Table 2.
Some common ingredients in natural repellents that may be hazardous. Reproduced with permission from [63]
| Common Name | Scientific Name | Safe Concentration | Hazard |
|---|---|---|---|
| Anise | Pimpinella anisum | 3.6% | Based on 0.11% methyl eugenol; carcinogen |
| Basil | Ocimum sp | 0.07% | Based on 6% methyl eugenol; carcinogen |
| Bergamot | Citrus aurantium bergamia | 0.4% | Sensitising and phototoxic; skin irritant |
| Cajeput | Melaleuca alternifolia | 0.004% | Based on 97% methyl eugenol; carcinogen |
| Cedar | Chamaecyparis nootkatensis | 1% | Likely allergenic contaminants if nootkatone not 98% pure |
| Cassia | Cinnamonium cassia | 0.2% or 9% | Sensitising skin irritant |
| Citronella | Cymbopogon nardus | 2% | Safety is controversial; based on 0.2% methyl eugenol or 1.3% citral; sensitising skin irritant |
| Citronella (Java) | Cymbopogon winterianius | 2% | Based on 0.2% methyl eugenol; carcinogen |
| Citrus oils | Citrus sp | 16-25% | Based on 0.005%-0.0025% bergapten; phototoxic skin irritant |
| Clove | Syzyguim aromaticum | 0.5% | Based on 92% eugenol; sensitising skin irritant |
| Fever tea, lemon bush | Lippia javanica | 2% | Based on 5% citral in related species; sensitising skin irritant |
| Geranium | Pelargonium graveolens | 6% | Based on 1.5% citral; sensitising skin irritant |
| Ginger | Zingiber sp | 12% | Based on 0.8% citral; sensitising skin irritant |
| Huon oil, Macquarie pine | Langarostrobus franklini | 0.004% | Based on 98% methyl eugenol; carcinogen |
| Lemongrass | Cymbopogon citratus | 0.1% | Based on 90% citral; sensitising skin irritant |
| Lime | Citrus aurantifolia | 0.7% | Phototoxic skin irritant |
| Litsea | Litsea cubeba | 0.1% | Based on 78% citral; sensitising skin irritant |
| Marigold | Tagates minuta | 0.01% | Phototoxic skin irritant |
| Mexican tea, American wormseed | Chenopodium ambrosioides | Prohibited | Toxic |
| Mint | Mentha piperata and spicata | 2% | Based on 0.1% trans-2-hexenal; sensitising skin irritant |
| Nutmeg | Myristica fragrans | 0.4% | Based on 1% methyl eugenol; carcinogen |
| Palmarosa | Cymbopogon martini | 16% | Based on 1.2% farnesol; sensitizing skin irritant |
| Pennyroyal | Mentha pulegium or Hedeoma pulegioides | Prohibited | Toxic |
| Pine | Pinus sylvestris | Prepare with antioxidants | Oxidation creates phototoxic skin irritants |
| Rosemary | Rosemarinus officinalis | 36% | Based on 0.011% methyl eugenol; carcinogen |
| Rue | Ruta chalepensis | 0.15% | Based on presence of psoralenes; phototoxic skin irritant |
| Thyme | Thymus vulgaris | 2% | Based on 0.1% trans-2-hexenal; sensitising skin irritant |
| Violet | Viola odorata | 2% | Based on 0.1% trans-2-hexenal; sensitising skin irritant |
| Ylang-ylang | Canagium odoratum | 2% | Based on 4% farnesol; sensitizing skin irritant |