handling of Hydrazine in the EU. Therefore I would assume if the handling of the fuel is done outside of the EU (Kourou, USA, etc.) the regulations do not apply. The EU has strict rules about working conditions but they don't enforce them in the outsourced factories of European companies (e.g. Bayer, H&M, etc.) $\endgroup$
    – GittingGud
    Aug 2, 2019 at 5:33
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    $\begingroup$ French Guyana is run more or less as a department of France, so EU regs may still apply there. $\endgroup$
    – Hobbes
    Aug 2, 2019 at 7:39
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    $\begingroup$ @Hobbes From wikipedia "French Guiana is an overseas department and region of France" "Fully integrated in the French central state in the 21st century, Guiana is a part of the European Union, and its official currency is the euro." The less seems to be very small. $\endgroup$
    – Uwe
    Aug 2, 2019 at 8:05
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    $\begingroup$ @GittingGud Kourou is inside of the EU, they are voting for members of the European parliament. $\endgroup$
    – Uwe
    Aug 2, 2019 at 8:24
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    $\begingroup$ @GittingGud It's not a hard ban, (see the wikipedia links above) you just have to get permission. $\endgroup$ Aug 2, 2019 at 9:50

Yes, the EU is aiming to end the use of hydrazine by ~2020. This has been in motion since about 2011.

ESA's strategy do deal with this consists of two parts:

  1. they're trying to get an exemption,
  2. they're working on alternatives, inviting industry to develop propulsion systems based on less toxic propellants.

While ESA is pursuing possible exemptions for hydrazine for space uses, additional mitigation of this risk has been judged necessary, including the development of new ‘green’ propellants as a replacement for hydrazine and other high toxicity propellants along with associated hardware.

The Agency accordingly has issued a new Invitation To Tender: ‘LMP-103S System/Component Qualification Needs Evaluation’. The main goal is to identify the tasks and approach needed to qualify associated propulsion system hardware for use with LMP-103S, focused on small monopropellant thrusters (from 1 N to 20 N).

As of 2019, the exemption is still being discussed.

“In cases where we cannot replace the substance, then we pursue REACH authorisation to continue using it after the sunset date. So we’re currently in discussion on hydrazine to give one example, which is a case where we have a green propulsion technology roadmap, but the alternatives are not mature enough for adoption.

REACH is about far more than just hydrazine. ESA estimates that up to 20% of the industrial processes used in manufacturing launchers and satellites is potentially affected.


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