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Description of key information

No deaths or other severe adverse affects were reported in a number of acute oral studies, in which rats were given single doses of C14-17 chlorinated paraffins (40-61% chlorination; with or without 0.2-1% epoxy stabiliser) of up to 15 g/kg bw by stomach tube. There are no acute inhalation or dermal exposure studies on MCCPs available in laboratory animals. However, based upon animal data for SCCPs, and supported by the low toxicity of C14-17 chlorinated paraffins via the oral route, it is predicted that the MCCPs are also likely to be of low acute inhalation and dermal toxicity. No acute human data is available. 

Key value for chemical safety assessment

Additional information

No deaths or other severe adverse effects were seen in a number of unpublished studies in which rats were administered single oral doses of C14-17 chlorinated paraffins (40-52% chlorination, containing 0.2-1% epoxy stabiliser) of up to 15 g/kg bw by stomach tube. Clinical signs of toxicity were confined to urinary incontinence or "oily/moist pelt around the anal-genital region" during the first 24-48 h following administration (Chater, 1978; Kuhnert, 1986a,b). According to a review, no mortality was seen up to 14 days after groups of at least three rats were administered a single oral dose of one of eight samples of C14-17 chlorinated paraffins (chlorinated to between 51 and 60%, with or without 0.2% epoxy stabiliser) at 0.5 to 10 g/kg bw. It is not possible to confidently ascertain the adverse effects seen in these studies due to the limitations in reporting, however, the acute oral LD50 was noted as greater than 4 g/kg bw (Birtley et al. 1980).

 

No acute inhalation toxicity studies are available on MCCPs. However, no evidence of toxicity were seen in rats following a 1 h exposure to air containing a C12 chlorinated paraffin (59% chlorination) at about 3300 mg/m3 (3.3 mg/L) (Howard et al. 1975). In addition, no deaths were reported, but slight eye and nose irritation was seen, in rats exposed to a SCCP of unspecified carbon length (50% chlorination) for 1 h at 48,000 mg/m3 (48 mg/L) (ICI, 1974). In view of the similarities in structure and physicochemical properties of MCCPs and SCCPs, it is predicted that MCCPs would also be of low toxicity folowing single inhalation exposure. This is supported by the observation of low toxicity of MCCPs by oral routes and the generally unreactive nature of these substances.

 

No acute dermal toxicity studies are available on MCCPs. However, a C10-13 chlorinated paraffin (52% chlorination) was tested for acute dermal toxicity at 2.5 ml/kg bw (about 2.8 g/kg bw) in a well-conducted study (ICI, 1971). When applied undiluted (occlusive for 24 h) to groups of 3 rats, no deaths or signs of systemic toxicity were reported (although slight local irritation was seen in the seven day observation period). In addition, an LD50 value of 10 ml/kg bw (approximately 13.5 g/kg bw) was reported in rabbits treated with a C12 chlorinated paraffin (59% chlorination) (Howard et al. 1975). As SCCPs have been demonstrated to be of low toxicity by this route, and in consideration of the structural and physicochemical similarities, together with the low acute oral toxicity and low skin absorption of MCCPs, it can be predicted that MCCPs are likely to be of low acute toxicity by the dermal route of exposure.

No information is available on the effects of single exposure to MCCPs in humans (via any route). Similar is true of the SCCPs (EU, 2000).

Justification for classification or non-classification

The acute oral LD50 for C14-17 chlorinated paraffins in rats is greater than 2 g/kg bw. No deaths were seen in acute inhalation studies in rats exposed to air containing a C12 chlorinated paraffin (59% chlorination) at 3300 mg/m3 (3.3 mg/L) or a 50% chlorinated SCCP (of unspecified chain length) at 48,000 mg/m3 (48 mg/L) for 1 h. The acute dermal LD50 of a C10-13 chlorinated paraffin (52% chlorinated) in rats and a C12 chlorinated paraffin (59% chlorinated) in rabbits is greater than 2 g/kg bw. According to EU CLP and DSD regulations, under the conditions of these studies, C14 -17 chlorinated paraffins would not be classified as acutely toxic by the oral, dermal or inhalation routes.