1,2,4-Trichlorobenzene

City of Friendswood

1,2,4-Trichlorobenzene is an industrial solvent that can harm the adrenal glands and may increase the risk of cancer.

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2013	N/A	0	N/A
2014	ND	2	ND
2015	ND	4	ND
2016	ND	6	ND
2017	ND	4	ND
2018	ND	4	ND
2019	ND	6	ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 5 ppb

The EWG Health Guideline of 5 ppb for 1,2,4-trichlorobenzene was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hormone disruption.

EPA Maximum Contaminant
Level (MCL) 70 ppb

The legal limit for 1,2,4-trichlorobenzene, established in 1992, was based on a toxicity study in laboratory animals conducted in 1981. This limit may not fully protect against hormone disruption.

ppb = parts per billion

All test results

Date	Lab ID	Result
2014-02-20	AC43875	ND
2014-02-20	AC43867	ND
2015-02-05	AC79512	ND
2015-02-05	AC79510	ND
2015-02-05	AC79506	ND
2015-02-05	AC79514	ND
2016-02-04	AD22119	ND
2016-02-04	AD22173	ND
2016-02-04	AD22161	ND
2016-02-04	AD22177	ND
2016-09-28	AD51724	ND
2016-10-26	AD54839	ND
2017-01-19	AD65743	ND
2017-01-19	AD65723	ND
2017-01-19	AD65721	ND
2017-05-03	AD82490	ND
2018-01-29	AE11006	ND
2018-05-21	AE27042	ND
2018-05-21	AE27044	ND
2018-09-17	AE40251	ND
2019-02-04	AE52712	ND
2019-02-04	AE52710	ND
2019-02-04	AE52716	ND
2019-02-04	AE52718	ND
2019-04-22	AE63211	ND
2019-07-15	AE74435	ND