Smeets Monique, Dalton Pamela
Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
Int Arch Occup Environ Health. 2002 Oct;75(8):541-8. doi: 10.1007/s00420-002-0364-y. Epub 2002 Aug 16.
To assess sensory irritation levels from isopropanol (IPA) unconfounded by subjective evaluations of odor for comparison against the recommended exposure limits (400 ppm threshold limit value (TLV); American Conference of Governmental Industrial Hygienists).
The lateralization method was used to assess intra-nasal irritation thresholds for IPA, while odor detection thresholds were also measured. Thresholds for 1-butanol and phenyl ethyl alcohol (PEA) were obtained as positive and negative irritant controls. To compare potency and hedonic characteristics, subjects provided subjective ratings of odor, irritation and annoyance intensity for three concentrations of each chemical. Workers occupationally exposed to IPA ( n=26) were compared with previously unexposed controls ( n=26).
The (geometric) mean odor detection threshold for IPA was slightly higher among exposed workers than controls (39 ppm vs. 11 ppm). Lateralization thresholds measuring intra-nasal irritation were elevated when compared with controls (6,083 ppm in exposed workers vs. 3,361 ppm in naïve controls), with a significantly higher proportion of phlebotomists being unable to lateralize the maximum concentration regarded as safe, than controls. Calculations of the 6th percentile for lateralization thresholds revealed that 95% of the sample did not experience sensory irritation below 512 ppm. Thus, while odor detection thresholds were well below the current recommended exposure limits, the irritation thresholds were well above these values. The odor, irritation and annoyance from IPA was perceived, on average, as between weak and almost strong, from lowest to highest concentration.
The results indicate that current exposure guidelines would be adequately protective of the acute adverse effect of nasal sensory irritation, as operationally defined by the intra-nasal lateralization threshold. Exposures to higher concentrations should perhaps be evaluated on the basis of existing knowledge about systemic, rather than local (e.g., irritation), toxic effects. IPA appears to be a weak sensory irritant and occupational exposure to IPA appears to elicit small changes in sensitivity that do not generalize to other odorants (e.g., PEA and 1-butanol) and are likely to be reversible.
评估异丙醇（IPA）引起的感觉刺激水平，排除气味主观评价的干扰，以便与推荐暴露限值（400 ppm阈限值（TLV）；美国政府工业卫生学家会议）进行比较。
采用偏侧化方法评估IPA的鼻内刺激阈值，同时测量气味检测阈值。获得1-丁醇和苯乙醇（PEA）的阈值作为阳性和阴性刺激对照。为了比较效力和享乐特征，受试者对每种化学品的三种浓度的气味、刺激和烦恼强度进行主观评分。将职业接触IPA的工人（n = 26）与未接触过的对照组（n = 26）进行比较。
接触过IPA的工人中，IPA的（几何）平均气味检测阈值略高于对照组（39 ppm对11 ppm）。与对照组相比，测量鼻内刺激的偏侧化阈值升高（接触过IPA的工人为6,083 ppm，未接触过的对照组为3,361 ppm），与对照组相比，采血员中无法对视为安全的最大浓度进行偏侧化的比例明显更高。偏侧化阈值第6百分位数的计算表明，95%的样本在512 ppm以下未经历感觉刺激。因此，虽然气味检测阈值远低于当前推荐的暴露限值，但刺激阈值远高于这些值。从最低浓度到最高浓度，IPA的气味、刺激和烦恼平均被感知为介于微弱和几乎强烈之间。
结果表明，按照鼻内偏侧化阈值在操作上定义，当前的暴露指南能充分保护免受鼻感觉刺激的急性不良反应。也许应根据关于全身毒性作用而非局部（如刺激）毒性作用的现有知识，对更高浓度的暴露进行评估。IPA似乎是一种弱感觉刺激物，职业接触IPA似乎会引起敏感性的微小变化，这种变化不会推广到其他气味剂（如PEA和1-丁醇），并且可能是可逆的。
