The facts on 1,2-Dichloropropane

No estimates of current numbers of exposed workers to 1,2-Dichloropropane (1,2-DPC) in the EU are available. Inhalation is considered as the primary route of exposure although workers can be exposed through dermal contact as well.

1,2-DPC is classified as Carcinogenic Category 1B (according to CLP Regulation), which means it is presumed to have carcinogenic potential for humans, based on animal evidence.

The toxic effects have included liver and kidney damage, intravascular coagulation, haemolytic anaemia and various central nervous system symptoms.

Where risks occur

1,2-DCP is a by-product, produced in significant quantities, during the manufacturing process of propylene oxide by the chlorohydrin process to produce epichlorohydrin. 1,2-DCP was historically used as a soil fumigant, chemical intermediate, as well as an industrial solvent. It was found in paint strippers, varnishes, and furniture finish removers. It is no longer used as a soil fumigant.

Currently, its main use is as an intermediate in the manufacture of perchloroethylene and other chlorinated chemicals.
In general, workplace exposure appears to be limited due to handling under strictly controlled conditions. The main activity where exposure is possible is during manual maintenance or cleaning activities.

More about the substance

In its pure form, 1,2-DPC is a colourless, flammable, mobile liquid with a chloroform-like odour. It is miscible with most organic solvents, such as alcohols, esters, and ketones, as well as with aromatic, aliphatic, and chlorinated hydrocarbons.
An EU-wide binding occupational exposure limit value is currently under preparation.

Hazards that may occur

Short-term exposure to 1,2-DCP in humans may cause irritation, as well as liver and kidney dysfunction following oral and dermal absorption. At very high concentrations, central nervous system depression has been reported.
For long-term exposure, the most critical effect in humans is carcinogenity, specifically the occurrence of bile duct tumours (Cholangiocarcinoma).

What you can do

At the workplace, the most effective way to prevent exposure is by substitution of 1,2-DCP. Where substitution is not possible and use of 1,2-DCP cannot be avoided, measures to reduce exposure must be taken.
The most effective way to avoid exposure to 1,2-DCP is to develop and use closed systems. Where this is not possible, technical measures such as effective local exhaust ventilation, supplemented by good general workplace ventilation and regular checks of their effectiveness, should be implemented to ensure that exposure is minimised as much as technically possible

All production of 1,2-DPC takes place within closed systems. Exposure takes place when these closed systems are opened for routine maintenance, inspections, or cleaning. In those cases, technical measures and PPE, including RPE, need to be used.

Implement measures to ensure a proper general workplace hygiene with regular cleaning and hygienic storage. After the initial exposure measurement for risk assessment, perform periodic exposure assessments to check if your technical measures in place are effective or whether further actions need to be taken. Strictly limiting the time workers spend in exposed working environment (e.g., via shifts) and restricting the access to those workplaces are important measures to reduce exposure. Workers have to be aware of the possible risks associated with tasks involving 1,2-DPC and employers have to train and instruct them regularly on how to work safely with 1,2-DPC.

Medical health surveillance is required for workers exposed to hazardous substances and accordingly they should be encouraged to report early symptoms such as respiratory problems or skin allergies.
In addition, train workers on the importance of effective personal hygiene. Provide adequate washing and toilet facilities and allow workers ample time for hygienic measures.

Ensure that workers have adequate personal protective equipment, such as protective clothing and gloves, if necessary. Personal protective equipment should only be used as a last resort and only considered temporarily, after the possible technical and organisational solutions have been exhausted.

References: ECHA, ATSDR 2021