 Commonwealth of Australia 2002

14.2Hazard communication

14.2.1Labels

Under the current NOHSC List of Designated Hazardous Substances (NOHSC, 1999a), CAS number 138-86-3 is specifically listed with the names p-mentha-1,8(9)-diene and dipentene. The name limonene or CAS numbers of the d- and l- isomers are not specifically listed. Guidance to the List states that chemicals with different isomers may be listed generically without mention of each isomer, and that the label text should designate the particular isomer or isomers marketed. In this case, the method of listing may have made the chemical difficult to locate on the List, if d- or l-limonene was being used rather than dipentene.

A small number of labels for limonene or dipentene were submitted during the assessment. A formal assessment of labels was not carried out. However it was noted that all listed a classification according to the ADG Code, but different UN numbers were used. Some did not clearly list risk and safety phrases applicable to limonene. The risk phrases on some labels varied from those on the NOHSC Designated List.

On some labels a signal word was not stated clearly, and procedures in the case of fire were omitted. These label defects could hinder the handling of an emergency.

The expiry date relevant to the shelf life of the product was not shown on the sample labels, but may be marked on containers in another way.

14.2.2Material Safety Data Sheets

MSDS were provided by 14 suppliers of limonene or dipentene in Australia and one supplier of a product with a high limonene content. All were dated and were issued between 1997-2001. Although a formal assessment was not carried out, the following points were noted regarding the different sections of the MSDS:

Statement of hazardous nature

Three MSDS omitted this statement. One stated incorrectly that the chemical is not considered hazardous;

Identification

Products were described as limonene (d- or dl-) and dipentene, but also often as “Terpene hydrocarbons NOS (d-limonene)”, reflecting the shipping name commonly assigned to d-limonene. Commercial grades of dipentene containing < 50% limonene were identified as “terpene hydrocarbons” or “pine oil 65%”. Pure (> 95%) grades of d-limonene were also identified as “citrus terpenes”, “orange terpenes” or “orange oil terpenes”;

Almost all MSDS included the correct Hazchem code 3[Y] and Packing Group (III). The UN number assigned to dipentene (2052) was also used by some suppliers for d-limonene. Other suppliers of d-limonene used UN 2319, which is the code for Terpene Hydrocarbons NOS. The MSDS for a grade of pine oil containing limonene was coded as UN 1272; and

In general the MSDS contained substantial information on physical description and properties. However, the important parameters boiling point, vapour pressure, and flashpoint were missing from some MSDS, and 5 did not have data for flammability limits.

Health hazard information

Most MSDS distinguished between acute and chronic effects, and routes of exposure;

Skin irritation is a listed effect under the NOHSC List of Designated Hazardous Substances (NOHSC, 1999a). All MSDS acknowledged an effect on skin, although a few described the effects as redness, drying or defatting rather than irritation. Dermatitis was mentioned without distinguishing between irritant contact dermatitis and allergic contact dermatitis;

The skin sensitisation effect of limonene is not yet listed in the NOHSC List of Designated Hazardous Substances (NOHSC, 1999a). However, this effect was mentioned on 6 MSDS;

Eye irritation was mentioned on almost all MSDS; and

Most first aid instructions recommended that vomiting should not be induced, but did not explain that this is primarily to avoid aspiration.

Precautions for use

Most MSDS advised that there was no NOHSC exposure standard but a few did not cover the topic at all;

Ventilation was the main engineering control mentioned, and advice varied from exhaust ventilation to “no special requirements”. A few MSDS noted that as limonene vapour is heavier than air, it will collect in low areas and that extraction should deal with this vapour accumulation;

Glove material most commonly recommended in MSDS was PVC, rubber, neoprene or butyl. Other materials have been reported as having high resistance to limonene (Section 14.1). Eye protection was recommended in all MSDS. For exposure to a high vapour level or in confined space, self contained breathing apparatus (SCBA) was generally recommended;

Several MSDS wrongly identified limonene as a combustible liquid instead of a flammable liquid. Precautions to avoid fire were not included in this section in 2 MSDS, and in general were covered only briefly; and

Only one MSDS covered the risk of spontaneous combustion of rags soaked in limonene and the risk of distilling material containing peroxides.

Safe handling information

Information on storage should cover both the flammability and stability aspects of the chemical, but this was done in only a small number of MSDS;

Transport classification information was stated on most MSDS, and some also included information on segregation of different classes of dangerous goods;

Information on spills and disposal often did not distinguish procedures for small and large spills; and

The primary fire extinguishing materials recommended in MSDS were dry chemical, CO₂ and foam. Varied advice was given on use of water in firefighting. In general MSDS did not comprehensively cover all the factors relevant to limonene in a fire – flammability, explosion hazard, immiscibility with water, high vapour density and ability to accumulate static charge.

Contact point

A majority of MSDS included contact information in Australia, and indicated whether this was available 24 hours a day or only during business hours.

14.2.3Education and training

Guidelines for the induction and training of workers exposed to hazardous substances are provided in the NOHSC Model Regulations and Code of Practice for the Control of Workplace Substances (NOHSC, 1994a; NOHSC, 1994b). Under the regulations employers are obliged to provide training and education to workers handling hazardous substances.