ChemicalBook > Articles Catagory List >Organic-Raw-Material >white-spirit-type-3-hydrogenated-hydrotreated-an-overview

White Spirit Type 3 "Hydrogenated (hydrotreated)"—— an Overview

Feb 21，2020

Isoparaffin l, synthesis grade, also called White Spirit Type 3 (EINECS number: 265-150-3; CAS number:64742-48-9) or hydrotreated heavy naphtha (petroleum) [1], is a complex combination of hydrocarbons obtained by treating a petroleum fraction with hydrogen in the presence of a catalyst. It consists of hydrocarbons having carbon numbers predominantly in the 6-13 range and boiling in the range of approximately 65 to 230°C (149 to 446°F) [2].

In Annex I of Guideline 67/548/EEC (EU 2004), this mixture is assigned to Carcinogen Category 2 if its benzene content is above 0.1% by weight. In practice, the benzene content has been below 0.005% (v/v) since the late 1970s. According to the definition of the CAS number, it is a mixture free of aromatic hydrocarbons (ACCOP 2001, 2004). If used in lubricant oils, aromatic hydrocarbons could be disruptive due to their susceptibility to oxidation and would form polycyclic aromatic hydrocarbons at high temperatures.

Article illustration

White Spirit Type 3 is used in the following products: fuels, air care products, anti-freeze products, coating products, lubricants and greases, washing & cleaning products and welding & soldering products. Other release to the environment of this substance is likely to occur from: indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters), outdoor use in close systems with minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and break fluids), indoor use as processing aid and outdoor use as processing aid [3].

There are no toxicological studies with a mixture accurately corresponding to the definition of CAS No. 64742-48-9. In practice, considerably narrower boiling ranges are used (for example Stoddard solvent IIC, White Spirit Type 3), for which toxicological studies are available. Studies carried out in the context of the US-HPV Challenge Program with a material that was supposed to correspond to this CAS No. (ACCOP 2001, 2004), used a different additional aromatic mixture and therefore cannot apply to hydrotreated heavy naphtha (petroleum).

Owing to the similar structure of these hydrocarbons, one can assume that oxidation of the alkyl chain or of the ring to alcohols, aldehydes and acids or ketones will presumably occur in all of them during metabolism. It is therefore to be expected that each compound of this category possesses a qualitatively similar toxicity to the other category members (CNS effects, liver tumours in the case of branched compounds, kidney toxicity). Up till now, the Commission has assessed the following substances that may be contained in the mixture according to the CAS No. definition:

Aliphatics: n-hexane, hexane isomers, n-heptane, octane and its isomers, trimethylpentane isomers.

Cycloaliphatics: cyclohexane, methylcyclohexane [4].

The advantage of using White Spirit Type 3 is its less intense odour compared to white spirit with aromatic content whereas it is difficult to discriminate between the toxicological properties of White Spirit Type 3 (no aromatics) and white spirit with aromatic content. In fact, White Spirit Type 3 was included in the proposal from Danish EPA when they put forward the classification proposal for white spirit for STOT RE1 proposal, as both WHO/IPCS 1996 and SCOEL (2007) concluded that the neurotoxic potential for White Spirit Type 3 should be considered the same as for the other white spirits with aromatic content. However, the RAC committee did not accept this proposal due to lack of specific data on the specific substance. Thus no clear toxicological advantage can be concluded when substituting to White Spirit Type 3 unless the vapour pressure of the White Spirit Type 3 is lower compared to the ‘old’ white spirit as this of course will reduce the inhalational exposure potential of the solvent [5].