Ga-68 (Gallium-68) Radiation Safety Data

Source: Ionactive Radiation Protection Resource

Ga-68 (Gallium-68)

Half life: 1.13 days

Specific activity: 1.51×1018 Bq/g

Decay product: Zn-68 (stable)

Significant emissions (keV) [Ga-68 (Gallium-68)]

In the data below, % refers to the probability of emission of a particular type of radiation at a specified energy

Gamma / x-ray: 511 keV (178%), 1077 keV (3%), 1883 keV (<1%)

Beta (Emax): 882 keV (1%), 1899 keV (88%)


Alpha particles: n/a

Positron emitter and beta emitter.

External exposure (in air) [Ga-68 (Gallium-68)]

The values below are specified as mSv/h for either 1 MBq of activity or an area source of 1 MBq/m2 depending on the geometry. (HP 0.07) represents a skin dose rate and (HP 10) represents an 'at depth' tissue dose rate (> 10mm).

Point source (at 30cm)

Point source : 0.103 mSv/h [via beta emissions] and 0.00173 mSv/h [via gamma / photon emissions].

Infinite place source (at 10 cm)

Beta / electrons (HP 0.07) : 0.12 mSv/h

Photon (HP 0.07) : 0.0065 mSv/h (6.5 micro Sv/h)

Photons (HP 10) : 0.0062 mSv/h (6.2 micro Sv/h)

External exposure (arising from personal contamination) [Ga-68 (Gallium-68)]

The values below are either for uniform contamination on the skin (for 1 kBq/cm2) or as a single droplet (1 kBq) and are specified in mSv/h. It is assumed that no PPE is being worn which would attenuate the radiation.

Uniform deposit on the skin: 1.81 mSv/h (gamma dose rate)

0.05ml droplet on the skin: 1.25 mSv/h (gamma dose rate)

Shielding (external radiation) [Ga-68 (Gallium-68)]

In the data below beta shielding is specified as mm of material to provide 100% absorption of the beta particle (or electron). Gamma (and x-ray) shielding is specified in terms of mm of material relating to 1 TVT or 1 HVT. The TVT is the thickness of material (in mm) which will reduce the radiation intensity (dose rate) down to 1/10 of the pre-shielded dose rate. The HVT is the thickness of material (in mm) which will reduce the radiation intensity down to 1/2 of the pre-shielded dose rate

Beta radiation (for 100% absorption)

Glass: 3.9mm

Plastic: 7.2mm

Typical PPE (glove): negligible absorption (don't rely on gloves to shield for external radiation, they are a contamination control method).

Gamma / x-ray radiation (TVT and HVT)

Lead: 6mm (HVT) and 17mm (TVT)

Steel: 27mm (HVT) and 65mm (TVT)

Internal exposure [Ga-68 (Gallium-68)]

The data featured below is derived for employees who work with ionising radiation (and are therefore subject to dose limits specified by the Ionising Radiations Regulations 2017 in the UK, and similar regulation around the world). Whilst not directly applicable to public exposure (e.g. exposure resulting from environmental releases - either planned or accidental), the data will provide a good indication of likely exposures and is therefore adequate for general research, illustration and asking 'what if?' type questions. If you need professional advice, please consider consulting a Radiation Protection Adviser (RPA).

Internal radiation exposure generally means the intake of a radioactive substances by inhalation, ingestion or through cuts (or absorption) in the skin. For this resource assume cuts / absorption are similar to the ingestion values.

This data provides the dose delivered (committed effective dose equivalent) for an intake of [Ga-68 (Gallium-68)] by inhalation or ingestion to yield 1mSv effective dose. The dose value provided assumes that all the dose is delivered in the first year of intake, in reality this will vary greatly with radioisotope due to a combination of physical half-life, biological half-life and the biochemical behaviour of the particular radioactive substances in the body.

Target organ: Lower large intestine

Inhalation dose (1 mSv): 12.5 MBq

Ingestion dose (1 mSv): 10 MBq

Atoms are very special: they like certain particular partners, certain particular directions, and so on. It is the job of physics to analyze why each one wants what it wants.

– Richard P. Feynman -