Agents used for crowd control, such as CS gas, CR gas, CN gas, and pepper sprays, including PAVA, are potent, rapidly incapacitating sensory irritants and lacrimators. They cause irritation of the mucous membranes of the eyes, nose, mouth and throat that is short-lived, usually resolving spontaneously within 15-30 minutes. Systemic toxicity, although rare, is occasionally observed after CN exposure, especially at high concentrations. CS gas, CR gas and CN gas are often formulated to include organic solvents that allow their dispersal as aerosols. PAVA spray has replaced CS gas as the crowd control agent used by UK police forces.
There are very limited preclinical and human data available concerning acute exposure to CS gas in pregnancy, and no available data for CR gas, CN gas, or pepper sprays. Available data on CS gas used for crowd control do not indicate an association with adverse effects on the fetus but are too limited to exclude an increased risk. Significant systemic toxicity is generally not expected following exposure to crowd control agents (other than expected lacrimatory effects), but patients with pre-existing medical conditions such as asthma or cardiovascular disorders may be at risk of systemic effects. If treatment is required, pregnant women should be treated as for the non-pregnant patient.
Exposure to crowd control agents at any stage of pregnancy would not usually be regarded as medical grounds for termination of pregnancy. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments. Where exposure to crowd control agents has occurred, even in the absence of maternal toxicity, enhanced fetal monitoring may be warranted, particularly in cases associated with maternal hypoxia or signs of systemic toxicity. Discussion with UKTIS is recommended in all cases of exposure.
This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to NHS health care professionals who are logged in.
If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.
If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.