C₂Cl₄

Tetrachloroethylene is a halogenated chlorinated hydrocarbon used in industry as a solvent, degreaser, stain remover and in dry cleaning. It is a skin and mucous membrane irritant, it is hepatotoxic and nephrotoxic, and central nervous system depressant; it is a source of volatile substance abuse and can cause dependence. It is absorbed in the gastrointestinal tract, after inhalation and through the skin. It is excreted unchanged in exhaled air. 
Very good room ventilation is needed to keep the Threshold Limit Value - Time Weighted Average (TLV-TWA) below 20 ppm (138mg/m3). The Threshold Limit Value - Short-Term Exposure Limit (TLV-STEL), should be less than 40 ppm=275/m3. ^{(INSHT 2022).}

Accidental exposure for the mother is very dangerous: If it occurs, it is advisable to wait 1 week to breastfeed, since it concentrates in breast milk. A 6-week-old breastfed girl suffered severe jaundice; her mother was exposed after breastfeeding the same day her mother became intoxicated. ^{(Bagnell 1977)}

With regard to occupational risks for breastfeeding mothers ^{(INSHT 2022, UN 2011, EC Regulation 2008)}, there are only two risk phrases (old R-phrases, currently H-phrases for hazard) or precaution phrases (P-phrases) that should appear on the product’s safety data sheet:

• H362 (R64): "May cause harm to breast fed children"
• P263: "Avoid contact during pregnancy/while nursing”

Three other phrases that should be considered during breastfeeding are related to the carcinogenic, mutagenic or cumulative strength of a product:

• H350 (ant.R45 y R49): «May cause cancer»
• H351 (ant. R40): “Suspected of causing cancer"
• H370 (ant. R39): «Causes damage to organs».
• H371 (ant. R68): "May cause damage to organs”
• H372 (ant R48): «Causes damage to organs through prolonged or repeated exposure».
• H373 (ant. R33):" May cause damage to organs through prolonged or repeated exposure”

This product has the phrase H351 ("Possible carcinogenic effects"). ^{(INSHT 2022)}

According to current European regulations ^{(EC Regulation 2008)} when a product is carcinogenic and mutagenic, working nursing mothers should not be exposed to mixtures, whether of solids, liquids or gases, with concentration limits greater than 0.3%.