Reference period (dimension)

Dimension of the Reference Period

---

The dimension of the time in which the Limit Value is defined. The following descriptions are in place:

Year Mostly used for calulation of the additional cancer mortality risk of carcinogenic substances;

Workdays (in dutch: werkdagen) Mostly used with Biological Monitoring Limit Values (f.e. in urine of the end shift at end of workweek);

Not critic The Reference Period is not critical in relation to the Limit Value. Mostly used with Biological Monitoring;

Not specified (in dutch: niet gespecificeerd). The Reference Period is not specified in the bibliographical source. Used as a rule of thumb in relation to certain fungi and bacteria;

Minutes mostly used as 15 minutes. This is also called the Short Term Exposure Level: STEL;

Long term (in dutch: lange termijn) Used in relation to the probability of an allergic reaction associated with the Limit Value;

Hours mostly used as an 8 hour time-weighted average (TWA), but also other values appear;

Days Mostly used with Biological Monitoring Limit Values (f.e. in urine at end of workweek);

Ceiling The Reference Period is 0. The absolute maximum, but in some occasions the substance can (only) be measured as 15-minute-STEL.